Estimating the population at high risk for tuberculosis through household exposure in high-incidence countries: a model-based analysis

Abstract

Background Household contacts of people with pulmonary tuberculosis (TB) have greater risk of developing TB. Recent guidelines conditionally recommended TB preventive treatment (TPT) for household contacts of any age living in TB high-incidence countries, expanding earlier guidance to provide TPT to household contacts under five. The all-age population of household contacts has not been estimated. Methods Our model-based estimation included 20 countries with >80% of incident TB globally in 2019. We developed country-specific distributions of household composition by age and sex using bootstrap resampling from health surveys and census data. We incorporated age-, sex-, year-, and location-specific estimates of pulmonary TB incidence from the Global Burden of Diseases, Injuries, and Risk Factors Study 2019 to estimate the population in each country sharing a household with someone with incident pulmonary TB, and quantified uncertainty using a Monte Carlo approach. Findings We estimate that 38 million [95% uncertainty interval (UI) 33- 43 million] individuals lived in a household with someone with incident pulmonary TB in 2019 in these 20 countries. Children under five made up 12% of the population with household exposure, while adults were 65%. Zimbabwe, Mozambique, Zambia, and Pakistan had the highest proportion of the population with household exposure, while India had the highest number of contacts (11·4 million, 95% UI 9·7-13·4 million). Interpretation Expanding TPT evaluation to household contacts of all ages in high-incidence countries could include a population more than 7-times larger than the under-5 contacts previously prioritized. This would substantially increase the impact of household contact investigation on reducing TB morbidity and mortality. Funding JMR is supported by the National Institute of Allergy and Infectious Diseases (K01 AI138620). This research was funded in part by a 2020 developmental grant from the University of Washington / Fred Hutch Center for AIDS Research, an NIH funded program under award number AI027757 which is supported by the following NIH Institutes and Centers: NIAID, NCI, NIMH, NIDA, NICHD, NHLBI, NIA, NIGMS, NIDDK. This work was funded in part by the National Science Foundation (DMS-1839116).

Tuberculosis transmission in Households of Pulmonary Tuberculosis Patients with Alcohol use in the Puducherry Region

“…A modelling study was conducted to estimate the number of people in this high-risk category, which included 20 countries with >80% of incident TB globally in 2019 11 . India was found to have the largest number of HHC exposed to incident pulmonary TB, with an estimated 114 million people (95% UI 97-134), the overall estimate of HHC with exposure globally being 38 million (95% UI 33 to 43 million) 12 .…”

Transcriptional profiling of human peripheral blood mononuclear cells in household contacts of pulmonary tuberculosis patients provides insights into mechanisms of Mycobacterium tuberculosis control and elimination

“…This study recruited HHCs of patients with ATB as the study subjects. The overall incidence rate of active disease in household contacts was estimated to be 11.0 per 1000 person-years [ 16 ], with the majority remaining asymptomatic without developing the active disease. These subjects’ immune systems may be able to control or eradicate the bacteria, despite repeated and prolonged exposure.…”

Spatio-temporal analysis of tuberculosis incidence in North Aceh District, Indonesia 2019-2021

“…This finding is in line with previous studies carried by Gwitira et al (2021) in Zimbabwe as well as Im in South Korea (2021). It occurred because of high population resulting in over-crowding that supported transmission of TB in the area (Aditama et al, 2019(Aditama et al, , 2020Noykhovich et al, 2019;Ross et al, 2021).…”