Schistosomiasis Control and Transmission in Uganda

Group photo of the members of the Lamberton Lab in Uganda

Neglected tropical diseases affect over 1.4 billion people and cause a greater disease burden than HIV/AIDS. Despite extensive mass drug administration (MDA), schistosomiasis remains a major public health issue, with a socio-economic impact second only to malaria amongst parasites. Those treated during MDA campaigns are rapidly re-infected, yet the critical pathways for this reinfection are not yet known and potential resistance to the drugs used to treat infection poses a real threat to this method of parasite control.

The Schisto-PERSIST project, led by Dr Poppy Lamberton, is evaluating novel strategies and new technologies to monitor the impact of MDA programmes, to identify threats to MDA effectiveness, and enhance control of schistosomiasis in sub-Saharan Africa.

Specifically this research is addressing five questions in the Mayuge district in Uganda:

1. What is the best way to monitor schistosome infections and drug efficacy?

2. Has drug resistance been selected for?

3. What is the potential for drug resistance to spread?

4. What other factors drive transmission?

5. What other factors affect parasite clearance?

The team is deploying innovative interdisciplinary methods including state-of-the-art DNA-chip diagnostics, novel application of genetic analysis to differentiate surviving worms from juveniles, use of drug screening technology to measure in vitro drug susceptibility, providing quantifiable in vitro phenotype without using mammals, combination of molecular techniques with mathematical models to elucidate the potential spread of phenotypes and an interdisciplinary approach deducing host effects in non-clearers.

These methods and technologies have not previously been used to assess MDA effectiveness for helminth infections. This research is enabling a comparative assessment of how transmission is affected by untreated adults and pre-school children, individuals with heavy infections, coinfections, and drug coverage. This will help identify optimal strategies to reduce transmission hotspots.

First published: 21 January 2021