Sex Differences in Active Pulmonary Tuberculosis Outcomes in Mali, West Africa

Sex-based tuberculosis mortality in Newfoundland, 1900-1949: Implications for populations in transition

OBJECTIVE

During the second epidemiological transition, tuberculosis (TB) is one disease that declined substantially enough to reduce all-cause mortality. Sex-based differences in TB mortality may reveal an important dimension of population health transitions between the urbanizing and rural regions of Newfoundland.

MATERIALS AND METHODS

For the island of Newfoundland, yearly age-standardized sex-based TB mortality rates were calculated using individual death records from 1900 to 1949 (n = 30 393). Multiple linear regression models predict the relative rates (RR) of sex-based mortality and the absolute difference between males and females while controlling for time and region (the urbanizing Avalon Peninsula or rural Newfoundland). Multiple linear regression models also predict the median age at death from TB while controlling for time, region, and sex to assess if TB was shifting to an older adult disease compared to those typically afflicted in ages 20-44.

RESULTS

Female TB mortality was relatively and absolutely higher than males; additionally, RR and absolute differences between male and female mortality were significantly lower in rural Newfoundland than the Avalon Peninsula. Median age at death for males was significantly higher than females, and differences in median age at death increased over time.

DISCUSSION

The historically high prevalence of TB throughout Newfoundland, including domestic, social, and public health responsibilities of women, likely contributed to increased exposure and transmission, leading to higher observed mortality. Sex-based TB outcomes should be considered in the discussion of the progression of the epidemiological transition as dynamic inequalities that do not necessarily fit contemporary generalizations of sex-based TB epidemiology.

Relationship between patient sex and anatomical sites of extrapulmonary tuberculosis in Mali

Background

Contribution of host factors in mediating susceptibility to extrapulmonary tuberculosis is not well understood.

Objective

To examine the influence of patient sex on anatomical localization of extrapulmonary tuberculosis.

Methods

We conducted a retrospective cross-sectional study in Mali, West Africa. Hospital records of 1,304 suspected cases of extrapulmonary tuberculosis, available in TB Registry of a tertiary tuberculosis referral center from 2019 to 2021, were examined.

Results

A total of 1,012 (77.6%) were confirmed to have extrapulmonary tuberculosis with a male to female ratio of 1.59:1. Four clinical forms of EPTB predominated, namely pleural (40.4%), osteoarticular (29.8%), lymph node (12.5%), and abdominal TB (10.3%). We found sex-based differences in anatomical localization of extrapulmonary tuberculosis, with males more likely than females to have pleural TB (OR: 1.51; 95% CI [1.16 to 1.98]). Conversely, being male was associated with 43% and 41% lower odds of having lymph node and abdominal TB, respectively (OR: 0.57 and 0.59).

Conclusion

Anatomical sites of extrapulmonary tuberculosis differ by sex with pleural TB being associated with male sex while lymph node and abdominal TB are predominately associated with female sex. Future studies are warranted to understand the role of sex in mediating anatomical site preference of tuberculosis.

Sex and Gender Differences in Tuberculosis Pathogenesis and Treatment Outcomes

Tuberculosis remains a daunting public health concern in many countries of the world. A consistent observation in the global epidemiology of tuberculosis is an excess of cases of active pulmonary tuberculosis among males compared with females. Data from both humans and animals also suggest that males are more susceptible than females to develop active pulmonary disease. Similarly, male sex has been associated with poor treatment outcomes. Despite this growing body of evidence, little is known about the mechanisms driving sex bias in tuberculosis disease. Two dominant hypotheses have been proposed to explain the predominance of active pulmonary tuberculosis among males. The first is based on the contribution of biological factors, such as sex hormones and genetic factors, on host immunity during tuberculosis. The second is focused on non-biological factors such as smoking, professional exposure, and health-seeking behaviors, known to be influenced by gender. In this chapter, we review the literature regarding these two prevailing hypotheses by presenting human but also experimental animal studies. In addition, we presented studies aiming at examining the impact of sex and gender on other clinical forms of tuberculosis such as latent tuberculosis infection and extrapulmonary tuberculosis, which both appear to have their own specificities in relation to sex. We also highlighted potential intersections between sex and gender in the context of tuberculosis and shared future directions that could guide in elucidating mechanisms of sex-based differences in tuberculosis pathogenesis and treatment outcomes.