# Snail-Related Studies of Transmission & Control of Schistosomiasis in Kenya

> **NIH NIH R37** · UNIVERSITY OF NEW MEXICO · 2022 · $364,162

## Abstract

Sc histosomiasis is one of the world's most common neglected tropical diseases, currently infecting over 200
million people, with 90% of cases occurring in tropical Africa. The involvement of freshwater snails as vectors
imparts considerable stability to the schistosome life cycle because snails support the prolific production by
asexual reproduction of cercariae, the infective stage of the parasite for people. Efforts thus far to control
schistosomes in snails have had but limited success. Our work's overall goal is to identify innovative new ways to
interrupt the development and transmission of Schistosoma mansoni in its obligatory Biomphalaria snail hosts,
especially in the context of the Lake Victoria basin. Rather than to attempt to suppress large snail populations
across broad endemic areas, our approach is to find specific ways to target infected snails and the larval stages
of schistosomes living within them . Our field studies also constantly remind us of the impact a warming c limate
may have on vector snails and the schistosomes developing within them. Building on both lab- and field-based
discoveries made in our ongoing funding period, we propose the following new aims: Aim 1. We seek to learn if
immune responses we have shown to be relevant to resistance in a lab model, the Neotropical snail B. glabrata
and S. mansoni, are also at play in African Biomphalaria taxa in western Kenya. The transcriptomics and other
studies we propose will identify novel characteristics of the responses of African snails to schistosome infection
and how snail responses to S. mansoni might be affected by warming c limates. Aim 2. We aim to characterize the
means whereby larval trematodes, especially ubiquitously common cattle-transmitted amphistomes, suppress and
supplant the development of S. mansoni sporocysts in African Biomphalaria taxa . We will use a combination of in
vivo and in vitro approaches coupled with transcriptomics, proteomics and metabolomics techniques to address
this issue. Aim 3. We hypothesize that shore-dwelling B. sudanica suffers constant exposure to many different
trematode species, including S. mansoni, and have developed a generalist immune strategy featuring tolerance
to minimize trematode impact. In contrast, a close relative, B. choanomphala, lives in a deepwater refugium from
infection, and we predict will show diminished immune responsiveness and lack of tolerance responses upon
challenge with trematodes. Our aims all seek to characterize novel ways to interfere with the development of
schistosome larval development in snai ls, build a two-way bridge between lab and field studies and will enable us
to continue a 30+ year collaboration between biologists at UNM and the Kenya Medical Research Institute,
emphasizing training of young scientists in medical malacology.
RELEVANCE (See instructions):
Schistosomiasis is one of the world's most common neglected tropical diseases. Its resilience is partly due to the
reliance of schist...

## Key facts

- **NIH application ID:** 10295200
- **Project number:** 4R37AI101438-11
- **Recipient organization:** UNIVERSITY OF NEW MEXICO
- **Principal Investigator:** ERIC SAMUEL LOKER
- **Activity code:** R37 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $364,162
- **Award type:** 4C
- **Project period:** 2012-05-15 → 2027-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10295200

## Citation

> US National Institutes of Health, RePORTER application 10295200, Snail-Related Studies of Transmission & Control of Schistosomiasis in Kenya (4R37AI101438-11). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10295200. Licensed CC0.

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