Reduced Efficacy of Anthelmintic Drugs


Approximately 1.5 billion people worldwide are affected by soil-transmitted helminth infections. Efficacy of current treatments is decreasing, as indicated in a systematic review and network meta-analysis by the Swiss Tropical and Public Health Institute, published in the British Medical Journal (BMJ). New drugs are therefore urgently needed to effectively fight parasitic worms.

Currently four main drugs are used to treat soil-transmitted helminthiasis: albendazole, mebendazole, levamisole and pyrantel pamoate. Over one billion tablets of albendazole or mebendazole are distributed every year in the frame of preventive chemotherapy programs. A systematic review and meta-analysis now indicates decreasing efficacy of these two drugs over the past two decades.

In addition, while mebendazole has low efficacy against hookworm, the efficacy of both is insufficient in treating Trichuris trichiura infections. "These results indicate the pressing need to develop new anthelminthic drugs," says Jennifer Keiser, Head of Helminth Drug Development at the Swiss Tropical and Public Health Institute (Swiss TPH). "As efficacy is decreasing over time, we must act now."

The study for the first time used a network meta-analysis approach to evaluate the efficacy of recommended drugs treating soil-transmitted helminth infections, thereby not only providing updated estimates on cure rates but also summary estimates of the egg reduction rates, a key indicator for anthelmintic drug efficacy. The meta-analysis by Swiss TPH was published on 25 September in the peer-reviewed journal BMJ.

About soil-transmitted helminth infections

Approximately 1.5 billion people are infected with at least one of the three types of soil-transmitted helminths: Ascaris lumbricoides, hookworm and T. trichiura. They are caused by parasitic worms which are transmitted by eggs present in human feces, which contaminate the soil in areas where sanitation is poor. Infected children are physically, nutritionally and cognitively impaired. Parasitic worm infections are a major public health concern among the poor and most vulnerable populations in Asia, Sub-Sahara Africa and the Americas.

Leading institution in helminth drug development

Swiss TPH is one of the leading institutions worldwide in discovering novel treatments and conducting clinical trials in the area of parasitic worms. On 7 and 8 December 2017, Swiss TPH hosts an international symposium on the topic of "Helminth Infection - From Transmission to Control" in Basel, Switzerland.