TB burden higher in vulnerable populations vs general populations

Vulnerable populations face a substantially higher burden of tuberculosis (TB) than general populations face, according to systematic review findings published in The Lancet Infectious Diseases.

Investigators sought to evaluate the prevalence and incidence of tuberculosis among global vulnerable populations. The goal was to underline the best available evidence to inform decision making. Vulnerable populations studied included miners, people experiencing homelessness, nomadic populations, incarcerated populations, sex workers, indigenous people, men who have sex with men, people living in slum settings, transgender individuals, people who use drugs, people living with HIV, and refugees (asylum seekers, internally displaced people, and undocumented migrants).

A systematic review and overview of reviews was conducted using the Cochrane Library, MEDLINE, and Embase databases from January 2010 to March 2023. The investigators searched for reviews and articles published in Chinese, French, and English reporting on the incidence or prevalence of active tuberculosis among the 12 prespecified vulnerable populations. If eligible reviews were lacking for any given population, then observational and experimental studies were considered for inclusion.

Overall, the investigators included 44 publications (23 reviews and 21 primary studies) in their review. Methodological quality and the comprehensiveness of the evidence varied across populations. The quality of included reviews was low or critically low in 20/23 review publications.

Pooled estimates were available for less than half of the 12 groups studied, comprehensively reported for asylum seekers, refugees, people living with HIV, and incarcerated individuals. Among these groups, incarcerated populations had the highest pooled prevalence of TB (about 2500 cases/100,000 people). Refugees had a 4-times greater increase in tuberculosis prevalence compared with asylum seekers and a prevalence ratio of 130 compared with indigenous populations.

Prevalence reported over all vulnerable populations was about 1000 cases/100,000 people. Among refugees and asylum seekers, pooled TB prevalence was 1331 cases/100,000 people; reported prevalence by continent was 1458/100,000 for Europe, 1080/100,000 for the Americas, and 860/100,000 for Asia.  In pooled estimates, asylum seekers, refugees, people living with HIV, incarcerated individuals, and people experiencing homelessness often had prevalence ratios greater than 25 compared with the general population. A single review reported prevalence ratios ranging from 22 (Sweden) to 461 (United States).

The best-available incidence ratios were noted among individuals who were incarcerated, but generally were reported infrequently. Incidence rates ranged from 31 cases to 900 cases/100,000 and almost exclusively from studies conducted in the US. Pooled incidence varied regionally, ranging from 30 cases in North America to 2190 cases/100,000 in Africa. The highest incidence ratio was in South America (26.9).

A dearth of evidence was found for transgender individuals, men who have sex with men, sex workers, nomadic populations, and miners.

Review limitations include the potential for unreliable data comparisons due to differences in population characteristics and local context, heterogeneity, and logistical differences in tuberculosis screening.

The investigators concluded, “The burden of tuberculosis is substantially higher among vulnerable populations than general populations, suggesting a need for improved integration of these groups, including dedicated efforts for their identification, targeted screening and prevention measures, as well as treatment support.”

References:

Litvinjenko S, Magwood O, Wu S, Wei X. Burden of tuberculosis among vulnerable populations worldwide: an overview of systematic reviews. Lancet Infect Dis. Published online September 8, 2023. doi:10.1016/S1473-3099(23)00372-9

Source: Pulmonology Advisor Update