A community study on the age and sex related prevalence, intensity infection and frequency distribution of Ascaris, Trichuris and hookworm was carried out in 205 Orang Asli (Aborigines) children (95 boys, 110 girls) aged 1-13 years. The overall prevalence of Ascaris, Trichuris and hookworm was 62.9%, 91.7% and 28.8%, respectively. Almost two-thirds of the children were infected with moderate and severe intensity infection of Trichuris, 46.3% had moderate to severe intensity infection of Ascaris. However only 1.5% had moderate intensity of hookworm infection. The prevalence and mean intensity infection (measured by eggs per g) of Ascaris was age-dependent; lower in age group 1-4 years reached peak and stable at age group 5 years and above. The prevalence of Trichuris was high in all age groups and it fluctuated with age; the mean intensity of infection of Trichuris (measured by eggs per g) was age-dependent. Hookworm infection also rose with age and reached peak at 5-6 years, following that the prevalence declined. The frequency distributions of Ascaris, and hookworm were overdispersed. A strong positive correlation (p < 0.001) were observed between Ascaris and Trichuris and between hookworm and Trichuris. A positive correlation (p < 0.01) were also observed between Ascaris and hookworm.
To access the effectiveness of the treatment of soil-transmitted helminthiasis (STH) on the growth of primary school children, 353 children were block stratified to receive either mebendazole plus pyrantel oxantel pamoate every three months or a placebo. The children were followed for two years with 89% completing the trial. Follow-up stools indicated that the treatment was efficacious for ascariasis and trichuriasis. There was virtually no hookworm infection. The children were malnourished as measured by the number below -2 SD of height and weight standards. There was no difference in height or weight between the treatment and control groups by sex initially or at the end of two years of follow-up. The treatment of Ascaris and Trichuris had no effect on growth parameters. The effect of STH on growth may be mediated through hookworm infections.
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.
A survey of workers and families resident in an oil palm estate in Malaysia revealed high incidence of parasitic infections. The commonest parasites are T. trichiura (56%), A. lumbricoides (52%), hookworm (28%), Entamoeba coli (11.3%) and Giardia lamblia (11.3%). Mixed infections by two or more parasites was seen in 46% of the subjects. Anaemia was present in 70% of children with hookworm infection. Eosinophilia was observed in 69% of subjects. One each of Hymenolepis nana and Hymenolepis diminuta infection was detected. This is the first report of Hymenolepis diminuta infection in man in Malaysia.
Faecal samples from patients admitted to the District Hospital in Balik, Pulau, Penang revealed high infection rates for Ascaris lumbricoides, Trichuris trichiura and hookworms. The prevalence rates were Trichuris trichiura 51.7%, Ascaris lumbricoides 31.9% and hookworm 37.2%. The overall highest infection is among the Malays (79%), the least being among the Chinese (61.1%). The prevalence of Ascaris lumbricoides was highest in the 11-20 age group. The prevalence of Trichura was highest in the 51-60 age group, Ascaris and Trichuris infections is higher among the males but hookworm infection is higher among the females. 72.6% of the patients were infected with at least one type of helminth and 32.9% of the patients were infected with at least 2 types of helminths.
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.
Intestinal permeability of 246 early primary schoolchildren at 2 schools (106 of whom were infected with intestinal helminths) was assessed by using the lactulose/mannitol differential absorption test. The ratio of the urinary recoveries of lactulose and mannitol was determined after oral administration of a standard solution of the 2 sugars. Assessment of intestinal permeability was repeated on 100 infected children after treatment and on a cohort of 68 uninfected children. Infected and uninfected groups were compared with respect to baseline lactulose/mannitol ratio (L/M1) and change in lactulose/mannitol ratio between assessments (delta L/M). The correlations between baseline intensity of infection and L/M1, and between fall in intensity and delta L/M, were evaluated. Based on a crude index of socioeconomic status, each child was assigned to one of 3 socioeconomic groups; all but 3 children belonged to either groups 2 or 3. Trichuris trichiura and Ascaris lumbricoides were the 2 predominant infections; the hookworm infection rate was relatively low. The results suggested that helminthiasis exerted only a marginal effect on intestinal permeability, the impact of which in children from lower socioeconomic backgrounds was negligible in comparison with the cumulative effects of other factors.
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.
Stool examination of 249 early primary schoolchildren at 2 schools in north-eastern peninsular Malaysia revealed that 73 were infected with Ascaris lumbricoides, 103 with Trichuris trichiura, and 18 with hookworms. Infected children were treated with a single dose of 400 mg of albendazole. The school attendance records during a 60 d period before treatment and 2 consecutive 60 d periods after treatment were examined. The absenteeism rate did not improve more among infected children after treatment than it did among the uninfected control children. The correlation between worm intensity and the number of lost school-days was poor. There was no evidence that intestinal helminthiasis caused school absenteeism among this group of children.
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.
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.
This study was conducted to determine the prevalence of intestinal parasites among children and adult Orang Aslis (Aborigines) from different locations in Perak. Faecal samples were collected and analyzed using the direct smear and formal ether sedimentation technique. Some of the faecal samples were stained using the Modified Acid fast stain for Cryptosporidium. Nail clippings of the respondents and the soil around their habitat were also analyzed. Of the 77 stool samples examined, 39 (50.6%) were positive for at least one intestinal parasite. The most common parasite detected was Trichuris trichiura (39.0%) followed by Ascaris lumbricoides (26.9%), Entamoeba coli (5.2%), Giardia lamblia (5.2%), Blastocystis hominis (3.9%), hookworm (3.9%), Entamoeba histolytica (1.3%), Iodamoeba butschlii (1.3%) and Cryptosporidium sp. (1.3%) respectively. Some respondents had single parasites (24.7%), some with two parasites (18.2%). Some with three parasites (6.5%) and one had four parasites species (1.3%). The parasites were slightly more common in females (54.7%) than males ((41.7%). The parasites were more common in the 13-20 year age group (90.9%) followed by 1-12 years (69.6%), 21-40 year age group (34.8%) and least in the 41-60 year age group (27.8%). Nail examinations of the respondents did not show any evidence of parasites. One had a mite, three had pollen grains and one had yeast cells isolated from the finger nails. Soil samples taken around their houses showed only one sample with a nematode ova and one with oocyst which was of a non human origin.