Trials using albendazole and mebendazole, as single 400 mg dose treatments, against soil-transmitted helminths, were carried out in 7-9 and 10-12 years-old schoolchildren living in urban and rural environments in Penang, Malaysia. Both drugs were equally effective in treating trichuriasis and ascariasis in both age groups and environments. However, mebendazole is not so effective in the treatment for hookworms when compared to albendazole. It is suggested that albendazole should be considered the drug of choice for mass chemotherapy for Penang.
A cohort of one hundred 8-9 year old school children in Northeastern Peninsular Malaysia underwent stool examination, weight and height measurements. Seventy-three children were infected with Ascaris lumbricoides and/or Trichuris trichiura. All infected children were treated with albendazole at baseline, 6 months and 9 months. Measurements were repeated on all but 2 children at 1 year. Repeat stool examination (n = 94) at 1 year revealed a marked reduction in the level of Ascaris infection and a modest reduction in Trichuris infection. There was no difference in net growth between treated children and uninfected controls. Post-hoc analysis by gender however revealed that infected girls (n = 33) experienced significantly higher increments in weight, height and weight for age. Furthermore, children found to be infected at baseline level but worm free at follow-up, were observed to have experienced greater increments in height and height for age. The evidence suggests that periodic antihelminthic treatment may have a positive effect on the growth of subsets of pre-adolescent children but it is emphasised that further work is required to validate these findings.
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.
Albendazole, a new anthelmintic drug was evaluated in Malaysia in 91 patients, with single or mixed infections of Ascaris, Trichuris, and hookworm. Albendazole was administered as a single dose of 400 mg, 600 mg, or 800 mg. The cure rate for Ascaris at all three doses was 100% at days 14 and 21 post-treatment; for hookworm it was 98.8%, 100% and 98%, respectively, at day 14 and 68.8%, 100% and 84%, respectively, at day 21; for Trichuris it was 31.2%, 57.1% and 42.3%, respectively, at day 14 and 27.3%, 60.9% and 48.0%, respectively, at day 21. The egg reduction rate at day 21 was 100% at all three doses for Ascaris, 94.5%, 100% and 96.1%, respectively, for hookworm; and 39.2%, 85.1% and 72.8%, respectively, for Trichuris. There were no side effects, and biochemical examination of blood and urine did not indicate any unfavourable changes. Based on this trial, the recommended dosage for Ascaris and hookworm is a 400 mg single dose, and for Trichuris is a 600 mg single dose. Albendazole appears to be more effective than other available anthelmintic drugs.
Children with severe Trichuris trichiura infection pose significant social, clinical, and therapeutic problems in Malaysia. Thirty such children were investigated, and mebendazole was found to be safe and effective in the treatment of severe trichuriasis but it had to be given for a longer period than currently recommended. A poor correlation was found between egg load and worm burden in these children. Direct visualization of the rectal and colonic mucosa was the most reliable method of assessing severity in untreated cases, and response to treatment. The eggs of Trichuris that had been exposed to mebendazole were morphologically altered and not viable when incubated. This may be of considerable epidemiological importance.
A study to determine the effect of antihelminthic treatment on growth and nutritional status was undertaken on 103 children in the second grade of primary school, 71 of whom were found to be infected with Ascaris lumbricoides or Trichuris trichiura. The median Ascaris and Trichuris intensities in the infected group were 19,600 (range; 0-488,000) and 2,800 (range; 0-84,600) eggs per gram of feces respectively. Forty-three children harbored both types of worm. Fourteen weeks after two 400 mg doses of albendazole were administered to infected children, the increases in weight, height, weight for age, height for age and weight for height were significantly higher among infected children than controls who were uninfected at baseline. The observed gains were independent of sex and socioeconomic status. Decrease in log transformed Trichuris intensity correlated with increases in weight (r=0.24; p=0.02) and weight for age (r=0.20; p=0.06) but decrease in Ascaris intensity did not correlate with increases in any of the anthropometric parameters. The results suggest that antihelminthic treatment has beneficial short-term effects on growth and nutritional status of a modest magnitude among early primary schoolchildren in the area.
The efficacy of a single-dose 400 mg albendazole to treat Ascaris, Trichuris and hookworm infection was studied in Orang Asli community. Kato-Katz examination was performed on fecal samples which were collected before treatment, 1 and 4 months after treatment. A total of 123 children were involved in all three surveys. The cure rate of Ascaris infection was 97.4% and the egg reduction after treatment was 99.9%. The cure rate for hookworm infection was 93.1% with 96.6% egg reduction. Although the cure rate was low in Trichuris infection (5.5%), egg reduction was more evident (49.1%). The reinfection rate at 4 months after treatment was 54.5%, 3.6% and 10.3% for Ascaris, Trichuris and hookworm infection, respectively. Within 4 months after treatment almost one-fifth children with Ascaris and hookworm infection reached pre-treatment intensity infection. In Trichuris infection, however more than half of the children reached their pre-treatment intensity infection at 4 months after treatment. Findings suggest that 4-monthly targeted periodic treatment with 400 mg single-dose albendazole in highly endemic areas can have a significant impact on intensity infection of Ascaris and hookworm, but not on Trichuris infection.
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.
Fecal specimens collected from 456 school children in Gombak, Malaysia, revealed an overall prevalence rate of 62.9%. The most common parasite found was Trichuris trichiura (47.1%) followed by Giardia intestinalis (14.7%), Entamoeba coli (11.4%), Entamoeba histolytica (9.9%) and Ascaris lumbricoides (7.9%). Infection rates were high among the Indonesian immigrant workers' children (90%) followed by the Orang Asli (79.5%), Malay (59.4%) and Indians (36.4%). Females (66.3%) had a higher prevalence rate than the males (58.5%). The prevalence of infection was found to be associated with the socio-economic status, water supply, sanitary disposal of feces and family size. Albendazole administered as a single dose (400 mg) was found to be effective against Ascaris (100%) and hookworm (92.3%) but was not effective against Trichuris (39.2%).
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.
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.
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.
We studied asymptomatic primary schoolchildren in northeastern Malaysia with light to moderate trichuriasis to determine the effect of albendazole treatment on growth rates and TNF-alpha levels. Thirty-seven schoolchildren aged 6-7 years with stool samples positive for Trichuris trichiura and negative for other geohelminths and protozoa were randomized to receive albendazole 400 mg or a placebo daily for 2 days. Anthropometric parameters at baseline, 3, 6 and 12 months were compared between the 2 groups. The placebo group had a significantly greater increase in height (p = 0.04) than the albendazole treatment group. There were no significant differences in urinary TNF-alpha levels (p = 0.8) between the 2 groups and no significant changes between baseline and 1 month post-treatment levels. Further studies are needed to determine the etiology of this apparent association between the albendazole treatment group and the delay in growth rate at 6 months post-treatment.
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.