Jerry Hella1, Carl Morrow2, Francis Mhimbira1, Samuel Ginsberg3, Nakul Chitnis4, Sebastien Gagneux4, Beatrice Mutayoba5, Robin Wood2, Lukas Fenner6. 1. Ifakara Health Institute, Dar es Salaam, Tanzania; Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland. 2. Desmond Tutu HIV Centre, University of Cape Town, Cape Town, South Africa. 3. Department of Electrical Engineering, Faculty of Engineering and the Built Environment, University of Cape Town, Cape Town, South Africa. 4. Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland. 5. National Tuberculosis and Leprosy Program, Dar es Salaam, Tanzania. 6. Ifakara Health Institute, Dar es Salaam, Tanzania; Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland; Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland. Electronic address: lukas.fenner@ispm.unibe.ch.
Abstract
OBJECTIVES: For tuberculosis (TB) transmission to occur, an uninfected individual must inhale the previously infected breath. Our objective was to identify potential TB transmission hotspots in metropolitan city of Dar es Salaam, Tanzania and to model the annual risk of TB transmission in different locations of public importance. METHODS: We collected indoor carbon dioxide (CO2) data from markets, prisons, night clubs, public transportation, religious and social halls, and from schools. Study volunteers recorded social contacts at each of the locations. We then estimated the annual risks of TB transmission using a modified Wells-Riley equation for different locations. RESULTS: The annual risks of TB transmission were highest among prison inmates (41.6%) and drivers (20.3%) in public transport. Lower transmission risks were found in central markets (4.8% for traders, but 0.5% for their customers), passengers on public transport (2.4%), public schools (4.0%), nightclubs (1.7%), religious (0.13%), and social halls (0.12%). CONCLUSION: For the first time in a country representative of sub-Saharan Africa, we modelled the risk of TB transmission in important public locations by using a novel approach of studying airborne transmission. This approach can guide identification of TB transmission hotspots and targeted interventions to reach WHO's ambitious End TB targets.
OBJECTIVES: For tuberculosis (TB) transmission to occur, an uninfected individual must inhale the previously infected breath. Our objective was to identify potential TB transmission hotspots in metropolitan city of Dar es Salaam, Tanzania and to model the annual risk of TB transmission in different locations of public importance. METHODS: We collected indoor carbon dioxide (CO2) data from markets, prisons, night clubs, public transportation, religious and social halls, and from schools. Study volunteers recorded social contacts at each of the locations. We then estimated the annual risks of TB transmission using a modified Wells-Riley equation for different locations. RESULTS: The annual risks of TB transmission were highest among prison inmates (41.6%) and drivers (20.3%) in public transport. Lower transmission risks were found in central markets (4.8% for traders, but 0.5% for their customers), passengers on public transport (2.4%), public schools (4.0%), nightclubs (1.7%), religious (0.13%), and social halls (0.12%). CONCLUSION: For the first time in a country representative of sub-Saharan Africa, we modelled the risk of TB transmission in important public locations by using a novel approach of studying airborne transmission. This approach can guide identification of TB transmission hotspots and targeted interventions to reach WHO's ambitious End TB targets.
Authors: Rachel K Redmann; Deepak Kaushal; Nadia Golden; Breeanna Threeton; Stephanie Z Killeen; Philip J Kuehl; Chad J Roy Journal: J Aerosol Med Pulm Drug Deliv Date: 2021-10-06 Impact factor: 2.849