Yvonne Lim Ai Lian | University of Malaya, Malaysia (original) (raw)

Papers by Yvonne Lim Ai Lian

The present study was conducted to determine the occurrence of Schistosoma spindale ova and its a... more The present study was conducted to determine the occurrence of Schistosoma spindale ova and its associated risk factors in Malaysian cattle through a coprological survey. A total of 266 rectal fecal samples were collected from six farms in Peninsular Malaysia. The overall infection rate of S. spindale was 6% (16 of 266). Schistosoma spindale infection was observed in two farms, with a prevalence of 5.4% and 51.9%, respectively. This trematode was more likely to co-occur with other gastro-intestinal parasites (i.e., Dicrocoelium spp., Paramphistomum spp., strongyle, Eimeria spp. and Entamoeba spp.). Chi-square analysis revealed that female cattle are less likely to get S. spindale infection as compared to male cattle (OR ＝ 0.3; 95% CI ＝ 0.08-1.06; p ＜ 0.05), and cattle weighing lower than 200 kg, were significantly at higher risk than those higher than 200 kg (OR ＝ 5; 95% CI ＝ 1.07-24.79; p ＜ 0.05) to the infection. Multivariate analysis confirmed that among the cattle in Malaysia, the age (cattle with two year old and higher: OR ＝ 21; 95% CI ＝ 2.48-179.44; p ＜ 0.05) and weight (weighing 200 kg and lower: OR ＝ 17; 95% CI ＝ 3.38-87.19; p ＜ 0.05

International Journal of Current Research and Review, 2021

Background: Contaminated vegetables with intestinal parasites, particularly those eaten raw, repr... more Background: Contaminated vegetables with intestinal parasites, particularly those eaten raw, represent a proportion of risks for humans acquiring foodborne parasitic diseases worldwide. Unfortunately, the risk is often neglected as limited studies have been reported about the parasitic occurrence from vegetables retailed in Malaysia. Objective: This study was conducted to determine the occurrence of intestinal parasites in fresh retailed vegetables in Kuching and Kota Samarahan, Sarawak. Methods: A total of 108 vegetables (comprising leafy and root-type vegetables) were purchased from three supermarkets and three wet markets in Kuching and Kota Samarahan. The samples were processed with 0.95% sodium chloride solution and underlaid with Sheather's sucrose solution. Cryptosporidium and Giardia were detected using AquaGlo TM G/C antibody reagent and 4′,6-diamidino-2-phenylindole stain. Other parasites were detected using Lugol's iodine stain. Results: A total of 24 out of 108 vegetables samples (22.2%) were contaminated with nematode larvae (range: 0.01-0.71 larvae/g), Cryptosporidium oocysts (range: 0.01-0.03 oocysts/g), hookworm ova (range: 0.01-0.02 ova/g) and Giardia cyst (0.01 cysts/g). There were no significant differences (p > 0.05) for means of parasite concentrations in vegetables from supermarkets and wet markets, as well as parasite concentrations from leafy-type and root-type vegetables. Conclusion: The findings revealed relatively high numbers of intestinal parasites detected from fresh retailed vegetables, signifying potential foodborne transmission of parasitic infections if the vegetables are not prepared hygienically or cooked well. Besides, a high proportion of such infection risk may be reduced if farmers also take part in proper sanitation practices during vegetable production and transportation.

Scientific Reports, 2020

Dengue has become a global public health problem. Despite reactive efforts by the government in M... more Dengue has become a global public health problem. Despite reactive efforts by the government in Malaysia, the dengue cases are on the increase. Adequate knowledge, positive attitude and correct practice for dengue control are essential to stamp out the disease. Hence, this study aims to assess the factors associated with dengue knowledge, attitude and practice (KAP), as well as the association with dengue IgM and IgG seropositivity. A community-based cross-sectional study was conducted in a closed, dengue endemic area with multi-storey dwellings . Five hundred individuals (aged 18 years and above) were approached for pre-tested KAP and seroprevalences assessment. The study showed only half of the total participants have good knowledge (50.7%) but they had insufficient knowledge about dengue during pregnancy. 53.2% of people had poor attitude and 50.2% reported poor practice for dengue control. Out of 85 respondents who agreed to participate in the dengue seroprevalence study, 74.1% ...

Pathogens and global health, Jan 24, 2017

Entamoeba histolytica infection remains a public health concern in developing countries. Early di... more Entamoeba histolytica infection remains a public health concern in developing countries. Early diagnosis of amoebiasis can avoid disease complications, thus this study was aimed at developing a test that can rapidly detect the parasite antigens in stool samples. Rabbits were individually immunized with recombinant pyruvate phosphate dikinase (rPPDK) and E. histolytica excretory-secretory antigens to produce polyclonal antibodies. A rapid dipstick test was produced using anti-rPPDK PAb lined on the dipstick as capture reagent and anti-EhESA PAb conjugated to colloidal gold as the detector reagent. Using E. histolytica-spiked in stool sample of a healthy individual, the detection limit of the dipstick test was found to be 1000 cells ml(-1). Meanwhile when rPPDK was spiked in the stool sample, the minimum concentration detected by the dipstick test was 0.1 μg ml(-1). The performances of the dipstick, commercial Techlab E. histolytica II enzyme-linked immunosorbent assays (ELISA) and re...

Tropical biomedicine, 2009

Orang Asli are the indigenous minority peoples of peninsular Malaysia. Despite proactive socioeco... more 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 predo...

The Southeast Asian journal of tropical medicine and public health, 2007

Despite great development in socioeconomic status throughout 50 years of independence, Malaysia i... more 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 ...

Tropical biomedicine, 2011

Human immunodeficiency virus (HIV)-infected individuals have greater susceptibility to infections... more 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%), Trich...

Parasites and their vectors, 2013

Southeast Asia (SEA) located between India and China is a thriving subregion of Asia blessed with... more Southeast Asia (SEA) located between India and China is a thriving subregion of Asia blessed with highly diverse flora and fauna, covering an area of approximately 4 million km, and is inhabited by approximately 600 million people. The interconnected driving forces of rapid urbanisation, exponential population growth and mobility in SEA have crucial public health implications. Given its rich biodiversity, SEA is the hotspot region for parasitic infections, in particular, zoonotic and vector-borne diseases. Hitherto, there has been no collective systematic appraisal of parasitic infections and their vectors in Southeast Asia. For these reasons, this book presents a comprehensive review of all the accessible information/data and publications for the 11 member countries of the Association of Southeast Asian Nations (ASEAN) which include Indonesia, Malaysia, Philippines, Singapore, Thailand, Brunei Darussalam, Cambodia, Lao PDR, Myanmar, Vietnam and Timor-Leste (observer). A better understanding of these infections would assist in formulating a solid scientific framework/platform for future integrated research in the field of parasitic infections. This effort may spearhead a consolidated regional effort in the field of public health and prepare the region as it launches into a borderless trade in 2015 with the establishment of the ASEAN Economic Community (AEC).

Malaria journal, Jan 8, 2010

Plasmodium ovale infection is rarely reported in Malaysia. This is the first imported case of P. ... more 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. Peripheral blood sample was first examined by Giemsa-stained microscopy examination and further confirmed using a patented in-house multiplex PCR followed by sequencing. 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. 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 th...

Transactions of the Royal Society of Tropical Medicine and Hygiene, 2008

This study was conducted to reassess the risk factors for giardiasis in communities of the Orang ... more 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 males, 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 < or =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 look 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.

PLoS ONE, 2011

Background: Intestinal protozoan diseases in Yemen are a significant health problem with prevalen... more 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.

PLoS ONE, 2012

Background: Hookworm infections are still endemic in low and middle income tropical countries wit... more Background: 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. Methods: 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 79.2460.05uC and 83.0060.04uC for Necator americanus, 79.1260.10uC for Ancylostoma duodenale, 79.4060.10uC for Ancylostoma ceylanicum, 79.6360.05uC for Ancylostoma caninum and 79.7060.14uC 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/ml hookworm DNA and amplification was only recorded for hookworm positive samples. Conclusion: 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.

PLoS ONE, 2012

Background: Currently, there is a lack of vital information in the genetic makeup of Cryptosporid... more 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.

PLoS Neglected Tropical Diseases, 2012

Background: Currently, information on species-specific hookworm infection is unavailable in Malay... more 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. 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. Conclusion: 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.

PLoS Neglected Tropical Diseases, 2013

Background: Giardia duodenalis infection and malnutrition are still considered as public health p... more Background: Giardia duodenalis infection and malnutrition are still considered as public health problems in many developing countries especially among children in rural communities. This study was carried out among Aboriginal (Orang Asli) primary schoolchildren in rural peninsular Malaysia to investigate the burden and the effects of Giardia infection on growth (weight and height) of the children. Methods/Findings: Weight and height of 374 children aged 7-12 years were assessed before and after treatment of Giardia infection. The children were screened for Giardia parasite using trichrome staining technique. Demographic and socioeconomic data were collected via face-to-face interviews using a pre-tested questionnaire. Overall, 22.2% (83/374) of the children were found to be infected with Giardia. Nutritional status of children was assessed and the results showed that the mean weight and height were 23.9 kg (95% CI = 23.3, 24.5) and 126.6 cm (95% CI = 125.6, 127.5), respectively. Overall, the prevalence of severe underweight, stunting and wasting were 28.3%, 23.8% and 21.0%, respectively. Multiple linear regression analyses showed sex, Giardia infection and household monthly income as the significant determinants of weight while sex and level of mother's education were the significant determinants of height. Weight and height were assessed at 3 and 6 months after treatment of Giardia infection. It was found that Giardia infection has a significant association with the weight of children but not with height. Conclusions/Significance: This study reveals high prevalence of Giardia infection and malnutrition among Aboriginal children in rural Malaysia and clearly highlights an urgent need to identify integrated measures to control these health problems in the rural communities. Essentially, proper attention should be given to the control of Giardia infection in Aboriginal communities as this constitutes one of the strategies to improve the nutritional status of Aboriginal children.

PLoS Neglected Tropical Diseases, 2011

Background: Intestinal parasitic infections (IPIs) have a worldwide distribution and have been id... more 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.

PLoS Neglected Tropical Diseases, 2012

Background: Given that micronutrient deficiency, neglected intestinal parasitic infections (IPIs)... more 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.

The present study was conducted to determine the occurrence of Schistosoma spindale ova and its a... more The present study was conducted to determine the occurrence of Schistosoma spindale ova and its associated risk factors in Malaysian cattle through a coprological survey. A total of 266 rectal fecal samples were collected from six farms in Peninsular Malaysia. The overall infection rate of S. spindale was 6% (16 of 266). Schistosoma spindale infection was observed in two farms, with a prevalence of 5.4% and 51.9%, respectively. This trematode was more likely to co-occur with other gastro-intestinal parasites (i.e., Dicrocoelium spp., Paramphistomum spp., strongyle, Eimeria spp. and Entamoeba spp.). Chi-square analysis revealed that female cattle are less likely to get S. spindale infection as compared to male cattle (OR ＝ 0.3; 95% CI ＝ 0.08-1.06; p ＜ 0.05), and cattle weighing lower than 200 kg, were significantly at higher risk than those higher than 200 kg (OR ＝ 5; 95% CI ＝ 1.07-24.79; p ＜ 0.05) to the infection. Multivariate analysis confirmed that among the cattle in Malaysia, the age (cattle with two year old and higher: OR ＝ 21; 95% CI ＝ 2.48-179.44; p ＜ 0.05) and weight (weighing 200 kg and lower: OR ＝ 17; 95% CI ＝ 3.38-87.19; p ＜ 0.05

International Journal of Current Research and Review, 2021

Background: Contaminated vegetables with intestinal parasites, particularly those eaten raw, repr... more Background: Contaminated vegetables with intestinal parasites, particularly those eaten raw, represent a proportion of risks for humans acquiring foodborne parasitic diseases worldwide. Unfortunately, the risk is often neglected as limited studies have been reported about the parasitic occurrence from vegetables retailed in Malaysia. Objective: This study was conducted to determine the occurrence of intestinal parasites in fresh retailed vegetables in Kuching and Kota Samarahan, Sarawak. Methods: A total of 108 vegetables (comprising leafy and root-type vegetables) were purchased from three supermarkets and three wet markets in Kuching and Kota Samarahan. The samples were processed with 0.95% sodium chloride solution and underlaid with Sheather's sucrose solution. Cryptosporidium and Giardia were detected using AquaGlo TM G/C antibody reagent and 4′,6-diamidino-2-phenylindole stain. Other parasites were detected using Lugol's iodine stain. Results: A total of 24 out of 108 vegetables samples (22.2%) were contaminated with nematode larvae (range: 0.01-0.71 larvae/g), Cryptosporidium oocysts (range: 0.01-0.03 oocysts/g), hookworm ova (range: 0.01-0.02 ova/g) and Giardia cyst (0.01 cysts/g). There were no significant differences (p > 0.05) for means of parasite concentrations in vegetables from supermarkets and wet markets, as well as parasite concentrations from leafy-type and root-type vegetables. Conclusion: The findings revealed relatively high numbers of intestinal parasites detected from fresh retailed vegetables, signifying potential foodborne transmission of parasitic infections if the vegetables are not prepared hygienically or cooked well. Besides, a high proportion of such infection risk may be reduced if farmers also take part in proper sanitation practices during vegetable production and transportation.

Scientific Reports, 2020

Dengue has become a global public health problem. Despite reactive efforts by the government in M... more Dengue has become a global public health problem. Despite reactive efforts by the government in Malaysia, the dengue cases are on the increase. Adequate knowledge, positive attitude and correct practice for dengue control are essential to stamp out the disease. Hence, this study aims to assess the factors associated with dengue knowledge, attitude and practice (KAP), as well as the association with dengue IgM and IgG seropositivity. A community-based cross-sectional study was conducted in a closed, dengue endemic area with multi-storey dwellings . Five hundred individuals (aged 18 years and above) were approached for pre-tested KAP and seroprevalences assessment. The study showed only half of the total participants have good knowledge (50.7%) but they had insufficient knowledge about dengue during pregnancy. 53.2% of people had poor attitude and 50.2% reported poor practice for dengue control. Out of 85 respondents who agreed to participate in the dengue seroprevalence study, 74.1% ...

Pathogens and global health, Jan 24, 2017

Entamoeba histolytica infection remains a public health concern in developing countries. Early di... more Entamoeba histolytica infection remains a public health concern in developing countries. Early diagnosis of amoebiasis can avoid disease complications, thus this study was aimed at developing a test that can rapidly detect the parasite antigens in stool samples. Rabbits were individually immunized with recombinant pyruvate phosphate dikinase (rPPDK) and E. histolytica excretory-secretory antigens to produce polyclonal antibodies. A rapid dipstick test was produced using anti-rPPDK PAb lined on the dipstick as capture reagent and anti-EhESA PAb conjugated to colloidal gold as the detector reagent. Using E. histolytica-spiked in stool sample of a healthy individual, the detection limit of the dipstick test was found to be 1000 cells ml(-1). Meanwhile when rPPDK was spiked in the stool sample, the minimum concentration detected by the dipstick test was 0.1 μg ml(-1). The performances of the dipstick, commercial Techlab E. histolytica II enzyme-linked immunosorbent assays (ELISA) and re...

Tropical biomedicine, 2009

Orang Asli are the indigenous minority peoples of peninsular Malaysia. Despite proactive socioeco... more 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 predo...

The Southeast Asian journal of tropical medicine and public health, 2007

Despite great development in socioeconomic status throughout 50 years of independence, Malaysia i... more 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 ...

Tropical biomedicine, 2011

Human immunodeficiency virus (HIV)-infected individuals have greater susceptibility to infections... more 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%), Trich...

Parasites and their vectors, 2013

Southeast Asia (SEA) located between India and China is a thriving subregion of Asia blessed with... more Southeast Asia (SEA) located between India and China is a thriving subregion of Asia blessed with highly diverse flora and fauna, covering an area of approximately 4 million km, and is inhabited by approximately 600 million people. The interconnected driving forces of rapid urbanisation, exponential population growth and mobility in SEA have crucial public health implications. Given its rich biodiversity, SEA is the hotspot region for parasitic infections, in particular, zoonotic and vector-borne diseases. Hitherto, there has been no collective systematic appraisal of parasitic infections and their vectors in Southeast Asia. For these reasons, this book presents a comprehensive review of all the accessible information/data and publications for the 11 member countries of the Association of Southeast Asian Nations (ASEAN) which include Indonesia, Malaysia, Philippines, Singapore, Thailand, Brunei Darussalam, Cambodia, Lao PDR, Myanmar, Vietnam and Timor-Leste (observer). A better understanding of these infections would assist in formulating a solid scientific framework/platform for future integrated research in the field of parasitic infections. This effort may spearhead a consolidated regional effort in the field of public health and prepare the region as it launches into a borderless trade in 2015 with the establishment of the ASEAN Economic Community (AEC).

Malaria journal, Jan 8, 2010

Plasmodium ovale infection is rarely reported in Malaysia. This is the first imported case of P. ... more 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. Peripheral blood sample was first examined by Giemsa-stained microscopy examination and further confirmed using a patented in-house multiplex PCR followed by sequencing. 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. 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 th...

Transactions of the Royal Society of Tropical Medicine and Hygiene, 2008

This study was conducted to reassess the risk factors for giardiasis in communities of the Orang ... more 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 males, 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 < or =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 look 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.

PLoS ONE, 2011

Background: Intestinal protozoan diseases in Yemen are a significant health problem with prevalen... more 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.

PLoS ONE, 2012

Background: Hookworm infections are still endemic in low and middle income tropical countries wit... more Background: 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. Methods: 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 79.2460.05uC and 83.0060.04uC for Necator americanus, 79.1260.10uC for Ancylostoma duodenale, 79.4060.10uC for Ancylostoma ceylanicum, 79.6360.05uC for Ancylostoma caninum and 79.7060.14uC 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/ml hookworm DNA and amplification was only recorded for hookworm positive samples. Conclusion: 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.

PLoS ONE, 2012

Background: Currently, there is a lack of vital information in the genetic makeup of Cryptosporid... more 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.

PLoS Neglected Tropical Diseases, 2012

Background: Currently, information on species-specific hookworm infection is unavailable in Malay... more 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. 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. Conclusion: 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.

PLoS Neglected Tropical Diseases, 2013

Background: Giardia duodenalis infection and malnutrition are still considered as public health p... more Background: Giardia duodenalis infection and malnutrition are still considered as public health problems in many developing countries especially among children in rural communities. This study was carried out among Aboriginal (Orang Asli) primary schoolchildren in rural peninsular Malaysia to investigate the burden and the effects of Giardia infection on growth (weight and height) of the children. Methods/Findings: Weight and height of 374 children aged 7-12 years were assessed before and after treatment of Giardia infection. The children were screened for Giardia parasite using trichrome staining technique. Demographic and socioeconomic data were collected via face-to-face interviews using a pre-tested questionnaire. Overall, 22.2% (83/374) of the children were found to be infected with Giardia. Nutritional status of children was assessed and the results showed that the mean weight and height were 23.9 kg (95% CI = 23.3, 24.5) and 126.6 cm (95% CI = 125.6, 127.5), respectively. Overall, the prevalence of severe underweight, stunting and wasting were 28.3%, 23.8% and 21.0%, respectively. Multiple linear regression analyses showed sex, Giardia infection and household monthly income as the significant determinants of weight while sex and level of mother's education were the significant determinants of height. Weight and height were assessed at 3 and 6 months after treatment of Giardia infection. It was found that Giardia infection has a significant association with the weight of children but not with height. Conclusions/Significance: This study reveals high prevalence of Giardia infection and malnutrition among Aboriginal children in rural Malaysia and clearly highlights an urgent need to identify integrated measures to control these health problems in the rural communities. Essentially, proper attention should be given to the control of Giardia infection in Aboriginal communities as this constitutes one of the strategies to improve the nutritional status of Aboriginal children.

PLoS Neglected Tropical Diseases, 2011

Background: Intestinal parasitic infections (IPIs) have a worldwide distribution and have been id... more 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.

PLoS Neglected Tropical Diseases, 2012

Background: Given that micronutrient deficiency, neglected intestinal parasitic infections (IPIs)... more 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.