Soil-transmitted helminthiasis (STH), among the most common neglected tropical diseases, is a major public health problem in Malaysia with a possible impact on the nutritional status and school participation of rural children. This study was carried out among Aboriginal schoolchildren, living in an endemic area for STH in Malaysia, to determine the possible relationship between intestinal helminthiasis and school absenteeism. We also evaluated whether successful treatment of the infection will affect school attendance among the subjects. Stool analysis revealed that more than 90% of the subjects were infected with at least 1 helminth species, with Ascaris lumbricoides and Trichuris trichiura infections being most prevalent. Infection of moderate-to-heavy worm burdens, low level of fathers' education and anaemia were identified as the significant predictors of high absenteeism among the subjects (P<0·05). Following treatment of the infected children, it was found that school absenteeism was reduced significantly (P<0·01). In conclusion, STH continues to have significant impacts on public health, particularly in rural communities with a negatively significant effect on the school participation of Aboriginal children. A school-based de-worming programme should be introduced and incorporated in the current educational assistance targeted towards the Aboriginal communities, under the auspices of the government.
This study aims to determine the prevalence of protein-energy malnutrition and its association with soil-transmitted helminthiases in Orang Asli (Aborigine) children in Selangor, Malaysia. The results obtained from 368 children aged 2-15 years showed that the overall prevalence of mild and significant underweight was 32.1% and 56.5% respectively. The prevalence of mild stunting was 25.6% while another 61.3% had significant stunting. The overall prevalence of mild and significant wasting was 39.0% and 19.5% respectively. The overall prevalence of ascariasis, trichuriasis and hookworm infection were 61.9%, 98.2% and 37.0% respectively and of these 18.9%, 23.5% and 2.5% of the children had severe infection of the respective helminthes. The overall prevalence of giardiasis was 24.9%. The present study vividly shows that stunting and underweight are highly prevalent among Orang Asli children and therefore of concern in this community. In this population intestinal parasitic infections, especially severe trichuriasis and giardiasis, were identified as the main predictors of stunting and wasting respectively, in addition to age between 2 to 6 years.
A cross-sectional study to determine the current prevalence of anaemia and iron deficiency anaemia (IDA) and to investigate the possible risk factors for IDA was carried out on 241 aboriginal schoolchildren (120 boys, 121 girls) aged 7-12 years and living in remote areas in Pos Betau, Pahang, Malaysia. Haemoglobin (Hb) level was measured and serum iron status was assessed by serum ferritin (SF), serum iron (SI) and total iron binding capacity measurements. Socioeconomic data were collected using pre-tested questionnaires. All children were screened for intestinal parasitic infections. Overall, 48.5% (95% CI 42.3-54.8) of children were anaemic (Hb<12 g/dl). The prevalence of IDA was 34% (95% CI 28.3-40.2), which accounted for 70.1% of the anaemia cases. The prevalence of IDA was significantly higher in females than males. Low levels of mothers' education and low household income were identified as risk factors for IDA. Severe trichuriasis also found to be associated with low SF and SI. Logistic regression confirmed low levels of mothers' education and gender as significant risk factors for IDA. Improvement of socioeconomic status and health education together with periodic mass deworming should be included in public health strategies for the control and prevention of anaemia and IDA in this population.
Vitamin A deficiency and malnutrition are still considered public health problems in rural areas of developing countries, including Malaysia. A cross-sectional exploration study was carried out on 281 Orang Asli (Aborigine) children aged between 2 and 15 years in Selangor, Malaysia. The overall prevalence of low serum retinol (<70 micromol/l) and hypoalbuminaemia (<35 g/l) were 25.2 and 7.8%, respectively. Univariate analysis showed that severe ascariasis, significant stunting and giardiasis were significantly associated with low concentration of serum retinol. As well as intestinal parasitic infections, low socio-economic status was a significant predictor of hypoalbuminaemia. Logistic regression analysis identified severe ascariasis and significant stunting as predictors of low serum retinol, while mixed intestinal parasitic infection and low household income were predictors of hypoalbuminaemia. In conclusion, control measures for intestinal parasitic infections should be included as one of the strategies for the prevention and control of malnutrition and vitamin A deficiency in this population.
Soil-transmitted helminthiases are a public health problem in rural communities. A cross-sectional study of the prevalence and distribution of Ascaris lumbricoides, Trichuris trichiura and hookworm was conducted in 281 Orang Asli children (aborigines) aged between 2 and 15 years, from 8 Orang Asli villages in Selangor, Malaysia. All the children were infected with soil-transmitted helminthes, with 26.3% of the children infected either with A. lumbricoides, T. trichiura or hookworm and 72.6% having mixed infection. The overall prevalences of A. lumbricoides, T. trichiura and hookworm were 61.9, 98.2 and 37.0%, respectively. Approximately 19.0, 26.0 and 3.0% of the children had severe infection of ascariasis, trichuriasis and hookworm infection, respectively. The prevalences and mean egg per gram (epg) counts for A. lumbricoides and T. trichiura were not significantly dependent on age, therefore age-dependent convexity was not seen in this study. However, the results of this study reveal an age-dependent prevalence and mean epg count in children with hookworm infection. We conclude that ascariasis, trichuriasis and hookworm infection are still prevalent and therefore a public health concern in Orang Asli communities. Severe ascariasis and trichuriasis may lead to other health and medical problems.
A cross-sectional study on helminthiasis among rural primary schoolchildren aged 9 to 10 years Bachok, Kelaritan was perfumed. A total of 680 schoolchildren participated in the study. Stool specimens were examined for the presence of the ova of Ascaris lumbricoides, Trichuris trichiura and hoolcwonn. The worm load was then measured using the modified Stoll`s volumetric dilution
technique. The overall prevalence of helminthiasis was 77 .2%. Trichuris trichiura were the commonest type of heminth noted - 66.8%, compared with Ascaris lumlrricoides (49.7%) and hookworm (1.8%). Mixed infections with Ascaris lumlyricoides and Trichuris trichiura was the commonest type of infection 249(41 .5%) . For Ascaris lumbncoides, 34.6% had mild and 5 I .3% had moderate worm load while for Trichurb trichiura, 66.5% had mild and 30.8 % had moderate worm load. Only 14.1% and 2.7% 4 of the schoolchildren had a heavy load of Ascaris lumlwicoides and Trichuris trichiura respectively. All the schookhildren with hookworm were only mildly infected. Targeted mass treatment for rural Mahysian schoolchildren is still essential, especially in areas where poverty and malnutrition are still prevalent.
Soil-transmitted helminth infections remain a major public health burden in low- and middle-income countries. The traditional diagnosis by microscopic examination of fecal samples is insensitive and time-consuming. In this study, a pentaplex real-time polymerase chain reaction (PCR) was evaluated for the simultaneous detection of Ancylostoma, Necator americanus, Ascaris lumbricoides, and Strongyloides stercoralis. The results were compared with those obtained by conventional parasitological diagnostic methods. Real-time PCR was positive in 48 of 77 samples (62.3%) and microscopic examination was positive in six samples (7.8%) only (P < 0.05). In conclusion, the real-time PCR assay described in this study provides a specific and sensitive diagnostic tool for the detection of these four helminth species in epidemiological studies and monitoring of treatment programs.
The gastrointestinal helminth infection status of 1574 children living in a slum area of Kuala Lumpur, Malaysia was assessed by quantitative coprology. Almost two-thirds were infected with Trichuris trichiura, 49.6% with Ascaris lumbricoides, and 5.3% with hookworm. Infection prevalence rose rapidly to a stable asymptote at 7 years of age, and the age-intensity profile was convex with maximal values in the 5-10 year age classes. This pattern was the same for males and females, but differed markedly between different ethnic groups. The frequency distributions of A. lumbricoides and T. trichiura were highly overdispersed (k values were 0.21 and 0.27, respectively), and age-dependent over the 0-8 year age classes. This suggests that the force of infection with these nematodes is lower in infants than in older children.
This study examines the persistence of familial aggregation and familial predisposition to Ascaris lumbricoides and Trichuris trichiura infection over 2 periods of treatment and reinfection, in an urban community in Kuala Lumpur, Malaysia. Both parasite species were shown to be aggregated (assessed by the variance to mean ratio) within families at all 3 interventions, although no consistent trend in aggregation was observed over the period of the study. Associations between mean A. lumbricoides and T. trichiura infection levels of families, at all 3 interventions, were highly significant (P < 0.0001), suggesting persistent predisposition at the family level.
This study examines the persistence of predisposition to Ascaris lumbricoides and Trichuris trichiura during repeated chemotherapy in an urban community in Kuala Lumpur, Malaysia. Significant predisposition was observed over 2 periods of reinfection with and without age-standardization of data. Analysis of different age groups indicated that predisposition was most strongly detectable in the younger age classes. The intensities of infection with both parasites were strongly correlated at each cycle of intervention, suggesting that individuals were similarly predisposed to both species.
The prevalence and intensity of intestinal nematode infections were assessed during 3 anthelminthic interventions in an urban community in Malaysia. The prevalence levels of Ascaris lumbricoides at Interventions 1, 2 and 3 were 30.6%, 18.9% and 15.5%, respectively and the mean intensities were 1.9, 0.75 and 0.81 worms per person. For Trichuris trichiura, the prevalence levels at Interventions 1, 2 and 3 were 46.9%, 21.6% and 15.7%, respectively. The mean intensities for T. trichiura at Interventions 1, 2 and 3 were 3.30, 0.92 and 0.07 worms per person. No gender-related prevalence and intensity were observed for the two geohelminths in this community. Prevalences and intensity had convex age profiles. Although repeated chemotherapeutic intervention reduced both prevalence and intensity levels, intensity was a more sensitive indicator than prevalence. The results indicate that age-targetting treatment at school children of 7-12 years of age would be an appropriate strategy for this community.
Soil-transmitted helminth (STH) infections of humans fall within the World Health Organization's (WHO) grouping termed the neglected tropical diseases (NTDs). It is estimated that they affect approximately 1.4 billion people worldwide. A significant proportion of these infections are in the population of Southeast Asia. This review analyses published data on STH prevalence and intensity in Southeast Asia over the time period of 1900 to the present to describe age related patterns in these epidemiological measures. This is with a focus on the four major parasite species affecting humans; namely Ascaris lumbricoides, Trichuris trichiura and the hookworms; Necator americanus and Ancylostoma duodenale. Data were also collected on the diagnostic methods used in the published surveys and how the studies were designed to facilitate comparative analyses of recorded patterns and changes therein over time. PubMed, Google Scholar, EMBASE, ISI Web of Science, Cochrane Database of Systematic Reviews and the Global Atlas of Helminth Infections search engines were used to identify studies on STH in Southeast Asia with the search based on the major key words, and variants on, "soil-transmitted helminth" "Ascaris" "Trichuris" "hookworm" and the country name. A total of 280 studies satisfied the inclusion criteria from 11 Southeast Asian countries; Brunei, Cambodia, Indonesia, Lao People's Democratic Republic (Lao PDR), Malaysia, Myanmar, Philippines, Singapore, Thailand, Timor-Leste and Vietnam. It was concluded that the epidemiological patterns of STH infection by age and species mix in Southeast Asia are similar to those reported in other parts of the world. In the published studies there were a large number of different diagnostic methods used with differing sensitivities and specificities, which makes comparison of the results both within and between countries difficult. There is a clear requirement to standardise the methods of both STH diagnosis in faecal material and how the intensity of infection is recorded and reported in future STH research and in monitoring and evaluation (M&E) of the impact of continuing and expanding mass drug administration (MDA) programmes.
Anthropometric and parasitological data from cross-sectional studies of two groups of primary school children (Group I of Indian origin, 325 boys and 259 girls, age = 7 years; Group II of Malay origin, 284 boys and 335 girls, age = 7-9 years) from two different ecological settings in Peninsular Malaysia were examined for epidemiological evidence of an association between hookworm infection and protein-energy malnutrition. In both ecological groups, significant weight, height and haemoglobin deficits were observed in children with hookworm infection after adjustment for covariables including Ascaris and Trichuris infection intensities and other child and family characteristics. The deficits were related to the intensity of infection based on egg counts. These findings suggest that hookworm may be an important determinant of chronic protein-energy malnutrition, as well as anaemia, in areas where diets are generally inadequate in protein, energy, and iron. Well-controlled intervention studies are needed to confirm these observations.
Albendazole, a benzimidazole derivative, was administered as a single dose of either 400 mg or 600 mg to two groups to ascertain the efficacy, tolerance and safety of the regimens. At a dose of 400 mg, a cure rate 35/36 (97%) against Ascaris was found. At 600 mg, the cure rate was 21/30 (70%), significantly lower than the 400 mg rate. Against Trichuris, albendazole at 400 mg had a cure rate of 21/48 (44%), at 600 mg there was a cure rate of 29/43 (67%). Mild side effects were noted in 7 individuals. Whether the moderate increase in efficacy against Trichuris and the loss of efficacy against Ascaris improves the cost:benefit ratio must be left to the prescriber of the drug.
A cross-sectional study was carried out in 2006 to determine the prevalence of Ascaris lumbricoides infection among Orang Asli (aborigines) children in Pos Lenjang, Pahang. A total of 71 faecal samples were collected from the children (40 girls and 31 boys) aged between 1-12 years. The samples were examined for the presence of the ova of A. lumbricoides using direct faecal smear and formalin-ether concentration techniques. 42.3%. The prevalence of A. lumbricoides infection was found to be slightly higher in males (45.2%) compared to females (40%) (p>0.05). The school-aged children showed higher prevalence of infection (48.6%) as compared to the preschool children (35.3%) (p