Parasitic Worm Infections - Helminthiases

Parasitic worm infections are a major public health issue in many tropical and subtropical low-income communities. In the case of soil-transmitted helminthiases, schistosomiases and foodborne trematodiases, infections are transmitted by eggs released in feces or urine which contaminate soil and water bodies. A lack of access to improved sanitation and safe water increases the risk of transmission as do unsafe nutrition practices. Different helminth infections can compromise the nutritional status of infected people and animals and affect cognitive processes or induce tissue damage resulting in blindness, lymphedema and other symptoms. Certain helminths are also classified as carcinogenic agents. The morbidity and mortality caused by helminth infections can debilitate whole communities and contribute to poverty in endemic areas.

The Commitment of Swiss TPH

Swiss TPH is active in a broad range of activities related to research and control of parasitic worm infections. The work comprises basic research, drug discovery and clinical trials, evaluation and development of new diagnostic tools, modelling and mapping of risk areas and burden of disease, support of countries in building their control and elimination programmes as well as teaching and training both in Switzerland and in endemic areas.

Behavior change interventions

Zanzibar Elimination of Schistosomiasis Transmission

Urogenital schistosomiasis used to be a major public health problem in Zanzibar, Tanzania. In the past century, the prevalence has been reduced significantly and the elimination of disease and interruption of transmission is now in reach. In 90 schools and communities on Unguja and Pemba island, Swiss TPH assessed if snail control or behaviour change interventions have added benefits to bi-annual mass treatment of the population with praziquantel.

Link to Project

Evaluation of drug candidate combinations

Combination Chemotherapy for Soil-Transmitted Helminthiasis

Drug combinations for the treatment of soil-transmitted helminthiasis are receiving increasing attention. Swiss TPH has conducted a series of pivotal trials over the past years, for example evaluating the efficacy and safety of oxantel pamoate-albendazole. Swiss TPH also aims to conduct preliminary studies on the efficacy of albendazole and ivermectin in dose-response relationship studies in different population subgroups and study pharmacokinetic properties of ivermectin. In addition, studies have been launched to investigate the safety and efficacy of combinations including tribendimidine and moxidectin.

Poor sanitary facilities increase the risk for infections

Tuberculosis and Helminth Co-Infection in preschool-aged Children

Despite the high prevalence of helminth infections among preschool-aged children, control programmes in sub-Saharan African countries primarily focus on school-aged populations. Swiss TPH assesses the prevalence of helminth infections and determines risk factors for infection among preschool-aged children in Dar es Salaam, Tanzania. The study also evaluates the association of helminth infection and TB in children under five, as helminth infections may impair the immune response against other infectious diseases.

More about TB

Schistosoma-infested lake in Southern Côte d'Ivoire

Transmission Dynamics and Hybridization of Human and Animal Trematodes

The project investigates the population structure and transmission of Schistosoma and Fasciola species and their hybrids in Côte d'Ivoire using genetic methods (ddRAD sequencing, SNP analysis). The aim is to determine the exact species present, their relative frequencies, and the transmission networks between the various human and animal hosts. 

Raw fish plays a role in O. viverrini infections

Modelling Transmission Dynamics of Opisthorchis viverrini

O. viverrini, a liver fluke, is common in South-East Asia. Swiss TPH works on deterministic population-based and stochastic individual-based models of O. viverrini transmission. This creates a basis for comparing likely effects of different control strategies in reducing parasite transmission and burden, assessing the relative contribution of reservoir hosts, and the impacts of varying fishing practices. The project will provide a basis for rational planning of control, especially in the context of a new control programme in Lao PDR.