# Molecular Determinants and Behavioral Fingerprints of Schistosome Miracidia Host-Seeking

> **NIH NIH R15** · UNIVERSITY OF WISCONSIN EAU CLAIRE · 2024 · $369,431

## Abstract

Schistosomiasis is a disease caused by chronic infections of human schistosomes, parasitic ﬂatworms
that are transmitted by aquatic snails. Schistosomes cause disease in over 250 million people but has
been designated as a Neglected Tropical Disease because of the outsized disease burden in
comparison to the investment given to it by the global health community. Schistosomiasis is controlled
primarily by mass drug administration (MDA) to people living in endemic areas. Though MDA has had
incredible success in reducing the burden of disease, many locations exist where schistosome
prevalence remains high despite repeated MDA with high coverage. In these cases, the stakeholders
are encouraged to implement snail control through chemical molluscicide treatment of local waters.
Chemical molluscicides are effective but can have harmful ecological consequences by eliminating
target snails and, at times, off-target invertebrates and plants. New strategies could be developed that
reduce the density of infected snails without reducing populations of snails themselves. Miracidia, the
aquatic snail-infective stage of schistosomes, utilize a variety of sensory modalities during host-seeking
(i.e., geosensation, photosensation, and chemosensation), resulting in accumulation near potential
snail hosts. Once a miracidium enters the active space of a snail – the area in which it can sense snail
chemical cues – it undergoes a distinct behavioral transition that results in contact with the snail. The
host-seeking and penetration behaviors have been qualitatively described by careful observation, but
quantitative models of these behaviors have yet to be generated, making them difﬁcult to
experimentally interrogate. Further, though a variety of circumstantial evidence exists that supports a
secreted glycosylated peptide as the primary snail cue sensed by miracidia, this has not been
conﬁrmed in vivo. This project will seek to quantitatively describe miracidia behaviors in the presence
and absence of snails and extract behavioral ﬁngerprints from high-resolution tracking data generated
from a unique, bespoke recording device with a large ﬁeld of view. Behavioral ﬁngerprints and an
optimized high-throughput experimental approach will set a foundation for screening of environmental
stimuli and small molecules for inhibitory effects on miracidia sensation of snail cues. In parallel, the
snail secreted peptide that is hypothesized to stimulate miracidia accumulation will be validated in vivo,
and a comparative approach using new genomic reference data from several schistosome snail hosts
will explore this critical host-parasite interaction among three 4 snail species and 2 schistosome
species. These comparisons will allow for the generation of a consensus sequence for the stimulatory
peptide, which could act as a scaffold for future optimization for activity on miracidia.

## Key facts

- **NIH application ID:** 10875010
- **Project number:** 1R15AI183095-01
- **Recipient organization:** UNIVERSITY OF WISCONSIN EAU CLAIRE
- **Principal Investigator:** Nicolas J Wheeler
- **Activity code:** R15 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $369,431
- **Award type:** 1
- **Project period:** 2024-08-21 → 2027-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10875010

## Citation

> US National Institutes of Health, RePORTER application 10875010, Molecular Determinants and Behavioral Fingerprints of Schistosome Miracidia Host-Seeking (1R15AI183095-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10875010. Licensed CC0.

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