# Characterizing infectiousness of subclinical TB and identifying novel early diagnostic strategies for preventing transmission

> **NIH NIH R01** · STANFORD UNIVERSITY · 2021 · $153,373

## Abstract

Project Summary
Tuberculosis remains the leading cause of death by an infectious disease worldwide,
despite the widespread availability of effective therapy. Two major scientific knowledge
gaps constrain our ability to effectively respond this epidemic: 1) understanding
characteristics of individuals who are transmitting infection within the population; and 2)
identifying efficient means of diagnosing these individuals early in their course of disease
to prevent ongoing transmission. Our preliminary research and that of others has
demonstrated that, for any given time in a population, a substantial proportion of
individuals with microbiologically confirmed tuberculosis have few or no classical
symptoms. This state has been described as “subclinical tuberculosis”. What fraction of
cases are subclinical, how infectious these individuals are, and the total contribution of
subclinical tuberculosis towards transmission in the population is poorly understood. This
proposal leverages our unique research infrastructure in prisons in Central-Western
Brazil to evaluate novel tools, including a disposable mask to capture exhaled
bioaerosols, for early detection of tuberculosis in asymptomatic individuals. We will test
the following hypotheses: 1) individuals with tuberculosis who lack symptoms are on
average at least 50% as infectious as those with symptoms, and contribute equally to
overall transmission; 2) mask aerosol sampling will be more effective than sputum
testing for tuberculosis diagnosis in individuals with few or no symptoms; 3) biannual
mass screening with diagnostics targeted at subclinical tuberculosis would be cost-
effective in prisons. Overall, this project will address fundamental questions about
tuberculosis transmission, while testing practical approaches to control tuberculosis in
high burden settings.

## Key facts

- **NIH application ID:** 10125940
- **Project number:** 5R01AI149620-02
- **Recipient organization:** STANFORD UNIVERSITY
- **Principal Investigator:** Jason Randolph Andrews
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $153,373
- **Award type:** 5
- **Project period:** 2020-03-11 → 2024-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10125940

## Citation

> US National Institutes of Health, RePORTER application 10125940, Characterizing infectiousness of subclinical TB and identifying novel early diagnostic strategies for preventing transmission (5R01AI149620-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10125940. Licensed CC0.

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