Risk assessment for the implementation of controlled human Schistosoma mansoni infection trials in Uganda

Jan Pieter Koopman,Maria Yazdanbakhsh,Jacent Nassuuna,Alison M Elliott,Emmanuella Driciru,Pontiano Kaleebu,Moses Egesa,Gijsbert Van Willigen,Moses Adriko,Gyaviira Nkurunungi,Narcis Kabatereine,Edridah Tukahebwa,Stephen Cose,Meta Roestenberg,Anne Wajja

doi:10.12688/aasopenres.12972.1

Abstract

Schistosomiasis is a parasitic infection highly prevalent in sub-Saharan Africa, and a significant cause of morbidity; it is a priority for vaccine development. A controlled human infection model for Schistosoma mansoni (CHI-S) with potential to accelerate vaccine development has been developed among naïve volunteers in the Netherlands. Because responses both to infections and candidate vaccines are likely to differ between endemic and non-endemic settings, we propose to establish a CHI-S in Uganda where Schistosoma mansoni is endemic. As part of a “road-map” to this goal, we have undertaken a risk assessment. We identified risks related to importing of laboratory vector snails and schistosome strains from the Netherlands to Uganda; exposure to natural infection in endemic settings concurrently with CHI-S studies, and unfamiliarity of the community with the nature, risks and rationale for CHI. Mitigating strategies are proposed. With careful implementation of the latter, we believe that CHI-S can be implemented safely in Uganda. Our reflections are presented here to promote feedback and discussion.

Highlights

Schistosomiasis is a parasitic infection affecting approximately 230 million people worldwide[1]
The issue of variable Schistosoma mansoni infection susceptibility in Ugandan snails is mentioned in both option 2 and 3
Under option 3: a paragraph was added on procedures for cloning a Ugandan strain for controlled human infection model for Schistosoma mansoni (CHI-S)

Summary

Information on the scoring of risks was attached to each table

3. The issue of variable Schistosoma mansoni infection susceptibility in Ugandan snails is mentioned in both option 2 and 3. 4. Under option 3: a paragraph was added on procedures for cloning a Ugandan strain for CHI-S. 5. Under option 3: the sentence on dose-finding was removed, because all three options would need dose-finding to balance tolerability and attack rate. 6. In ‘Natural infection during trial period’ we clarified the sentence on female single-sex models and on the risk of introducing a hybridised strain into the environment. 7. A paragraph was added on remuneration for participating in the trial and the risks associated ( added to Table 5)

Background

Discussion

Cohen J

Loewenberg S

Findings

Cose S