# Exploiting the arthropod vector: novel mechanisms of Mycobacterium leprae transmission

> **NIH NIH R21** · UNIVERSITY OF SOUTH ALABAMA · 2024 · $231,000

## Abstract

PROJECT SUMMARY
 Hanson’s disease (HD), more commonly known as leprosy, is thought of as an ancient
disease that has been eradicated, yet in 2019, the number of new cases reported globally to the WHO
was more than 200,000. Up to 80% of the new leprosy cases presenting from around the world are
unable to relate ever having come in contact with another person who had leprosy. The lack of a
plausible biological contact source can provoke profound anxiety in newly diagnosed patients and
contributes to the stigmatization of leprosy as a mystical curse or punishment. In the United States,
armadillos are a large natural reservoir of Mycobacterium leprae and the same strain of bacteria
that circulates among armadillos also is responsible for 54% of the indigenous cases; thus, leprosy is
recognized as a zoonosis in the United States. It is realized that M. leprae is not stable in the
environment, so an intermediary host, such as an arthropod vector, may contribute to the
transmission of leprosy. The overall goal of this project is to determine the vector potential for blood-
feeding ticks to acquire and transmit infectious M. leprae to vertebrate hosts. Additionally, the
transcriptional activity of M. leprae in an arthropod host background will be compared to the M.
leprae transcriptome while in a vertebrate host. Combined, this project will potentially identify an
alternate route of leprosy transmission and the M. leprae molecules putatively associated with
this transmission cycle. The data generated from the proposed studies will greatly enhance our
understanding of the epidemiology of leprosy as it will be the first assessment of the biology of
M. leprae infection and transmission by Amblyomma ticks. Based on field surveys and experimental
evidence we suspect that Amblyomma ticks are competent vectors for M. leprae. Tick vector
competence for M. leprae has not been thoroughly explored under controlled laboratory conditions
previously, so the relevance of the findings from this project will provide novel information that can be
related to the ecology and epidemiology of leprosy.

## Key facts

- **NIH application ID:** 10746137
- **Project number:** 5R21AI173708-02
- **Recipient organization:** UNIVERSITY OF SOUTH ALABAMA
- **Principal Investigator:** Kevin R. Macaluso
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $231,000
- **Award type:** 5
- **Project period:** 2022-11-28 → 2025-10-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10746137

## Citation

> US National Institutes of Health, RePORTER application 10746137, Exploiting the arthropod vector: novel mechanisms of Mycobacterium leprae transmission (5R21AI173708-02). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10746137. Licensed CC0.

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