Triple Combinations Against Hookworm Infections in Lao

Overview

More than one billion people are infected with soil-transmitted helminths (STH, A. lumbricoides, hookworm or Trichuris trichiura). Preventive chemotherapy - i.e. annual or biannual treatment of at-risk populations with albendazole or mebendazole is the current strategy against STH. However, the efficacy of both drugs is only moderate against hookworm and low against T. trichiura. For increasing the efficacy and to avoid drug resistance, new drugs or the combination of different drugs is the way forward. In this randomised controlled trial, we assess the efficacy (based on cure rates) of different drug combinations in school-aged children in Lao. 420 hookworm positive children will be treated: 140 with albendazole-oxantel pamoate, 140 with albendazole-pyrantel pamoate-oxantel pamoate treatment arms, 70 with pyrantel pamoate-oxantel pamoate and 70 with mebendazole-pyrantel pamoate-oxantel pamoate. Two stool samples will be collected at baseline and follow-up (14-21 days after treatment) and analysed with Kato-Katz.

More than one billion people are infected with A. lumbricoides, hookworm or Trichuris trichiura, the so-called soil-transmitted helminths (STH). Preventive chemotherapy - i.e. annual or biannual treatment of at-risk populations, is the current strategy against STH advocated by the World Health Organization. However, the currently used drugs albendazole and mebendazole have only moderate efficacy against hookworm and low against T. trichiura. The main challenge is their temporal decrease in efficacy, which might be associated with drug resistance, as it was shown in veterinary medicine. For increasing the efficacy and to avoid drug resistance, new drugs or the combination of different drugs is the way forward. The primary objective of this study is to assess the efficacy (based on cure rates \[CR\]) of the three combinations, i.e. albendazole-oxantel pamoate, pyrantel pamoate-oxantel pamoate and albendazole-pyrantel pamoate-oxantel pamoate in school-aged children infected with hookworms in Laos. Secondary objectives include; i) a proof of concept, investigating the difference between the two triple combinations albendazole-pyrantel pamoate-oxantel pamoate versus mebendazole-pyrantel pamoate-oxantel pamoate (based on CRs), ii) egg reduction rates (ERR) against hookworm and ERRs/CRs against A. lumbricoides and T. trichiura and iii) tolerability of the 4 combinations. Two stool samples will be collected from school-aged children (age 6-15) at baseline. 420 hookworm positive children will be treated: 140 with albendazole-oxantel pamoate, 140 with albendazole-pyrantel pamoate-oxantel pamoate, 70 with pyrantel pamoate-oxantel pamoate and 70 with mebendazole-pyrantel pamoate-oxantel pamoate treatment arms The medical history of the participating children will be assessed with a standardized questionnaire, in addition to a clinical examination carried out by the study physician on the treatment day. Children will be interviewed before treatment for clinical symptoms and 3 and 24 hours after treatment about the occurrence of adverse events. The efficacy of the treatment will be determined 14-21 days post-treatment by collecting another two stool samples. All stool samples will be examined with duplicated Kato-Katz thick smears.