Discussion
helminth infections, helminths
HAND INFECTION, HELMINTH INFECTIONS
Preventive chemotherapy has been a cornerstone strategy in the fight against soil-transmitted helminth infections since the early 1990s. Nevertheless, soil-transmitted helminths remain a major public health problem, partly due to the absence of efficacious, broad-spectrum single-dose treatment options suitable for mass drug administration programmes. Moxidectin is readily available because of repurposing and is one of the few alternatives to albendazole and mebendazole and the combination of ivermectin and albendazole, which are widely used.In this study, we found that moxidectin and albendazole was inferior to ivermectin and albendazole in adolescents infected with T trichiura on Pemba Island, Tanzania. This finding is surprising given our previous results, which showed high efficacy of moxidectin. In more detail, in this study the cure rate of 34·3% for moxidectin and albendazole was considerably lower than those described in two other studies.Further studies in other settings might reveal useful insights as The cure rate of 26·3% for albendazole was substantially higher in a previous trial conducted on Pemba Island by Hürlimann and colleagues,We had hypothesised that the longer half-life of moxidectin and albendazole compared with ivermectin and albendazole might result in extended effects and hence included a longer efficacy assessment scheme (ie, follow-up at 14–21 days, 5–6 weeks, and 3 months after treatment). No benefit of moxidectin and albendazole compared with ivermectin and albendazole was observed at the timepoints of 5–6 weeks and 3 months after treatment. A potential beneficial effect of the longer half-life of moxidectin was not great enough to outweigh the superiority of ivermectin and albendazole. However, if moxidectin and albendazole were to be applied once or twice a year, as is the case for most mass drug administration schemes against soil-transmitted helminths, the longer half-life of moxidectin might result in a cumulative benefit over time.This study had some limitations. First, a double-blind study design is favourable to the open-label approach. The reason we did not attempt double-blinding was because of the large number of groups with a highly variable number and shape of tablets in each treatment group. Therefore, we deemed it unethical to expose participants to many various placebos. Furthermore, the laboratory technicians assessing egg counts were fully masked to treatment allocation, which allows for unbiased results. Second, we only included participants aged 12 years or older since moxidectin is currently approved only for this age group, which is a notable limitation of the drug as previous studies have found a high prevalence and infection intensities in children younger than 12 years.In conclusion, this study showed inferiority of moxidectin and albendazole over ivermectin and albendazole against 