Soil-Transmitted Helminthiasis

The goal of this Phase III clinical trial is to evaluate the efficacy, safety, and acceptability of different treatment regimens for Trichuris trichiura infection in schoolchildren aged 6 to 15 years living in La Moskitia, Honduras, an area with a high burden of soil-transmitted helminth infections. The main questions it aims to answer are: * Are combination treatments of albendazole and ivermectin more effective than albendazole alone for treating Trichuris trichiura infection? * Does a fixed-dose combination (FDC) of albendazole and ivermectin achieve cure rates comparable to co-administration of the two drugs? * How effective are the different treatment regimens against other soil-transmitted helminths, including Strongyloides stercoralis? * What adverse events occur following treatment with the different regimens? * How acceptable are the different treatment regimens to children and their caregivers? Researchers will compare four treatment groups: placebo, albendazole alone, albendazole plus ivermectin, and a fixed-dose combination of albendazole plus ivermectin. Participants will: * Be randomly assigned to one of the four treatment groups. * Receive a single dose of the assigned treatment. * Provide stool samples before treatment and approximately 21 days after treatment. * Undergo laboratory testing using quantitative real-time PCR (qPCR) to detect and quantify helminth infections. * Be monitored for adverse events after treatment. * Complete acceptability assessments together with their caregivers. The study will provide evidence on the efficacy, safety, and acceptability of a fixed-dose combination of albendazole and ivermectin and its potential use as a simplified treatment strategy for the control of soil-transmitted helminth infections in endemic settings.