# Schistosomiasis at the edge of elimination: characterizing sources of new infections in residual transmission hotspots

> **NIH NIH R01** · UNIVERSITY OF COLORADO DENVER · 2020 · $712,522

## Abstract

PROJECT SUMMARY/ABSTRACT
Schistosomiasis, a waterborne infection that affects approximately 200 million people, persists in some areas
despite aggressive control measures, for reasons that are not well understood. Hotspots of schistosomiasis
persistence and reemergence have been documented in parts of China and, more recently, sub-Saharan
Africa. These hotspots threaten to disrupt global targets for schistosomiasis elimination, and highlight the need
to understand the origins of new infections in these areas to improve control strategies. Plausible infection
sources include human hosts within a community, other mammalian species, and imported infections via, for
example, mobile human hosts. However, the actual contributions of such sources to the sustained
transmission of complex macroparasites such as schistosomiasis in areas under control pressure is poorly
resolved. Genomic tools offer the potential to discern detailed transmission pathways, even for highly inbred
parasites such as schistosomes. The proposed research leverages genomic approaches and longitudinal
epidemiological data to identify origins of new infections in transmission hotspots. High-resolution sequencing
and analysis methods for Schistosoma japonicum will be used to infer parasite ancestry across generations,
allowing identification of hosts that serve as infection sources. Over ten years of longitudinal data from
southwest China, and ongoing access to schistosomiasis hotspots will be used to characterize host and
village-level characteristics that predict the contribution of distinct hosts and the contributions of parasite import
to transmission. Specifically, the three proposed aims will evaluate evidence that high transmission human
hosts (superspreaders) serve as sources of new infections (Aim 1), identify the conditions that facilitate the
contributions of non-human hosts to infection (Aim 2), and test for and identify if present key pathways of
parasite import (Aim 3). The ambitious goals for the control of schistosomiasis and other neglected tropical
diseases and the persistence of the disease in transmission hotspots despite control measures highlights the
need for new approaches to prevent transmission. By determining the extent to which new infections are
coming from human hosts, animal hosts, or movement between villages, it will be possible to fine-tune control
efforts to focus on key sources of infection in areas approaching elimination.

## Key facts

- **NIH application ID:** 9828058
- **Project number:** 5R01AI134673-02
- **Recipient organization:** UNIVERSITY OF COLORADO DENVER
- **Principal Investigator:** Elizabeth Carlton
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $712,522
- **Award type:** 5
- **Project period:** 2018-11-23 → 2023-10-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9828058

## Citation

> US National Institutes of Health, RePORTER application 9828058, Schistosomiasis at the edge of elimination: characterizing sources of new infections in residual transmission hotspots (5R01AI134673-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9828058. Licensed CC0.

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