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Yvonne Lim Ai Lian

Department of Parasitology, Faculty of Medicine University of Malaya, 50603 Kuala Lumpur, MALAYSIA
limailian@um.edu.my

Journal articles

2012
Y A L Lim, M A K Mahdy, T K Tan, X T Goh, A R Jex, M J Nolan, R S K Sharma, R B Gasser (2012)  First molecular characterization of Giardia duodenalis from goats in Malaysia   Molecular and Cellular Probes August  
Abstract: In the present study, 310 faecal samples from goats from eight different farms in Malaysia were tested for the presence of Giardia using a PCR-coupled approach. The nested PCR for SSU amplified products of the expected size (â¼200 bp) from 21 of 310 (6.8%) samples. Sixteen of these 21 products could be sequenced successfully and represented six distinct sequence types. Phylogenetic analysis of the SSU sequence data using Bayesian Inference (BI) identified Giardia assemblages A, B and E. The identification of the 'zoonotic' assemblages A and B suggests that Giardia-infected goats represent a possible reservoir for human giardiasis in Malaysia.
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A Iqbal, Y A L Lim, J Surin, B L H Sim (2012)  High Diversity of Cryptosporidium Subgenotypes Identified in Malaysian HIV/AIDS Individuals Targeting gp60 Gene   Plos One 7: 2. Feb  
Abstract: Background: Currently, there is a lack of vital information in the genetic makeup of Cryptosporidium especially in developing countries. The present study aimed at determining the genotypes and subgenotypes of Cryptosporidium in hospitalized Malaysian human immunodeficiency virus (HIV) positive patients. Methodology/Principal Findings: In this study, 346 faecal samples collected from Malaysian HIV positive patients were genetically analysed via PCR targeting the 60 kDa glycoprotein (gp60) gene. Eighteen (5.2% of 346) isolates were determined as Cryptosporidium positive with 72.2% (of 18) identified as Cryptosporidium parvum whilst 27.7% as Cryptosporidium hominis. Further gp60 analysis revealed C. parvum belonging to subgenotypes IIaA13G1R1 (2 isolates), IIaA13G2R1 (2 isolates), IIaA14G2R1 (3 isolates), IIaA15G2R1 (5 isolates) and IIdA15G1R1 (1 isolate). C. hominis was represented by subgenotypes IaA14R1 (2 isolates), IaA18R1 (1 isolate) and IbA10G2R2 (2 isolates). Conclusions/Significance: These findings highlighted the presence of high diversity of Cryptosporidium subgenotypes among Malaysian HIV infected individuals. The predominance of the C. parvum subgenotypes signified the possibility of zoonotic as well as anthroponotic transmissions of cryptosporidiosis in HIV infected individuals.
Notes: Iqbal, Asma Lim, Yvonne A. L. Surin, Johari Sim, Benedict L. H.
C H Chew, Y A L Lim, P C Lee, R Mahmud, K H Chua (2012)  A hexaplex PCR detection system for the identification of five human Plasmodium species with internal control   Journal of Clinical Microbiology Oct  
Abstract: Malaria remains as one of the major killers of humankind and persists to threaten the lives of more than one-third of the world's population. Given that human malaria can now be caused by five species of Plasmodium, i.e., Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae, Plasmodium ovale, and the recent inclusion of Plasmodium knowlesi, there is a critical need not only to augment global health efforts in malaria control but more importantly to develop a rapid, accurate, species-sensitive/-specific and economically-effective diagnosis for malaria caused by these five species. Therefore, in the present study, a straightforward single step hexaplex PCR system targeting five human Plasmodium 18S small subunit ribosomal RNA (ssu rRNA) were designed and the system has successfully detected all five human malaria parasites. In addition, this system enables the differentiation of single infection as well as mixed infections up to two species level. This assay was validated with 50 randomly blind test and 184 clinical samples suspected with malaria. This hexaplex PCR system is not only an ideal alternative for routine malaria diagnosis in laboratories with conventional PCR machines but also adds value to diagnosis when there is a lack of experienced microscopist or/and when the parasite morphology is confusing. Indeed, this system will definitely enhance the accuracy and accelerate the speed in the diagnosis of malaria as well as improve the efficacy in malaria treatment and control, in addition to providing reliable data in epidemiological surveillance studies.
Notes: Chew, Ching Hoong xD;Lim, Yvonne Ai Lian xD;Lee, Ping Chin xD;Mahmud, Rohela xD;Chua, Kek Heng xD;ENG xD;2012/10/05 06:00 xD;J Clin Microbiol. 2012 Oct 3.
M Rohela, R Ngui, Y A Lim, B Kalaichelvan, W I Wan Hafiz, A N Mohd Redzuan (2012)  A case report of Hymenolepis diminuta infection in a Malaysian child   Trop Biomed 29: 2. 224-30 Jun  
Abstract: We report a case of Hymenolepis diminuta infection in a 2-year-old Malaysian child. This case was initially reported as 'normal' after the examination of proglottids shed from the anus of the child at a private laboratory on two occasions. The putative proglottids shed was then referred to the Parasite Southeast Asia Diagnostic (Para:SEAD) Laboratory, Department of Parasitology, Faculty of Medicine, University of Malaya for further examination. Microscopic examination confirmed that the child was infected with H. diminuta based on the characteristic eggs found in the proglottids. She was treated with a single dose praziquantel (20 mg/kg of body weight) and recovered well.
Notes: Rohela, M xD;Ngui, R xD;Lim, Y A L xD;Kalaichelvan, B xD;Wan Hafiz, W I xD;Mohd Redzuan, A N xD;eng xD;Malaysia xD;2012/06/28 06:00 xD;Trop Biomed. 2012 Jun;29(2):224-30.
M A K Mahdy, Y A L Lim, R Ngui, M R S Fatimah, S H Choy, N J Yap, H M Al-Mekhlafi, J Ibrahim, J Surin (2012)  Prevalence and zoonotic potential of canine hookworms in Malaysia   Parasites & Vectors 5: May  
Abstract: Background: Canine hookworm infection is endemic in Southeast Asian countries with a prevalence ranging from 70% to 100%, with zoonotic transmission representing a potentially significant public health concern. However, there are limited data available on the prevalence of canine hookworms in Malaysia. This study was conducted to determine the prevalence of hookworm and Ancylostoma species among dogs in Malaysia. xD; Methods: Faecal samples were collected from 221 dogs living in urban areas, rural areas and animal shelters in Selangor. Faecal samples were processed using the formal-ether concentration technique followed by wet mount preparation and iodine staining for the detection of hookworm eggs. Samples positive for hookworm eggs were examined using PCR, targeting ITS2 and 28 s rRNA region, and subsequently sequenced in both directions. The sequences were phylogenetically analysed using MrBayes for Bayesian Inference. xD; xD;Results: The overall prevalence of hookworm among dogs was 48% (95% CI; 41.41-54.95). Rural stray dogs had the highest prevalence 71.4% (95% CI; 61.13-81.49) followed by urban stray dogs, recording 48% (95% CI; 34.15-61.85) and lastly dogs in shelters with 28.7% (95% CI; 19.56-37.84). Logistic regression identified rural stray dogs as a high risk group (OR = 4.55, 95%; 2.50-8.31) and keeping dogs in shelters as a protective factor (OR = 0.24, 95%; 0.14-0.43). Molecular methods identified both Ancylostoma ceylanicum and Ancylostoma caninum with A. ceylanicum being predominant among urban stray dogs. Rural dogs had a higher prevalence of A. caninum than A. ceylanicum, while both species showed equal distribution among dogs in shelters. Phylogenetic analysis placed A. ceylanicum isolated from dogs in one group with A. ceylanicum human isolates. xD; xD;This study indicates that dogs have the potential to act as reservoir hosts of human hookworm infection in Malaysia. This finding necessitates the inclusion of dogs in any interventions to combat hookworm in the country.
Notes: Mahdy, Mohammed A. K. Lim, Yvonne A. L. Ngui, Romano Fatimah, M. R. Siti Choy, Seow H. Yap, Nan J. Al-Mekhlafi, Hesham M. Ibrahim, Jamaiah Surin, Johari
S Aziz, R Ngui, Y A L Lim, I Sholehah, J N Farhana, A S Azizan, W W S Yusoff (2012)  Spatial pattern of 2009 dengue distribution in Kuala Lumpur using GIS application   Tropical Biomedicine 29: 1. 113-120 March  
Abstract: In the last few years in Malaysia, dengue fever has increased dramatically and has caused huge public health concerns. The present study aimed to establish a spatial distribution of dengue cases in the city of Kuala Lumpur using a combination of Geographic Information System (GIS) and spatial statistical tools. Collation of data from 1,618 dengue cases in 2009 was obtained from Kuala Lumpur City Hall (DBKL). These data were processed and then converted into GIS format. Information on the average monthly rainfall was also used to correlate with the distribution pattern of dengue cases. To asses the spatial distribution of dengue cases, Average Nearest Neighbor (ANN) Analysis was applied together with spatial analysis with the ESRI ArcGIS V9.3 programme. Results indicated that the distribution of dengue cases in Kuala Lumpur for the year 2009 was spatially clustered with R value less than 1 (R = 0.42; z-scores = - 4.47; p < 0.001). Nevertheless, when this pattern was further analyzed according to month by each zone within Kuala Lumpur, two distinct patterns were observed which include a clustered pattern (R value < 1) between April to June and a dispersed pattern (R value > 1) between August and November. In addition, the mean monthly rainfall, has not influenced the distribution pattern of the dengue cases. Implementation of control measures is more difficult for dispersed pattern compared to clustered pattern. From this study, it was found that distribution pattern of dengue cases in Kuala Lumpur in 2009 was spatially distributed (dispersed or clustered) rather than cases occurring randomly. It was proven that by using GIS and spatial statistic tools, we can determine the spatial distribution between dengue and population. Utilization of GIS tools is vital in assisting health agencies, epidemiologist, public health officer, town planner and relevant authorities in developing efficient control measures and contingency programmes to effectively combat dengue fever.
Notes: Aziz, S. Ngui, R. Lim, Y. A. L. Sholehah, I Farhana, Nur J. Azizan, A. S. Yusoff, Wan W. S.
R Ngui, L Angal, S A Fakhrurrazi, Y L A Lian, L Y Ling, J Ibrahim, R Mahmud (2012)  Differentiating Entamoeba histolytica, Entamoeba dispar and Entamoeba moshkovskii using nested polymerase chain reaction (PCR) in rural communities in Malaysia   Parasites & Vectors 5: 187 September  
Abstract: Background: In this study, a total of 426 human faecal samples were examined for the presence of Entamoeba histolytica, Entamoeba dispar, Entamoeba moshkovskii infection via a combination of microscopic examination and nested polymerase chain reaction (PCR) targeting 16S ribosomal RNA of Entamoeba species. xD; xD;Methods: Faecal sample were collected from 426 participants in five rural villages in Peninsular Malaysia. The faecal samples were processed by direct wet smear and formalin ethyl acetate concentration technique followed by iodine staining and examined via microscopy for the presence of Entamoeba species and other intestinal parasites. Microscopically positive samples for Entamoeba species cysts were further characterized using a Nested Polymerase Chain Reaction (Nested-PCR) targeting 16S-like ribosomal RNA gene. The data entry and analysis was carried out using the SPSS software (Statistical Package for the Social Sciences) program for Windows version 17 (SPSS, Chicago, IL, USA). xD; xD;Results: Based on single faecal examination, overall prevalence of Entamoeba infection was 17.6% (75/426). Females (19.1%) were more commonly infected compared to males (15.9%). Comparison by age groups showed that adults (23.9%) had higher infection rates than children (15.3%). The PCR results showed that 52 out of 75 microscopy positive samples successfully generated species-specific amplicons. The infection with E. histolytica (75.0%; 39/52) was the most common, followed by E. dispar (30.8%; 18/52) and E. moshkovskii (5.8%; 3/52). Of these, 33 (63.5%) were shown to contain only E. histolytica, 10 (19.2%) contained E. dispar and 3 (5.8%) contained only E. moshkovskii. Mixed infection with E. histolytica and E. dispar was found in 6 (11.5%) samples. xD; xD;The present study essentially emphasized the benefit of molecular techniques in discriminating the xD;pathogenic Entamoeba species from the non-pathogenic for accurate diagnosis and better management of amoebiasis. xD;The presence of E. moshkovskii is of great public health concern as it was the first time it has been reported in Malaysia.
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R Ngui, Y A L Lim, L C Kin, C S Chuen, S Jaffar (2012)  Association between Anaemia, Iron Deficiency Anaemia, Neglected Parasitic Infections and Socioeconomic Factors in Rural Children of West Malaysia   Plos Neglected Tropical Diseases 6: 3. March  
Abstract: Background: Given that micronutrient deficiency, neglected intestinal parasitic infections (IPIs) and poor socioeconomic status are closely linked, we conducted a cross-sectional study to assess the relationship between IPIs and nutritional status of children living in remote and rural areas in West Malaysia. Methods/Findings: A total of 550 children participated, comprising 520 (94.5%) school children aged 7 to 12 years old, 30 (5.5%) young children aged 1 to 6 years old, 254 (46.2%) boys and 296 (53.8%) girls. Of the 550 children, 26.2% were anaemic, 54.9% iron deficient and 16.9% had iron deficiency anaemia (IDA). The overall prevalence of helminths was 76.5% comprising Trichuris trichiura (71.5%), Ascaris lumbricoides (41.6%) and hookworm infection (13.5%). It was observed that iron deficiency was significantly higher in girls (p = 0.032) compared to boys. Univariate analysis demonstrated that low level of mother's education (OR = 2.52; 95% CI = 1.38-4.60; p = 0.002), non working parents (OR = 2.18; 95% CI = 2.06-2.31; p = 0.013), low household income (OR = 2.02; 95% CI = 1.14-3.59; p = 0.015), T. trichiura (OR = 2.15; 95% CI = 1.21-3.81; p = 0.008) and A. lumbricoides infections (OR = 1.63; 95% CI = 1.04-2.55; p = 0.032) were significantly associated with the high prevalence of IDA. Multivariate analysis confirmed that low level of mother's education (OR = 1.48; 95 CI% = 1.33-2.58; p < 0.001) was a significant predictor for IDA in these children. Conclusion: It is crucial that a comprehensive primary health care programme for these communities that includes periodic de-worming, nutrition supplement, improved household economy, education, sanitation status and personal hygiene are taken into consideration to improve the nutritional status of these children.
Notes: Ngui, Romano Lim, Yvonne Ai Lian Kin, Liam Chong Chuen, Chow Sek Jaffar, Shukri
R Ngui, Y A L Lim, R Traub, R Mahmud, M S Mistam (2012)  Epidemiological and Genetic Data Supporting the Transmission of Ancylostoma ceylanicum among Human and Domestic Animals   Plos Neglected Tropical Diseases 6: 2. 1-7 Feb  
Abstract: Background: Currently, information on species-specific hookworm infection is unavailable in Malaysia and is restricted worldwide due to limited application of molecular diagnostic tools. Given the importance of accurate identification of hookworms, this study was conducted as part of an ongoing molecular epidemiological investigation aimed at providing the first documented data on species-specific hookworm infection, associated risk factors and the role of domestic animals as reservoirs for hookworm infections in endemic communities of Malaysia. xD; xD;Methods/Findings: A total of 634 human and 105 domestic canine and feline fecal samples were randomly collected. The overall prevalence of hookworm in humans and animals determined via microscopy was 9.1% (95% CI = 7.0-11.7%) and 61.9% (95% CI = 51.2-71.2%), respectively. Multivariate analysis indicated that participants without the provision of proper latrine systems (OR = 3.5; 95% CI = 1.53-8.00; p = 0.003), walking barefooted (OR = 5.6; 95% CI = 2.91-10.73; p < 0.001) and in close contact with pets or livestock (OR = 2.9; 95% CI = 1.19-7.15; p = 0.009) were more likely to be infected with hookworms. Molecular analysis revealed that while most hookworm-positive individuals were infected with Necator americanus, Ancylostoma ceylanicum constituted 12.8% of single infections and 10.6% mixed infections with N. americanus. As for cats and dogs, 52.0% were positive for A. ceylanicum, 46.0% for Ancylostoma caninum and 2.0% for Ancylostoma braziliense and all were single infections. xD; xD;This present study provided evidence based on the combination of epidemiological, conventional diagnostic and molecular tools that A. ceylanicum infection is common and that its transmission dynamic in endemic areas in Malaysia is heightened by the close contact of human and domestic animal (i.e., dogs and cats) populations.
Notes: Ngui, Romano Lim, Yvonne A. L. Traub, Rebecca Mahmud, Rohela Mistam, Mohd Sani
R Ngui, L S Ching, T T Kai, M A Roslan, Y A L Lim (2012)  Molecular Identification of Human Hookworm Infections in Economically Disadvantaged Communities in Peninsular Malaysia   American Journal of Tropical Medicine and Hygiene 86: 5. 837-842  
Abstract: Species identification of human hookworm infections among eight communities in rural areas of Peninsular Malaysia was determined during 2009-2011. Fecal samples were examined by microscopy and subsequently, the internal transcribed spacer 2 and 28S ribosomal RNA region of Necator americanus and Ancylostoma spp. were sequenced. Overall, 9.1% (58 of 634) were identified positive by microscopy for hookworm infection, and 47 (81.0%) of 58 were successfully amplified and sequenced. Sequence comparison found that N. americanus (87.2%) was the most predominant hookworm identified, followed by Ancylostoma ceylanicum (23.4%). No A. duodenale infection was detected in this study. Detection of A. ceylanicum in humans highlighted the zoonotic transmission among humans living near dogs. Thus, implementation of effective control measures for hookworm infections in future should seriously consider this zoonotic implication.
Notes: Ngui, Romano Ching, Lee Soo Kai, Tan Tiong Roslan, Muhammad Aidil Lim, Yvonne A. L.
R Ngui, Y A L Lim, K H Chua (2012)  Rapid detection and identification of human hookworm infections through high resolution melting (HRM) analysis   PloS one 7: 7.  
Abstract: Background xD; xD;Hookworm infections are still endemic in low and middle income tropical countries with greater impact on the socioeconomic and public health of the bottom billion of the world's poorest people. In this study, a real-time polymerase chain reaction (PCR) coupled with high resolution melting-curve (HRM) analysis was evaluated for an accurate, rapid and sensitive tool for species identification focusing on the five human hookworm species. xD; xD;Methods xD; xD;Real-time PCR coupled with HRM analysis targeting the second internal transcribed spacer (ITS-2) of nuclear ribosomal DNA as the genetic marker was used to identify and distinguish hookworm species in human samples. Unique and distinct characteristics of HRM patterns were produced for each of the five hookworm species. The melting curves were characterized by peaks of 79.24±0.05°C and 83.00±0.04°C for Necator americanus, 79.12±0.10°C for Ancylostoma duodenale, 79.40±0.10°C for Ancylostoma ceylanicum, 79.63±0.05°C for Ancylostoma caninum and 79.70±0.14°C for Ancylostoma braziliense. An evaluation of the method's sensitivity and specificity revealed that this assay was able to detect as low as 0.01 ng/µl hookworm DNA and amplification was only recorded for hookworm positive samples. xD; xD;The HRM assay developed in this study is a rapid and straightforward method for the diagnosis, identification and discrimination of five human hookworms. This assay is simple compared to other probe-based genotyping methods as it does not require multiplexing, DNA sequencing or post-PCR processing. Therefore, this method offers a new alternative for rapid detection of human hookworm species.
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2011
A R Jex, Y A L Lim, J Bethony, P J Hotez, N D Young, R B Gasser (2011)  Soil-Transmitted Helminths of Humans in Southeast Asia—Towards Integrated Control   Advances in parasitology 74:  
Abstract: Soil-transmitted helminths (STHs) pose significant public health challenges in many countries of Southeast Asia (SEA). Overall, approximately one-third of the world's cases of ascariasis, trichuriasis, and hookworm disease occur in the 11 major SEA countries. Various countries are at different stages in their response to controlling these diseases. For instance, in Malaysia and Thailand, the major burden of disease is confined to rural/remote, indigenous and/or refugee populations. In countries, such as Cambodia, Lao People's Democratic Republic and Vietnam, the burden remains high, although extensive deworming programmes are underway and are yielding encouraging results. The present chapter reviews the current status of STH infections in SEA, identifies knowledge gaps and offers a perspective on the development of improved, integrated surveillance and control in this geographical region. It indicates that advances in our understanding of the epidemiology of these parasites, through the strategic use of molecular and predictive (e.g. geographical information systems (GIS) and remote sensing (RS)) technologies, could readily underpin future research and control programmes. It is hoped that the gradual move towards integrated treatment/control programmes will assist substantially in decreasing the chronic disease burden linked to STHs, thus increasing human health and welfare, and supporting socio-economic growth and development in SEA countries.
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N A Alyousefi, M A Mahdy, R Mahmud, Y A Lim (2011)  Factors associated with high prevalence of intestinal protozoan infections among patients in Sana'a City, Yemen   PLoS One 6: 7. July  
Abstract: BACKGROUND: Intestinal protozoan diseases in Yemen are a significant health problem with prevalence ranging from 18% to 27%. The present study is a cross-sectional study aimed at determining the factors associated with the high prevalence of intestinal protozoan infections among patients seeking health care in Sana'a City, the capital of Yemen. METHODOLOGY/PRINCIPAL FINDINGS: Stool samples were collected from 503 patients aged between 1 and 80 years old; 219 were males and 284 females. Biodata were collected via pretested standard questionnaire. Faecal samples were processed and examined for (oo)cysts or ova using a wet mount preparation after formal-ether concentration technique. Cryptosporidium oocysts were detected using the Ziehl-Neelsen staining technique. The overall prevalence of intestinal protozoan infections was 30.9%. Infection rates of Giardia duodenalis, Entamoeba histolytica/dispar and Cryptosporidium were 17.7%, 17.1% and 1%, respectively. Other parasites detected included Ascaris lumbricoides (2.4%), Schistosoma mansoni (0.3%), Hymenolepis nana (1.4%) and Enterobius vermicularis (0.4%). Multivariate analysis using forward stepwise logistic regression based on intestinal protozoan infections showed that contact with animals (OR = 1.748, 95% CI = 1.168-2.617) and taking bath less than twice a week (OR = 1.820, 95% CI = 1.192-2.779) were significant risk factors of protozoan infections. CONCLUSIONS/SIGNIFICANCE: This present study indicated that intestinal protozoan infections are still a public health problem in Yemen, with Giardia and Entamoeba infections being most common. Statistical analysis indicated that low personal hygiene and contact with animals were important predictors for intestinal protozoan infections. As highlighted in this study, in order to effectively reduce these infections, a multi-sectoral effort is needed. Preventive measures should include good hygienic practices, good animal husbandry practices, heightened provision of educational health programs, health services in all governorates including rural areas. Furthermore, it is also essential to find radical solutions to the recent water crises in Yemen.
Notes: Alyousefi, Naelah A xD;Mahdy, Mohammed A K xD;Mahmud, Rohela xD;Lim, Yvonne A L xD;eng xD;Research Support, Non-U.S. Gov't xD;2011/07/27 06:00 xD;PLoS One. 2011;6(7):e22044. Epub 2011 Jul 18.
Y A L Lim, A Iqbal, J Surin, B L H Sim, A R Jex, M J Nolan, H V Smith, R B Gasser (2011)  First genetic classification of Cryptosporidium and Giardia from HIV/AIDS patients in Malaysia   Infection Genetics and Evolution 11: 5. 968-974 July  
Abstract: Given the HIV epidemic in Malaysia, genetic information on opportunistic pathogens, such as Cryptosporidium and Giardia, in HIV/AIDS patients is pivotal to enhance our understanding of epidemiology, patient care, management and disease surveillance. In the present study, 122 faecal samples from HIV/AIDS patients were examined for the presence of Cryptosporidium oocysts and Giardia cysts using a conventional coproscopic approach. Such oocysts and cysts were detected in 22.1% and 5.7% of the 122 faecal samples, respectively. Genomic DNAs from selected samples were tested in a nested-PCR, targeting regions of the small subunit (SSU) of nuclear ribosomal RNA and the 60 kDa glycoprotein (gp60) genes (for Cryptosporidium), and the triose-phosphate isomerase (tpi) gene (for Giardia), followed by direct sequencing. The sequencing of amplicons derived from SSU revealed that Cryptosporidium parvum was the most frequently detected species (64% of 25 samples tested), followed by C. hominis (24%), C. meleagridis (8%) and C. felis (4%). Sequencing of a region of gp60 identified C. parvum subgenotype IIdA15G2R1 and C. hominis subgenotypes IaA14R1, IbA10G2R2, IdA15R2, IeA11G2T3R1 and IfA11G1R2. Sequencing of amplicons derived from tpi revealed G. duodenalis assemblage A, which is of zoonotic importance. This is the first report of C hominis, C. meleagridis and C. felis from Malaysian HIV/AIDS patients. Future work should focus on an extensive analysis of Cryptosporidium and Giardia in such patients as well as in domestic and wild animals, in order to improve the understanding of transmission patterns and dynamics in Malaysia. It would also be particularly interesting to establish the relationship among clinical manifestation, CD4 cell counts and genotypes/subgenotypes of Cryptosporidium and Giardia in HIV/AIDS patients. Such insights would assist in a better management of clinical disease in immuno-deficient patients as well as improved preventive and control strategies. (C) 2011 Elsevier B.V. All rights reserved.
Notes: Lim, Yvonne A. L. Iqbal, Asma Surin, Johari Sim, Benedict L. H. Jex, Aaron R. Nolan, Matthew J. Smith, Huw V. Gasser, Robin B.
L Asma, S Johari, B L H Sim, Y A L Lim (2011)  How common is intestinal parasitism in HIV-infected patients in Malaysia?   Tropical Biomedicine 28: 2. 400-410 August  
Abstract: Human immunodeficiency virus (HIV)-infected individuals have greater susceptibility to infections by a myriad of microorganisms which can cause significant morbidity and mortality compared to immunocompetent individuals. Of these microbial infections, intestinal parasitic infections (IPIs) however are receiving less attention than bacterial and viral infections, hence, the lack of information of parasitic infections in HIV individuals. Prevalence of IPIs among 346 HIV-infected individuals in Malaysia was determined in this study. The overall prevalence of intestinal parasitic infections (IPIs) was 37.9% (131 of 346) with protozoa infections (18.8%) being more common compared to helminth infections (7.5%). Observed protozoa include Entamoeba histolytica/dispar (16.8%), Cryptosporidium parvum (12.4%), Isospora, belli (10.1%), Cyclospora cayetanensis (4.9%) and Giardia duodenalis (intestinalis) (3.2%) whilst helminthes which were detected comprised of Ascaris lumbricoides (13.9%), Trichuris trichiura (6.4%) and hookworms (0.6%). Among those 131 infected, 50.4% had multiple infections and 48.9% had single parasitic infection. The CD4 counts were significantly lower (i.e., 200 cells/mm(3)) in patients harbouring IPIs. Of those individuals infected with intestinal parasites, 49% were intravenous drug users and 58% were not on any antiretroviral therapy. Most were asymptomatic and had concurrent opportunistic infections (OIs) mainly with Mycobacterium tuberculosis infection. These results confirmed that IPIs are ubiquitous among HIV-infected individuals, especially those presenting with low CD4 T cells counts, and provide useful insights into the epidemiology of these infections among HIV-infected patients in Malaysia. It is therefore recommended, that diagnosis of these intestinal parasitic pathogens should be conducted on a routine basis for better management of gastrointestinal illnesses among HIV individuals.
Notes: Asma, L. Johari, S. Sim, Benedict L. H. Lim, Yvonne A. L.
R Ngui, Y A L Lim, N F H Amir, V Nissapatorn, R Mahmud (2011)  Seroprevalence and Sources of Toxoplasmosis among Orang Asli (Indigenous) Communities in Peninsular Malaysia   American Journal of Tropical Medicine and Hygiene 85: 4. 660-666 Oct  
Abstract: This study aims to evaluate the current seroprevalence of toxoplasmosis among indigenous communities in Peninsular Malaysia and relate its association with epidemiological data. Overall seroprevalence of Toxoplasma gondii was 37.0% with 31.0% immunoglobulin (Ig) G, 1.8% IgM, and 4.2% seropositivity for both anti-Toxoplasma antibodies. Multivariate analysis showed that age above 12 years (odds ratio [OR] = 2.70, 95% confidence interval [CI] = 1.75-4.04, P < 0.001), using untreated river and mountain water supplies (OR = 1.50,95% CI = 1.01-2.40, P = 0.050), and close proximity with cats (OR = 1.40, 95% CI = 1.10-1.76, P = 0.010) were factors associated with toxoplasmosis. Given the high seroprevalence of toxoplasmosis among these communities who live in poor socioeconomic conditions, a comprehensive health surveillance program and screening should be initiated among women of childbearing age and pregnant women during the antenatal period for early diagnosis and treatment. The role of domestic cats and environmental contamination with oocyst in soil and water has to be highlighted and addressed in future prevention strategies for these communities.
Notes: Romano Ngui Lim, Yvonne A. L. Amir, Noor Farah Hani Nissapatorn, Veeranoot Mahmud, Rohela
A Sejdini, R Mahmud, Y A L Lim, M Mahdy, F Sejdini, V Gjoni, K Xhaferraj, G Kasmi (2011)  Intestinal parasitic infections among children in central Albania   Annals of Tropical Medicine and Parasitology 105: 3. 241-250 Apr  
Abstract: Although intestinal parasitic infections (IPI) among children remain a global issue, the current information on such infections in Albanian children is very limited. A cross-sectional study of the IPI in 321 children living in the Albanian counties of Tirana (152) and Elbasan (169) was therefore conducted in 2008, with a pre-tested standard questionnaire employed to gather the relevant personal and clinical data. Using formalin-ether concentration and permanent stains, stool samples were examined microscopically for the ova, cysts and oocysts of any parasites. The overall prevalence of IPI was 19% (61 of 321), with protozoan infections (11.5%) apparently more common than infections with soil-transmitted helminths (STH; 8.1%). Giardia duodenalis was the parasite most frequently detected (10.9%), followed by hookworm (5.6%), Ascaris lumbricoides (1.9%), Trichuris trichiura (0.6%), Cryptosporidium (0.3%) and Entamoeba histolytica/dispar (0.3%). The results of a univariate analysis indicated that the children from Tirana county were significantly more likely to be found infected with STH compared with the children from Elbasan county (12.5% v. 4.1%; P=0.006). Children sampled in the community were also more likely to be found STH-positive than the children sampled as they attended hospitals and health clinics (10.5% v. 6.0%) but this difference did not reach statistical significance. The children found STH-positive were five times more likely to be suffering from diarrhoea than the other children checked in clinical settings (P=0.004) and were also more likely to be suffering from abdominal pain (P=0.054) and/or diminished appetite (P=0.016).
Notes: Sejdini, A xD;Mahmud, R xD;Lim, Y A L xD;Mahdy, M xD;Sejdini, F xD;Gjoni, V xD;Xhaferraj, K xD;Kasmi, G xD;eng xD;Research Support, Non-U.S. Gov't xD;England xD;2011/08/02 06:00 xD;Ann Trop Med Parasitol. 2011 Apr;105(3):241-50.
R Ngui, S Ishak, C S Chuen, R Mahmud, Y A L Lim (2011)  Prevalence and Risk Factors of Intestinal Parasitism in Rural and Remote West Malaysia   Plos Neglected Tropical Diseases 5: 3. March  
Abstract: Background: Intestinal parasitic infections (IPIs) have a worldwide distribution and have been identified as one of the most significant causes of illnesses and diseases among the disadvantaged population. In Malaysia, IPIs still persist in some rural areas, and this study was conducted to determine the current epidemiological status and to identify risk factors associated with IPIs among communities residing in rural and remote areas of West Malaysia. Methods/Findings: A total of 716 participants from 8 villages were involved, comprising those from 1 to 83 years old, 550 (76.8%) participants aged <= 12 years and 166 (23.2%) aged >= 13 years, and 304 (42.5%) male and 412 (57.5%) female. The overall prevalence of IPIs was high (73.2%). Soil-transmitted helminth (STH) infections (73.2%) were significantly more common compared to protozoa infections (21.4%) (p<0.001). The prevalence of IPIs showed an age dependency relationship, with significantly higher rates observed among those aged <= 12 years. Multivariate analysis demonstrated that participants aged <= 12 years (OR = 2.23; 95% CI = 1.45-3.45), low household income (OR = 4.93; 95% CI = 3.15-7.73), using untreated water supply (OR = 2.08; 95% CI = 1.36-3.21), and indiscriminate defecation (OR = 5.01; 95% CI = 3.30-7.62) were identified as significant predictors of IPIs among these communities. Conclusion: Essentially, these findings highlighted that IPIs are highly prevalent among the poor rural communities in West Malaysia. Poverty and low socioeconomic with poor environmental sanitation were indicated as important predictors of IPIs. Effective poverty reduction programmes, promotion of deworming, and mass campaigns to heighten awareness on health and hygiene are urgently needed to reduce IPIs.
Notes: Ngui, Romano Ishak, Saidon Chuen, Chow Sek Mahmud, Rohela Lim, Yvonne A. L.
J X Quah, S Ambu, Y A L Lim, M A K Mahdy, J W Mak (2011)  Molecular identification of Cryptosporidium parvum from avian hosts   Parasitology 138: 5. 573-577 Apr  
Abstract: Cryptosporidium species are protozoan parasites that infect humans and a wide variety of animals. This study was aimed at identifying Cryptosporidium species and genotypes isolated from avian hosts. A total of 90 samples from 37 different species of birds were collected throughout a 3-month period from April 2008 to June 2008 in the National Zoo of Kuala Lumpur, Malaysia. Prior to molecular characterization, all samples were screened for Cryptosporidium using a modified Ziehl-Neelsen staining technique. Subsequently samples were analysed with nested-PCR targeting the partial SSU rRNA gene. Amplicons were sequenced in both directions and used for phylogenetic analysis using Neighbour-Joining and Maximum Parsimony methods. Although 9 (10%) samples were positive for Cryptosporidium via microscopy, 8 (8.9%) produced amplicons using nested PCR. Phylogenetic trees identified all the isolates as Cryptosporidium parvum. Although C. parvum has not been reported to cause infection in birds, and the role of birds in this study was postulated mainly as mechanical transporters, these present findings highlight the significant public health risk posed by birds that harbour the zoonotic species of Cryptosporidium.
Notes: Quah, J. X. Ambu, S. Lim, Y. A. L. Mahdy, M. A. K. Mak, J. W.
R Ngui, Y A L Lim, S C Chow, J A de Bruyne, C K Liam (2011)  Prevalence of Bronchial Asthma Among Orang Asli in Peninsular Malaysia   Med J Malaysia 66: 1. March  
Abstract: A survey was carried out to determine the prevalence of bronchial asthma and their contributing risk factors among Orang Asli subgroups living in Malaysia using IUATLD questionnaire and spirometry without being discriminatory towards age or gender. Of the 1171 distributed questionnaires, 716 (61.1%) comprising of 62.7% Semai Pahang, 51.3% Temiar, 74.2% Mah Meri, 65.6% Semai Perak, 53.6% Temuan, 53.8% Semelai, 61.1% Jakun and 67.4% Orang Kuala subgroups completed their questionnaire and were included in the data analysis. Participants comprised 549 (76.7%) children and 167 (23.3%) adults, age between 1 to 83 years old, 304 (42.5%) males and 412 (57.5%) females. The overall prevalence of bronchial asthma was 1.4% of which 1.5% was children, 1.3% adults, 1.0% male and 1.7% female, respectively. Of the 8 subgroups surveyed, 5 out of 10 confirmed asthma cases were Semai Pahang, followed by 3 cases among Mah Meri, and one case each among Temuan and Semai Perak subgroups, respectively. This study also demonstrated that the prevalence of self-reported and confirmed bronchial asthma tend to be higher among those who had close contact with pets, smoking individuals and among those who had a family history of asthma.
Notes:
2010
Y A L Lim, A R Jex, H V Smith, R B Gasser (2010)  Cryptosporidiosis in Southeast Asia : What's out There?   Advances in Parasitology 71: 1-31  
Abstract: Cryptosporidiosis is a socioeconomically important, enteric disease caused by a group of protozoan parasites of the genus Cryptosporidium. The significant morbidity and mortality in animals and humans caused by this disease as well as its considerable impact on the water industry have made its prevention and control a global challenge, particularly given that there are presently no widespread, affordable or effective treatment or vaccination strategies. Although much is known about Cryptosporidium and the impact of cryptosporidiosis and other diarrhoeal diseases in developed countries, this is not the case for many developing countries in Africa, South America and Asia. In Southeast Asia, which represents an epicentre for emerging infectious diseases, cryptosporidiosis has been reported in countries, such as Cambodia, Indonesia, Laos, Malaysia, Myanmar, the Philippines, Singapore, Thailand and Vietnam. In most of these countries, the likely predisposing factors for cryptosporidiosis include rapid population growth and expanding urbanisation (which are often linked to inadequate municipal water supplies and poorly managed refuse disposal) as well as the tropical climate and the increasing prevalence of HIV/AIDS and other infectious diseases. Given the close proximity of these countries and the extent of migration within and among them, cryptosporidiosis can be difficult to control. National and regional surveillance is central to preventing and controlling cryptosporidiosis. To date, most studies of cryptosporidiosis in Southeast Asia have focus on estimating the prevalence of infection in humans and animals using conventional diagnostic techniques. Future investigations using reliable molecular tools should enable improved insights into the epidemiology, systematics and population genetics of Cryptosporidium in this region. An enhanced understanding of the transmission of cryptosporidial infections and the significance of environmental contamination will require a multidisciplinary approach, built on shared resources. Such an integrated approach would underpin stable and powerful partnerships in efforts to prevent and control this disease. The purpose of the present chapter is to review available data and information on cryptosporidiosis in Southeast Asia and to provide recommendations in the pursuit of a better understanding of Cryptosporidium in this region, in order to facilitate the development of effective multidisciplinary interventions to control cryptosporidiosis.
Notes:
Y A Lim, R Mahmud, T T C H Chew, K H Chua (2010)  Plasmodium ovale infection in Malaysia : first imported case   Malar J 9: 1.  
Abstract: BACKGROUND: Plasmodium ovale infection is rarely reported in Malaysia. This is the first imported case of P. ovale infection in Malaysia which was initially misdiagnosed as Plasmodium vivax. xD; xD;METHODS: Peripheral blood sample was first examined by Giemsa-stained microscopy examination and further confirmed using a patented in-house multiplex PCR followed by sequencing. RESULTS AND DISCUSSION: Initial results from peripheral blood smear examination diagnosed P. vivax infection. However further analysis using a patented in-house multiplex PCR followed by sequencing confirmed the presence of P. ovale. Given that Anopheles maculatus and Anopheles dirus, vectors of P. ovale are found in Malaysia, this finding has significant implication on Malaysia's public health sector. xD; xD;The current finding should serve as an alert to epidemiologists, clinicians and laboratory technicians in the possibility of finding P. ovale in Malaysia. P. ovale should be considered in the differential diagnosis of imported malaria cases in Malaysia due to the exponential increase in the number of visitors from P. ovale endemic regions and the long latent period of P. ovale. It is also timely that conventional diagnosis of malaria via microscopy should be coupled with more advanced molecular tools for effective diagnosis.
Notes: Lim, Yvonne A L xD;Mahmud, Rohela xD;Chew, Ching Hoong xD;T, Thiruventhiran xD;Chua, Kek Heng xD;eng xD;Case Reports xD;Research Support, Non-U.S. Gov't xD;England xD;2010/10/12 06:00 xD;Malar J. 2010 Oct 8;9:272.
M A Mahdy, H M Al-Mekhlafi, A M Al-Mekhlafi, Y A Lim, N O Bin Shuaib, A A Azazy, R Mahmud (2010)  Molecular characterization of Leishmania species isolated from cutaneous leishmaniasis in Yemen   PLoS One 5: 9. September  
Abstract: Background xD; xD;Cutaneous leishmaniasis (CL) is a neglected tropical disease endemic in the tropics and subtropics with a global yearly incidence of 1.5 million. Although CL is the most common form of leishmaniasis, which is responsible for 60% of DALYs lost due to tropical-cluster diseases prevalent in Yemen, available information is very limited. xD; xD;Methodology/Principal Findings xD; xD;This study was conducted to determine the molecular characterization of Leishmania species isolated from human cutaneous lesions in Yemen. Dermal scrapes were collected and examined for Leishmania amastigotes using the Giemsa staining technique. Amplification of the ribosomal internal transcribed spacer 1(ITS-1) gene was carried out using nested PCR and subsequent sequencing. The sequences from Leishmania isolates were subjected to phylogenetic analysis using the neighbor-joining and maximum parsimony methods. The trees identified Leishmania tropica from 16 isolates which were represented by two sequence types. xD; xD;The predominance of the anthroponotic species (i.e. L. tropica) indicates the probability of anthroponotic transmission of cutaneous leishmaniasis in Yemen. These findings will help public health authorities to build an effective control strategy taking into consideration personâto-person transmission as the main dynamic of transmission of CL.
Notes: Mahdy, Mohammed A K xD;Al-Mekhlafi, Hesham M xD;Al-Mekhlafi, Abdulsalam M xD;Lim, Yvonne A L xD;Bin Shuaib, Naemah O M xD;Azazy, Ahmed A xD;Mahmud, Rohela xD;eng xD;2010/09/24 06:00 xD;PLoS One. 2010 Sep 20;5(9). pii: e12879.
N Romano, M O N Azah, N Rahmah, Y A L Lim, M Rohela (2010)  Seroprevalence of toxocariasis among Orang Asli (Indigenous people) in Malaysia using two immunoassays   Tropical Biomedicine 27: 3. 585-594 Dec  
Abstract: Toxocariasis is a zoonotic helminthic infection of humans caused by the dog roundworm (Toxocara canis) or cat roundworm (Toxocara cati). There are two main human syndromes: visceral larva migrans (VLM), which are characterized by symptoms associated with major organs and ocular larva migrans (OLM), in which pathological effects on the host are restricted to the eye and the optic nerve. The present study evaluated the seroprevalence of toxocariasis among the Orang Asli with an IgG4-ELISA using recombinant antigens (rTES-26, rTES-30 and rTES-120) and an IgG-ELISA commercial kit (Cypress Diagnostic, Belgium). A total of 188 serum samples were analyzed using IgG4-ELISA recombinant antigens while 83 were tested using IgG-ELISA. Overall, 9 out of 188 (4.8%) samples were positive with the former assay: rTES-26 (2.7%) and rTES-30 (2.1%); and 63 out of 83 (75.9%) were positive with the IgG-ELISA. In general, the seroprevalence of toxocariasis among males (9.5%) was higher compared to females (1%). Children below 12 years (6.3%) have higher seroprevalence rate compared to adults (1.2%). Out of 59 IgG positive samples, 56 (94.9%) were also positive with soil-transmitted helminth (STH) infections which may indicate high false positivity. None of the IgG4-ELISA positive samples were positive with STH infections. Of 9 positive samples with IgG4-ELISA, 7 were also positive with IgG-ELISA giving the probability of true cases. The present finding indicated that exposure to Toxocara infection is not unusual among Malaysian aborigines, and it affects both sexes and all age groups. As a prevention strategy, more effective public health programmes to promote better understanding on the consequences of toxocariasis among the Orang Asli communities are deemed necessary.
Notes: 723YF xD;Times Cited:1 xD;Cited References Count:31
2009
Y A L Lim, S D Ramasame, M A K Mahdy, W Y W Sulaiman, H V Smith (2009)  Detection and molecular characterization of Giardia isolated from recreational lake water in Malaysia   Parasitology Research 106: 1. 289-291 Dec  
Abstract: Nine 50-l surface water samples from a Malaysian recreational lake were examined microscopically using an immunomagnetisable separation-immunofluorescent method. No Cryptosporidium oocysts were detected, but 77.8% of samples contained low numbers of Giardia cysts (range, 0.17-1.1 cysts/l), which were genetically characterised by SSU rRNA gene sequencing. Genotype analyses indicated the presence of Giardia duodenalis assemblage A suggesting potential risk to public health. The present study represents the first contribution to our knowledge of G. duodenalis assemblages in Malaysian recreational water.
Notes: Lim, Yvonne A L xD;Ramasame, Sharmila D xD;Mahdy, Mohammed A K xD;Sulaiman, Wan Yusoff W xD;Smith, Huw V xD;eng xD;Germany xD;2009/08/26 09:00 xD;Parasitol Res. 2009 Dec;106(1):289-91.
Y A L Lim, N Romano, N Colin, S C Chow, H V Smith (2009)  Intestinal parasitic infections amongst Orang Asli (indigenous) in Malaysia : Has socioeconomic development alleviated the problem?   Tropical Biomedicine 26: 2. 110-122 August  
Abstract: Orang Asli are the indigenous minority peoples of peninsular Malaysia. Despite proactive socioeconomic development initiated by the Malaysian Government in upgrading the quality of life of the Orang Asli communities since 1978, they still remained poor with a current poverty rate of 76.9%. Poverty exacerbates the health problems faced by these communities which include malnourishment, high incidences of infectious diseases (eg. tuberculosis, leprosy, malaria) and the perpetual problem with intestinal parasitic infections. Studies reported that the mean infection rate of intestinal parasitic infections in Orang Asli communities has reduced from 91.1% in 1978, to 64.1% in the subsequent years. Although the results was encouraging, it has to be interpreted with caution because nearly 80% of studies carried out after 1978 still reported high prevalence (i.e. >50%) of soil-transmitted helminthiases (STH) among Orang Asli communities. Prior to 1978, hookworm infection is the most predominant STH but today, trichuriasis is the most common STH infections. The risk factors for intestinal parasitic infections remained unchanged and studies conducted in recent years suggested that severe STH infections contributed to malnutrition, iron deficiency anaemia and low serum retinol in Orang Asli communities. In addition, STH may also contribute to poor cognitive functions and learning ability Improvements in socioeconomic status in Malaysia have shown positive impact on the reduction of intestinal parasitic infections in other communities however, this positive impact is less significant in the Orang Asli communities. In view of this, a national parasitic infections baseline data on morbidity and mortality in the 18 subgroups of Orang Asli, will assist in identifying intervention programmes required by these communities. It is hope that the adoption of strategies highlighted in the World Health Organisation-Healthy Village Initiatives (WHO-HVI) into Orang Asli communities will ensure the whole mechanism of delivery and empowerment by the government agencies become more efficient and productive in alleviating intestinal parasitic infections in these communities.
Notes: 498AD xD;Times Cited:11 xD;Cited References Count:64
Y A Lim, M M Lai, M A Mahdy, H R Mat Naim, H V Smith (2009)  Molecular detection of Giardia contamination in water bodies in a zoo   Environ Res 109: 7. 857-9 Oct  
Abstract: We used a combined microscopy-molecular approach to determine the occurrence and identities of waterborne Giardia sp. cysts isolated from 18 separate, 10l grab samples collected from a Malaysian zoo. Microscopy revealed that 17 of 18 samples were Giardia cyst positive with concentrations ranging from 1 to 120 cysts/l. Nine (52.9%) of the 17 cyst positive samples produced amplicons of which 7 (77.8%) could be sequenced. Giardia duodenalis assemblage A (6 of 7) and assemblage B (1 of 7), both infectious to humans, were identified at all sampling sites at the zoo. The presence of human infectious cysts raises public health issues, and their occurrence, abundance and sources should be investigated further. In this zoo setting, our data highlight the importance of incorporating environmental sampling (monitoring) in addition to routine faecal examinations to determine veterinary and public health risks, and water monitoring should be considered for inclusion as a separate element in hazard analysis, as it often has a historical (accumulative) connotation.
Notes: Lim, Yvonne A L xD;Lai, Monica M xD;Mahdy, Mohammed A K xD;Mat Naim, H R xD;Smith, Huw V xD;eng xD;Research Support, Non-U.S. Gov't xD;2009/08/12 09:00 xD;Environ Res. 2009 Oct;109(7):857-9. Epub 2009 Aug 6.
A K Mahdy, J Surin, A Mohd-Adnan, K L Wan, Y A Lim (2009)  Molecular characterization of Giardia duodenalis isolated from Semai Pahang Orang Asli (Peninsular Malaysia aborigines)   Parasitology 136: 11. 1237-41 September  
Abstract: This study was conducted to determine the genotypes of Giardia duodenalis isolated from human faecal samples at Pos Betau, Pahang, Malaysia. Faecal specimens were collected and examined for G. duodenalis cysts using Trichrome staining techniques. Molecular identification was carried out by the amplification of a region of the small subunit of the nuclear ribosomal RNA (SSU rRNA) gene using nested PCR and subsequent sequencing. The sequences from 15 isolates from G. duodenalis were subjected to phylogenetic analysis (including appropriate outgroups) using the neighbor-joining and maximum parsimony methods. The trees identified G. duodenalis assemblages A and B, with a predominance of assemblage B. The predominance of anthroponotic genotypes indicates the possibility of anthroponotic transmission of these protozoa in this Semai Pahang Orang Asli community.
Notes: Mahdy, A K Mohammed xD;Surin, Johari xD;Mohd-Adnan, A xD;Wan, K-L xD;Lim, Y A L xD;eng xD;Research Support, Non-U.S. Gov't xD;England xD;2009/08/08 09:00 xD;Parasitology. 2009 Sep;136(11):1237-41. Epub 2009 Aug 7.
A K Mohammed Mahdy, J Surin, K L Wan, A Mohd-Adnan, M S Al-Mekhlafi, Y A Lim (2009)  Giardia intestinalis genotypes : Risk factors and correlation with clinical symptoms   Acta Trop 112: 1. 67-70 Oct  
Abstract: This study was conducted to identify genotypes related risk factors of Giardia intestinalis in an Orang Asli (aboriginal) community in Pahang, Malaysia. Stool samples were collected from 321 individuals aged between 2 and 76 years old, of whom 160 were males and 161 were females. Faecal samples were processed with trichrome staining technique for the primary identification of G. intestinalis. Molecular identification was carried out by the amplification of a partial SSU rRNA gene using nested PCR. PCR products were purified and genotyped. 42 samples successfully amplified from the 76 positive faecal samples, only 1 was Assemblage A, the rest were Assemblage B. Risk analysis based on the detected genotypes of Giardia using univariate analysis and logistic regression identified three significant risk factors of giardiasis caused by assemblage B which included children </=12 years (OR=13.56, 95% CI=1.79-102.64, p=0.012), females (OR=2.52, 95% CI=1.11-5.75, p=0.027) and eating fresh fruits (OR=7.78, 95% CI=1.01-60.00, p=0.049). Assemblage B infection was significantly correlated with clinical symptoms of giardiasis (OR=2.4, 95% CI=1.13-5.12, p=0.019). Females infected with Assemblage B were at higher risk of manifesting gastroenteritis signs and symptoms (OR=3.9, 95% CI=1.50-10.31, p=0.004). It has been concluded that giardiasis is still a public health problem in Orang Asli community and most commonly caused by assemblage B. The dynamic of transmission is most probably anthroponotic which is human to human either directly or indirectly through contaminated food. This route of transmission should be considered in the control strategy of the disease. Mass treatment together with health education could be the most practical intervention for reducing the infection. Those at high risk should receive more attention from public health authorities.
Notes: Mohammed Mahdy, A K xD;Surin, Johari xD;Wan, K L xD;Mohd-Adnan, A xD;Al-Mekhlafi, M S Hesham xD;Lim, Y A L xD;eng xD;Research Support, Non-U.S. Gov't xD;Netherlands xD;2009/06/30 09:00 xD;Acta Trop. 2009 Oct;112(1):67-70. Epub 2009 Jun 26.
2008
Y A L Lim, R A Ahmad, H V Smith (2008)  Current status and future trends in Cryptosporidium and Giardia epidemiology in Malaysia   Journal of Water and Health 6: 2. 239-254 Jun  
Abstract: Cryptosporidium and Giardia are major causes of diarrhoeal diseases of humans worldwide, and are included in the World Health Organisation's 'Neglected Diseases initiative'. Cryptosporidium and Giardia occur commonly in Malaysian human and non-human populations, but their impact on disease, morbidity and cost of illness is not known. The commonness of contributions from human (STW effluents, indiscriminate defaecation) and non-human (calving, lambing, muck spreading, slurry spraying, pasturing/grazing of domestic animals, infected wild animals) hosts indicate that many Malaysian environments, particularly water and soil, are sufficiently contaminated to act as potential vehicles for the transmission of disease. To gain insight into the morbidity and mortality caused by human cryptosporidiosis and giardiasis, they should be included into differential diagnoses, and routine laboratory testing should be performed and (as for many infectious diseases) reported to a centralised public health agency. To understand transmission routes and the significance of environmental contamination better will require further multidisciplinary approaches and shared resources, including raising national perceptions of the parasitological quality of drinking water. Here, the detection of cryptosporidium and Giardia should be an integral part of the water quality requirement. A multidisciplinary approach among public health professionals in the water industry and other relevant health- and environment-associated agencies is also required in order to determine the significance of Ctyptosporidium and Giardia contamination of Malaysian drinking water. Lastly, adoption of validated methods to determine the species, genotype and subgenotype of Cryptosporidium and Giardia present in Malaysia will assist in developing effective risk assessment, management and communication models.
Notes: Lim, Y A L xD;Ahmad, R A xD;Smith, H V xD;eng xD;Research Support, Non-U.S. Gov't xD;Review xD;England xD;2008/01/23 09:00 xD;J Water Health. 2008 Jun;6(2):239-54.
Y A L Lim, R Ngui, J Shukri, M Rohela, H R M Naim (2008)  Intestinal parasites in various animals at a zoo in Malaysia   Veterinary Parasitology 157: 1-2. 154-159 Oct  
Abstract: A survey was undertaken to investigate the prevalence of intestinal parasites from different groups of mammals housed in a zoological garden in Malaysia. A total of 197 faecal samples were collected randomly from various primates (99), hoofed mammals (70) and feline (28). It was discovered that 89.3% of feline, 54.5% of primates and 45.7% of hoofed mammals were infected with intestinal parasites. Intestinal parasites found in primates were Balantidium coli (19.2%), Cryptosporidium spp. (14.1%), hookworm (10.1%), Trichuris spp. (5.1%), Ascaris (4.0%) and Blastocystis spp. (2.0%). For hoofed mammals, hookworm had the highest prevalence (34.3%) followed by Trichuris spp. and Cryptosporidium spp. (5.7%). Meanwhile, for feline, Toxocara cati was the most prevalent (64.3%), followed by Cryptosporidium spp. (14.3%), Spirometra spp. (7.1%), and hookworm (3.6%). Animals that were infected were all asymptomatic with low parasite load. Routine monitoring of the presence of parasites in animals kept in the zoo is imperative in assisting zoo management in the formulation and implementation of preventive and control measures against the spread of infectious parasitic diseases among animals within the zoo or to humans. (C) 2008 Elsevier B.V. All rights reserved.
Notes: Lim, Y. A. L. Ngui, R. Shukri, J. Rohela, M. Naim, H. R. Mat
A K M Mahdy, Y A L Lim, J Surin, K L Wan, M S H Al-Mekhlafi (2008)  Risk factors for endemic giardiasis : highlighting the possible association of contaminated water and food   Transactions of the Royal Society of Tropical Medicine and Hygiene 102: 5. 465-470 May  
Abstract: This study was conducted to reassess the risk factors for giardiasis in communities of the Orang Asli (indigenous people) in Pahang, Malaysia. Stool samples were collected from 321 individuals (2-76 years old; 160 mates, 161 females). Data were collected via laboratory analysis of faecal samples and a pre-tested standard questionnaire. River water samples were tested for Giardia cysts and Cryptosporidium oocysts. The overall prevalence of G. intestinalis infection was 23.7%. Children <12 years old had the highest infection rate and have been identified as a high risk group (odds ratio (OR) =6.2, 95% CI 1.5-27.0, P < 0.005). The risk of getting giardiasis also appeared to be significantly associated with drinking piped water (OR= 5.1, 95% CI 0.06-0.7, P < 0.005) and eating raw vegetables (OR=2.4, 95% CI 0.2-0.6, P< 0.005). In conclusion, sociodemographic factors have always been associated with the high prevalence of Giardia infections in Malaysia. However, the present study also highlights the need to took into the possibility of other risks such as water and food transmission routes. In future, it is necessary that these two aspects be considered in control strategies. (C) 2008 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.
Notes: Mahdy, A. K. Mohammed Lim, Y. A. L. Surin, Johari Wan, K. L. Al-Mekhlafi, M. S. Hesham xD;Meeting of the Royal-Society-of-Tropical-Medicine-and-Hygiene xD;2007 xD;London, ENGLAND xD;Royal Soc Trop Med Hygiene
2007
Y L A Lian, B S L Heng, V Nissapatorn, C Lee (2007)  AIDS-defining illnesses : A comparison between before and after commencement of highly active antiretroviral therapy (HAART)   Current Hiv Research 5: 5. 484-489 September  
Abstract: Attempts to address the significant impact of HAART on medical variables on the Malaysian HIV/AIDS population have yet to be evaluated. This study aims to analyze the proportions of AIDS-defining illnesses (ADIs) before and after HAART. A retrospective study was carried out on 128 new cases of HIV infected patients who first commenced HAART in 2004 at the national HIV reference center. Before commencement of HAART, 76 clinical episodes of ADIs were recorded in 52 patients. Most common being pulmonary Mycobacterium tuberculosis (28.9%), PCP (27.6%) and disseminated and extrapulmonary Mycobacterium tuberculosis (11.8%). During HAART, 8 clinical episodes of ADIs were documented in 7 patients with a median time of onset of 10 weeks after initiation of HAART (range, 4-36 weeks). The median CD4 count at the time of the commencement of HAART for these patients was 11 cells/mm(3). ADIs reported include PCP (2 episodes), disseminated and extrapulmonary Mycobacterium tuberculosis (2 episodes), extrapulmonary cryptococcosis (1 episode), esophageal candidiasis (1 episode), recurrent pneumonia (1 episode) and disseminated or extrapulmonary histoplasmosis (1 episode). Three (37.5%) of these occurred despite a reduction of viral load by at least 2 log(10) and an increased in the CD4 cell count. In conclusion, ADIs can still present after the initiation of successful HAART especially in those with CD4 counts below 100 cells/mm(3). In Malaysia, ADIs are the major causes of HIV/AIDS associated morbidity and mortality, thus increased awareness on the management of these illnesses is warranted especially in the months following HAART.
Notes: 217NU xD;Times Cited:4 xD;Cited References Count:27
Y A L Lim, M Rohela, M M Shukri (2007)  Cryptosporidiosis among birds and bird handlers at Zoo Negara, Malaysia   Southeast Asian journal of tropical medicine and public health 38:  
Abstract: This study was carried out at the Malaysian National Zoo to ascertain, not only the current prevalence rate in the birds, but also to determine the association between cryptosporidiosis in birds and the bird handlers. A total of 116 fecal samples from 71 species of birds were collected from six different locations in Zoo Negara, and eight fecal samples from bird handlers were also sampled. xD; xD;Results showed that the prevalence of Cryptosporidium oocysts in birds and bird handlers were 3.4% and 12.5%, respectively. The birds that were positive for cryptosporidiosis were Wreathed Hornbill (Aceros undulatus) and Great Currasow (Crax rubra) from the aviary, Bushy-crested Hornbill (Anorrhinus galeritus) from the bird house, and the Common Peafowl (Pavo cristatus) from the lake. Birds at the lake showed the highest percentage (12.5%) of positivity, followed by birds at the aviary (5.4%) and the birdhouse (2.8%). Result of the present study seemed to indicate that cryptosporidiosis might be spreading to other species of birds and to other locations in the zoo, which was not previously documented. xD;This study also suggested the probable association of cryptosporidiosis among birds and their bird handlers. However, conclusions can only be drawn after the confirmation of speciation found in birds and bird handlers through molecular identification.
Notes:
M S Al-Mekhlafi, A S Atiya, Y A Lim, A K Mahdy, W A Ariffin, H C Abdullah, J Surin (2007)  An unceasing problem : soil-transmitted helminthiases in rural Malaysian communities   Southeast Asian J Trop Med Public Health 38: 6. 998-1007 Nov  
Abstract: Despite great development in socioeconomic status throughout 50 years of independence, Malaysia is still plagued with soil-transmitted helminthiases (STH). STH continue to have a significant impact on public health particularly in rural communities. In order to determine the prevalence of STH among rural Orang Asli children and to investigate the possible risk factors affecting the pattern of this prevalence, fecal samples were collected from 292 Orang Asli primary schoolchildren (145 males and 147 females) age 7-12 years, from Pos Betau, Kuala Lipis, Pahang. The samples were examined by Kato-Katz and Harada Mori techniques. Socioeconomic data were collected using pre-tested questionnaires. The overall prevalence of ascariasis, trichuriasis, and hookworm infections were 67.8, 95.5 and 13.4%, respectively. Twenty-nine point eight percent of the children had heavy trichuriasis, while 22.3% had heavy ascariasis. Sixty-seven point seven percent of the children had mixed infections. Age > 10 years (p = 0.016), no toilet in the house (p = 0.012), working mother (p = 0.040), low household income (p = 0.033), and large family size (p = 0.028) were identified as risk factors for ascariasis. Logistic regression confirmed low income, no toilet in the house and working mother as significant risk factors for ascariasis. The prevalence of STH is still very high in rural Malaysian communities. STH may also contribute to other health problems such as micronutrient deficiencies, protein-energy malnutrition and poor educational achievement. Public health personnel need to reassess current control measures and identify innovative and integrated ways in order to reduce STH significantly in rural communities.
Notes: Al-Mekhlafi, M S Hesham xD;Atiya, A S xD;Lim, Y A L xD;Mahdy, A K Mohammed xD;Ariffin, W A Wan xD;Abdullah, H Che xD;Surin, Johari xD;eng xD;Research Support, Non-U.S. Gov't xD;Thailand xD;2008/07/11 09:00 xD;Southeast Asian J Trop Med Public Health. 2007 Nov;38(6):998-1007.
V Nissapatorn, Y A L Lim, I Jamaiah, M Rohela, A K Anuar (2007)  Parasitic infection : A recurring phenomenon in Malaysia   Southeast Asian journal of tropical medicine and public health 38: 1.  
Abstract: A total of 255 patients including 179 (70.2%) of non-HIV and 76 (29.8%) HIV-infected patients xD;were recruited in this descriptive study. The subjects was significantly found to be male Chinese (157; xD;61.6% vs 74; 47.1%) followed by female Malays (98; 38.4% vs 35; 35.7%) (p<0.05). The majority xD;of subjects (124; 48.6%) were in the age group of 21-39 years, however, no statistical difference was found between the various age groups (p>0.05). Overall seroprevalence of latent Toxoplasma infection was 82/183 (44.8%) being; 3 (3.7%) positive for IgM, 74 (90.2%) for IgG, and 5 (6.1%) for IgG and IgM antibodies. The prevalence was more relatively found in the Chinese (28; 15.3%) and Malays (27;14.8%) than others (p<0.05). While, 23/76 (30.3%) of HIV-positive patients were shown Toxoplasma seropositivity. The majority of these subjects (138/181; 76.2%) were significantly asymptomatic (p = 0.000), while the others were clinically evident cases of toxoplasmosis. Of this, 37 patients were included in differential diagnosis relating to ocular diseases and only 4 patients were confirmed as having ocular toxoplasmosis. Toxoplasmic encephalitis (TE) was based on presumptive diagnosis, particularly found in 5 patients with AIDS. Seventeen patients were clinically diagnosed as having malaria being; 8 for P. vivax, 4 for P. falciparum, 3 for P. malariae, and 2 for mixed infections. All cases resolved satisfactorily after treatment with antimalarial drugs. Other important emerging parasitic diseases were also detected in these patients including amebiasis (2), blastocystosis (1), cryptosporidiosis (1), filariasis (1), and giardiasis (2) during the time of this study.
Notes:
Y A L Lim, W I Wan Hafiz, V Nissapatom (2007)  Reduction of Cryptosporidium and Giardia by sewage treatment processes   Tropical Biomedicine 24: 1. 95-104 Jun  
Abstract: Cryptosporidium and Giardia are two important pathogenic parasites that have caused many waterborne outbreaks which affected hundreds of thousands of people. Contamination from effluent discharged by sewage treatment plants have been implicated in previous waterborne outbreaks of Cryptosporidium and Giardia. This study evaluated the reduction of Cryptospotidium and Giardia (oo)cysts in two sewage treatment plants (STPA and STPB) in Malaysia which employed different treatment processes for a period of a year. Raw sewage influents and treated sewage effluents were concentrated by repeated centrifugation, subjected to sucrose density flotation and concentrated to a minimal volume depending upon the levels of contaminating debris. Cryptosporidium oocysts and Giardia cysts were enumerated using epifluorescence microscopy. The parasite concentrations in raw sewage were 18-8480 of Giardia cysts/litre and 1-80 of Cryptosporidium oocysts/litre. In treated sewage, the concentration of parasites ranged from 1-1462 cysts/litre and 20-80 oocysts/ litre for Giardia and Cryptosporidium respectively. Statistical analysis showed that sewage treatment process which employed extended aeration could reduce the concentration of Cryptosporidium and Giardia (oo)cysts significantly but treatment process which encompasses aerated lagoon could only reduce the concentration of Giardia cysts but not Cryptosporidium oocysts significantly. This phenomenon is of great concern in areas whereby effluent of sewage treatment plants is discharged into the upstream of rivers that are eventually used for abstraction of drinking water. Therefore, it is important that wastewater treatment authorities rethink the relevance of Cryptosporidium and Giardia contamination levels in wastewater and watersheds and to develop countermeasures in wastewater treatment plants. Further epidemiological studies on the occurrence and removal of pathogenic organisms from excreta and sewage are also recommended, in order that the public health risks can be defined and the most cost effective sewage treatment options developed.
Notes: Lim, Y A L xD;Wan Hafiz, W I xD;Nissapatorn, V xD;eng xD;Malaysia xD;2007/06/15 09:00 xD;Trop Biomed. 2007 Jun;24(1):95-104.
V Nissapatorn, Y A L Lim, I Jamaiah, H Man Chin, M Z Ilyana, M Z Nonaziah, A Siti Hasifah, I Kuppusamy (2007)  Tuberculosis in Malaysia : a continuing surge   Southeast Asian journal of tropical medicine and public health 38:  
Abstract: The substantial influx of foreign-born persons including immigrant population into the community becomes one of the postulated reasons to be elucidated relating to this so-called âa disease without borderâ in Malaysia. A total of 425 TB patients, including Malaysians and foreigners, were treated at the Institute of Respiratory Medicine from May to December 2003. TB was found relatively more often in foreign laborers and Malaysians with nonspecific occupations. Tuberculin skin test (TST) was used to screen for latent TB infection and a higher positive rate of TST was found in foreign compared to local patients. Chest X-ray findings showed a higher rate of abnormalities consistent with PTB, found in the majority of both groups. xD; xD;Lymph node biopsy and sputum culture were used significantly to detect the presence of M. tuberculosis and confirm the diagnosis of TB. EHRZ+B6 was significantly the most commonly used anti-tubercular drug regimen, found in both local and foreign patients. Foreign patients were more significantly associated with non-compliance to anti-tubercular therapy. Hepatitis was one of the most common adverse drug reactions found in local patients. The presence of a greater number of illegal migrants, who are highly mobile within the country as well as across borders, and who do not undergo any health screening, further complicates the national tuberculosis control program in the future.
Notes:
A K M Mahdy, J Surin, Y A L Lim, M S H Al-Mekhlafi (2007)  Current situation of Giardia and Cryptosporidium among Orang Asli (aboriginal) communities in Pahang, Malaysia   Southeast Asian journal of tropical medicine and public health 38:  
Abstract: A cross-sectional study on the distribution of Giardia intestinalis and Cryptosporidium species xD;was conducted among the Orang Asli communities at Pos Betau, Pahang, Malaysia. Fecal samples were collected from 316 participants, age between 1-76 years (156 males and 160 females). The samples were examined using trichrome staining technique for G. intestinalis, and Cryptosporidium species were detected using modified acid-fast staining technique. Biodata were also collected through a pre-tested standard questionnaire. The overall prevalence rates were 17.1% and 4.1%, for giardiasis and cryptosporidiosis, respectively. The study indicated that there was a significant difference in the infection rate of G. intestinalis between age groups, with infections being higher in children (p < 0.05). However, cryptosporidiosis and giardiasis were not found to be gender biased. This study concludes that giardiasis and cryptosporidiosis are still public health problems in the Orang Asli communities in Malaysia, and special attention should be given to those in the high-risk groups.
Notes:
2005
S Farizawati, Y A Lim, R A Ahmad, C Fatimah, Y Siti-Nor (2005)  Contribution of cattle farms towards river contamination with Giardia cysts and Cryptosporidium oocysts in Sungai Langat Basin   Trop. Biomed 22: 2. 89-98  
Abstract: A study to determine the contribution of Giardia cysts and Cryptosporidium xD;oocysts from cattle farms was carried out at the Langat Basin. This study investigated the xD;contribution of cattle farms, located near Sungai Langat and Sungai Semenyih, towards river xD;contamination with these cysts and oocysts. The findings showed that out of 24 samples of xD;water taken from Sungai Semenyih, 4.2% was positive for Giardia cysts with a concentration xD;of 1.3 cysts/L and 20.8% were positive with Cryptosporidium oocysts with a range of 0.7 â xD;2.7 oocysts/L. At Sungai Langat, from the 43 samples taken, 23.3% were positive for Giardia xD;cysts with a range of 1.5 â 9 cysts/L whereas 11.6% were positive with Cryptosporidium xD;oocysts with a range of 2.5 â 240 oocysts/L. Isolation of cysts and oocysts in bovine faecal xD;materials revealed that 14.6% of faecal samples were positive for Giardia cysts which had a xD;range of 75 â 1.3x10 4 cysts/g and 25% were positive for Cryptosporidium oocysts with a xD;range of 50 - 3.9x10 5 oocysts/g. From the cattle wastewater, 98% were positive with oocysts xD;and 6.7% with cysts. The concentrations were between 20 â 3.1x10 3 oocysts/mL for xD;Cryptosporidium and 4 â 75 cysts/mL for Giardia. Given that the prevalence of xD;Cryptosporidium and Giardia are high amongst the cattle and the positive findings of the xD;(oo)cysts in the river samples, it could be deduced that there is a very high possibility of the xD;cattle farms contaminating the river with Giardia cysts and Cryptosporidium oocysts. xD;Viability study of Cryptosporidium oocysts in the surrounding soil and pond within the cattle xD;farm showed that the viability of Cryptosporidium oocysts decreased with time. It was xD;estimated that it will take 52 days for all the oocysts from both environment to be non-viable. xD;With a viability rate of approximately 2 months in a cattle farm setup, river water contaminated xD;with Cryptosporidium oocysts has a high chance of acting as an agent of transmission. As xD;cattle farms are also inhabited by the owners and their families, this problem may pose a xD;threat to humans (e.g. children) especially if they are dependent on the river water as their xD;source of water for their daily activities.
Notes:
M Rohela, Y A Lim, I Jamaiah, P Y Khadijah, S T Laang, M H Nazri, Z Nurulhuda (2005)  Occurrence of Cryptosporidium oocysts in Wrinkled Hornbill and other birds in the Kuala Lumpur National Zoo   Southeast Asian J Trop Med Public Health 36 Suppl 4: 34-40  
Abstract: The occurrence of a coccidian parasite, Cryptosporidium, among birds in the Kuala Lumpur National Zoo was investigated in this study. A hundred bird fecal samples were taken from various locations of the zoo. Fecal smears prepared using direct smear and formalin ethyl acetate concentration technique were stained with modified Ziehl-Neelsen stain. Samples positive for Cryptosporidium with Ziehl-Neelsen stain were later confirmed using the immunofluorescence technique and viewed under the epifluorescence microscope. Six species of bird feces were confirmed positive with Cryptosporidium oocysts. They included Wrinkled Hornbill (Aceros corrugatus), Great Argus Pheasant (Argusianus argus), Black Swan (Cygnus atratus), Swan Goose (Anser cygnoides), Marabou Stork (Leptoptilos crumeniferus), and Moluccan Cockatoo (Cacatua moluccencis). These birds were located in the aviary and lake, with the Moluccan Cockatoo routinely used as a show bird. Results obtained in this study indicated that animal sanctuaries like zoos and bird parks are important sources of Cryptosporidium infection to humans, especially children and other animals.
Notes: Rohela, M xD;Lim, Y A L xD;Jamaiah, I xD;Khadijah, P Y Y xD;Laang, S T xD;Nazri, M H Mohd xD;Nurulhuda, Z xD;eng xD;Thailand xD;2006/01/28 09:00 xD;Southeast Asian J Trop Med Public Health. 2005;36 Suppl 4:34-40.
Y A Lim, M Rohela, B L Sim, I Jamaiah, M Nurbayah (2005)  Prevalence of cryptosporidiosis in HIV-infected patients in Kajang Hospital, Selangor   Southeast Asian J Trop Med Public Health 36 Suppl 4: 30-3  
Abstract: A total of 66 fecal specimens obtained from patients infected with human immunodeficiency virus (HIV) from Kajang Hospital were screened for Cryptosporidium oocysts. The fecal specimens were concentrated using the formalin ethyl acetate concentration technique, stained with modified Ziehl-Neelsen and confirmed with immunofluorescence stain. It was established that 2 (3.0%) were positive for Cryptosporidium. The two cases involved a Chinese local man (with diarrhea) and an Indonesian foreigner (without diarrhea). A higher index of suspicion for clinical cryptosporidiosis in HIV patients, including those with chronic weight loss with or without diarrhea, is recommended. In addition, laboratory testing for Cryptosporidium in HIV-infected patients is highly recommended in order to have a better understanding of the epidemiology and management of the disease in Malaysia.
Notes: Lim, Y A L xD;Rohela, M xD;Sim, B L H xD;Jamaiah, I xD;Nurbayah, M xD;eng xD;Thailand xD;2006/01/28 09:00 xD;Southeast Asian J Trop Med Public Health. 2005;36 Suppl 4:30-3.
2004
Y A Lim, R A Aahmad (2004)  Occurrence of Giardia cysts and Cryptosporidium oocysts in the Temuan Orang Asli (aborigine) River System   Southeast Asian J Trop Med Public Health 35: 4. 801-10 Dec  
Abstract: A survey of the river water frequently used by the Temuan Orang Asli (aborigine) indicated that 66.7% of the river water samples were Giardia cyst positive and 5.6% were Cryptosporidium oocyst positive. Although Giardia cysts were detected in samples from all the sites (e.g. upstream, midstream, and downstream), Cryptosporidium was only present in one river water sample taken from downstream from a village. The only sample of upstream water which contained Giardia cysts had a concentration of 0.7 cysts/l. All samples taken from midstream contained cysts with a mean concentration of 9.8 +/- 6.6 cysts/l (range = 1-20 cysts/l). Eighty-three point three percent of the samples collected from downstream contained cysts and 16.7% had oocysts. The average concentration of cysts was 12.9 +/- 16.4 cysts/l (range = 0-44 cysts/l), whereas the oocyst concentration was 0.4 oocysts/l. All river samples tested positive for the presence of E. coli, indicating fecal contamination. The results of this study imply that the river system is contaminated with fecal-oral transmitted parasites. The river water, used by the Orang Asli, is a probable route for Giardia and Cryptosporidium transmission in this community. Long term strategies, incorporating health education regarding personal hygiene, and provision of toilets and the importance of their proper usage, need to be embraced by this community in order to control the spread of these parasites.
Notes: Lim, Y A L xD;Aahmad, R A xD;eng xD;Research Support, Non-U.S. Gov't xD;Thailand xD;2005/05/27 09:00 xD;Southeast Asian J Trop Med Public Health. 2004 Dec;35(4):801-10.
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