Soil-transmitted helminthiasis: the efficacy of recommended drugs, new drugs and combinations

Soil-transmitted helminthiasis is caused by an infection with Ascaris lumbricoides, the hookworms Ancylostoma duodenale and Necator americanus, and Trichuris trichiura. Around the world an estimated 1.5 billion people are infected with at least one of these species. While A. lumbricoides and T. trichiura are more prevalent in school-aged children, hookworm infections are common in adults. Infected people live predominantly under poor conditions in the least developed settings. Chronic infections with soil-transmitted helminths could lead to growth stunting, intellectual impairment, cognitive and educational deficits, malnutrition, and iron deficiency anaemia. The global estimated burden of soil-transmitted helminth infections was estimated at 3.3 million disability adjusted life years in 2016.
The overall aim of the PhD thesis was to contribute to better treatment options for soil-transmitted helminthiasis. We first meta-analysed the efficacy of the currently available anthelminthic drugs (albendazole, mebendazole, levamisole and pyrantel pamoate). Since none of the existing drugs have a high efficacy against all three soil-transmitted helminths and the efficacy decreased over time, new drugs or drug co-administrations (with a different efficacy profile) were evaluated during this PhD thesis in three different randomized clinical trials. In the first, a weight-independent dose of oxantel pamoate against T. trichiura was investigated, in the second, the efficacy of tribendimidine was evaluated alone and in co-administration against hookworm and in the third, the improved efficacy of triple drug therapies over co-administrations was assessed. Moreover, the new remote location online diagnostic tool FECPAKG2 was compared to the current standard method Kato-Katz.