Efficacy of triple dose albendazole treatment for soil-transmitted helminth infections

Abstract

In Malaysia, soil-transmitted helminth (STH) infections still persist among indigenous communities. In the past, local studies have focused mostly on epidemiologic aspects of STH infections with a scarcity of information on the efficacy of deworming treatment. The present study consisted of 2 phases: a cross-sectional phase on current epidemiological status and risk factors of STH infections and a longitudinal study over 6 weeks on triple dose albendazole efficacy against STH infections. A total of 253 participants were recruited at baseline and a pre-tested questionnaire was administered to obtain information on socio-demographics, environmental and behavioural risk factors. Stool samples were evaluated using a modified Kato-Katz technique. Cure rate (CR) and egg reduction rate (ERR) were assessed at 3 weeks following a 3-day course of 400mg albendazole treatment and infection status were observed again at 6 weeks. Baseline positivity of trichuriasis, ascariasis and hookworm infections were 56.1%, 11.9% and 20.2%, respectively. Multivariate analysis showed age below 18 years old (P = 0.004), without latrine in house (P = 0.042) and indiscriminate defecation (P = 0.032) were associated with STH infections. In the longitudinal study (N = 89), CR for trichuriasis was 64.6%, while CR of 100% was observed for both ascariasis and hookworm. ERR was above 90% for all three STH species. A rapid increased of Trichuris trichiura egg output was observed at 6 weeks. In conclusion, STH infections are highly prevalent among indigenous communities. Children and teenagers, poor sanitation and hygiene behaviour were determinants for STH infections. Triple dose albendazole is found to be efficacious against Ascaris lumbricoides and hookworm infections but has moderate curative effect with high ERR against T. trichiura. Although triple dose albendazole regimen has logistic challenges and may not be a routine option, consideration of this treatment regime may still be necessary in selective communities to reduce high intensity of T. trichiura infection.

Fig 1. Forest plot of univariate analysis of potential risk factors associated with STH infections among the study population.

CI = Confidence interval; * = Significant risk factors (P<0.05).

Fig 2. Forest plot of multivariate analysis of potential risk factor associated with STH infections among the study population.

Adjusted OR = Adjusted Odds ratio; CI = Confidence interval; * = Significant risk factors (P<0.05).

Fig 3. T. trichiura infection patterns over the three time points among T. trichiura positive participants at baseline (N = 48).

Different patterns of T. trichiura infection were observed among 48 infected participants following 3 doses of albendazole treatment: (A) Overall T. trichiura infection patterns over 3 time points (n = 48). (B) cured from infections at 3 weeks and remain negative at 6 weeks (n = 24), (C) cured from infections at 3 weeks post-treatment but increased of egg output at 6 weeks post-treatment (n = 7), (D) egg output was reduced at 3 weeks post-treatment and become negative at 6 weeks post-treatment (n = 3), (E) showed reduction of egg output following treatment (n = 5), (F) showed reduction of egg output at 3 weeks post-treatment and remain unchanged at 6 weeks post-treatment (n = 3), (G) showed increment of egg output at 6 weeks post-treatment after a reduction at 3 weeks post-treatment (n = 6).