# Evaluating the possible transmission in California of food-borne zoonotic trematode parasites carried by the introduced snail Melanoides tuberculata

> **NIH NIH R03** · UNIVERSITY OF CALIFORNIA, SAN DIEGO · 2021 · $78,854

## Abstract

Summary
Food‐borne trematodiases are caused by trematode parasites and can involve pathologies ranging
from abdominal pain, chronic cough, hepatomegaly, bile duct cancer, or even brain hemorrhage.
Almost a billion people around the world are estimated to be at risk of infection. Despite their
global importance, food‐borne trematodiases are not typically considered to be a public health
issue in the United States. This lack of concern may have previously been justified: trematodes are
carried by first intermediate host snails, and the US historically lacked the snail species known to
carry injurious human‐infecting trematodes. However, one such host snail, Melanoides
tuberculata, has now been introduced and established in the United States. Three of its
human‐infecting trematodes have co‐established with the snail. Further, preliminary
sampling of southern Californian snails reveals that at least two of these human‐infecting
trematodes have been introduced to the western US. The introduction of this snail and some of
its parasites calls for an evaluation of the possible emergence of food‐borne zoonotic trematodiases
originating from the introduced snail in the United States.
The proposed research will involve a systematic survey throughout southern California to quantify
the presence of the intermediate host snail at 56 fishing localities, and the presence and abundance
of its trematode parasites. Further, at a subset of those localities, the investigation will confirm that
the trematode stages directly infectious to humans are, indeed, present in fishes that people catch
and eat.
Food‐borne trematodiases are not on the radar as a public health concern in the United States, but
this work may reveal that they should be. The proposed research will provide the first extensive
evaluation in the United States of a public health concern involving the possible emergence of food‐
borne trematodiases originating from trematodes carried by the introduced snail, M. tuberculata.
By delineating the extent of this potential public health problem in southern California, this
research will (1) provide a foundation for additional epidemiological research in southern
California and elsewhere in the nation, and (2) open the door for public and veterinary health
agencies to take preventative measures to reduce transmission and to inform clinicians of the
possible occurrence of previously unappreciated, and potentially undiagnosed, food‐borne zoonotic
trematodiases.

## Key facts

- **NIH application ID:** 10110457
- **Project number:** 1R03AI156569-01
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN DIEGO
- **Principal Investigator:** Ryan F Hechinger
- **Activity code:** R03 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $78,854
- **Award type:** 1
- **Project period:** 2020-12-01 → 2022-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10110457

## Citation

> US National Institutes of Health, RePORTER application 10110457, Evaluating the possible transmission in California of food-borne zoonotic trematode parasites carried by the introduced snail Melanoides tuberculata (1R03AI156569-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10110457. Licensed CC0.

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