# Air Pollution Effects on Transmission of Mycobacterium tuberculosis in Urban Slum Community in Uganda

> **NIH NIH R01** · RUTGERS BIOMEDICAL AND HEALTH SCIENCES · 2022 · $572,621

## Abstract

Air pollution and tuberculosis (TB) represent two of the most devastating and life-threatening global public health
problems. With hundreds of million persons living in urban slums worldwide, vulnerable, marginalized and hard-
to-reach populations are most affected by indoor and outdoor air pollution and Mycobacterium tuberculosis (Mtb)
transmission. This project explores if and how air pollution fine particulate matter (PM2.5) exposure increases the
transmission of Mtb from TB index cases to their household contacts (HC) in a high TB incidence urban slum
area (Namuwongo) in Kampala/Uganda. We have previously shown that air pollution PM2.5 exposures suppress
essential, protective, Mtb-specific, human innate and adaptive host immune responses. A key unanswered
question of great significance to global TB control efforts is whether air pollution exposure increases the risk for
transmission of Mtb in vulnerable communities, both through increased infectiousness (of the TB index cases)
and susceptibility to Mtb infection (of their contacts). We hypothesize that inhalational exposure to PM2.5
increases the infectiousness of TB index cases by increasing their source strength i.e. the Mtb content in their
respiratory aerosols, and by triggering cough. We further hypothesize that PM2.5 exposure suppresses protective
immune responses leading to increased susceptibility to Mtb infection in the HC of the TB index cases. Both
would be expected to increase transmission of Mtb in the community. To address our hypotheses, we will
evaluate (1) the source strength of TB index cases and new Mtb infection in their HC (Mtb transmission) (SA1),
(2) personal air pollution (PM2.5) exposures (SA2) and (3) how personal air pollution (PM2.5) exposure is
associated with PM load in airway macrophages, source strength, and Mtb transmission to HC (SA3). To assess
the source strength of the TB index cases, we will quantify the Mtb load in their respiratory aerosols using a
novel face mask sampling approach. We will also determine TB index case cough frequencies with the Leicester
Cough Monitor, assess chest radiographs and time to culture positivity (MGIT culture). Transmission of Mtb from
TB index cases to HC will be ascertained by tuberculin skin test and QFN-Plus blood test between weeks 0 and
8. All measures combined reflect infectiousness of TB index cases. Exposure to PM2.5 of TB index cases and a
random sample of HC will be studied using multiple approaches: `gold standard' gravimetric (UPAS) and real-
time air monitoring between weeks 0 and 8, assessment of PM load in airway macrophages obtained by sputum
induction of TB index cases and in randomly selected as well as newly Mtb-infected HC, stationary household
PM2.5 and outdoor PM2.5 monitoring, and household study with questionnaires. Associations between TB index
case source strength, Mtb transmission and PM2.5 exposure will be sought using linear modeling, to identify both
main effects and modifying factors. Deciphe...

## Key facts

- **NIH application ID:** 10367013
- **Project number:** 2R01ES020382-07A1
- **Recipient organization:** RUTGERS BIOMEDICAL AND HEALTH SCIENCES
- **Principal Investigator:** STEPHAN K SCHWANDER
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $572,621
- **Award type:** 2
- **Project period:** 2012-09-15 → 2028-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10367013

## Citation

> US National Institutes of Health, RePORTER application 10367013, Air Pollution Effects on Transmission of Mycobacterium tuberculosis in Urban Slum Community in Uganda (2R01ES020382-07A1). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10367013. Licensed CC0.

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