Men develop tuberculosis at substantially higher rates than women worldwide, a pattern that has held across countries with very different health systems for decades. New pooled research suggests the gap is more about how often men become infected in the first place than about what happens after infection takes hold.
The analysis, published in the journal eClinicalMedicine and led by scientists at University College London's Institute for Global Health, drew on 11 prospective cohort studies conducted in sub-Saharan Africa, Europe, Asia, and South America. Together, they included 22,424 participants enrolled in studies running from 2005 through 2017, with an average follow-up of 2.8 years per participant. At baseline, 38.1% of males and 35.0% of females were infected. After adjusting for age, males had a 12% higher likelihood of infection, according to CIDRAP.
The scale of what is being explained is substantial. An estimated 10.7 million people worldwide developed tuberculosis in 2024, 5.8 million of them men and 3.7 million women.
The Design Behind the Finding
Prospective cohorts follow people forward in time, which allows researchers to separate two questions that are usually tangled together in cross-sectional data. The first is whether men encounter the bacterium more often. The second is whether, once infected, men are more likely to progress to active disease.
On the second question, the analysis found no significant difference. Among participants who tested positive for infection at the start, tuberculosis disease occurred at 15.6 cases per 1,000 person-years in males and 16.3 per 1,000 person-years in females, a gap that was not statistically significant. Among those who initially tested negative, future risk did not differ significantly either.
Separating those two questions matters because they imply different responses. If exposure is the driver, the answer lies in where and how people are screened, and in finding infectious cases sooner. If progression is the driver, the answer lies in biology and in offering preventive treatment to people already carrying a latent infection. The two are not mutually exclusive, and most programs pursue both, but resources are finite, and balancing them is a real decision.
The researchers were careful about how far the finding stretches. They did not measure social interactions, occupational exposures, or behavioral risks, any of which could explain why men are infected more often, and they noted that healthcare-related and clinical factors may account for part of the difference. Their own summary is that the higher burden among males "is likely to reflect multiple mechanisms rather than a single pathway," and they say their data cannot rule out biological differences in susceptibility. A recent review has highlighted possible roles for sex hormones, chromosomes, and immune responses in progression and outcomes. This analysis narrows the picture without closing it. Co-lead author Yohhei Hamada said in a university news release that reducing inequalities in exposure among men may do more to narrow the gap than interventions aimed only at progression.
Symptom-Based Screening May Be the Weak Link
A separate line of evidence points to the tools health systems use to find cases. A systematic review in PLOS Medicine covering 102 prevalence surveys in low- and middle-income countries found that symptom reporting itself differs by sex, which the authors described as a sex differential measurement mechanism.
The practical implication is uncomfortable. Screening approaches that depend on someone reporting a cough or fever may systematically underdetect tuberculosis in men, who report symptoms less readily and engage with care later. Delayed diagnosis then extends the period during which someone is infectious, which feeds back into the exposure gap identified by the cohort analysis.
That review also found an association between higher male HIV prevalence relative to females and higher male-to-female tuberculosis prevalence ratios, another thread that complicates any single explanation.
Behavioral and structural factors are frequently raised in this literature, though neither analysis measured them directly. Higher rates of smoking, alcohol use, and diabetes among men in many settings are established risk factors for tuberculosis, and occupational settings such as mining and construction concentrate exposure. These remain plausible contributors rather than quantified ones.
Relevance for Patients in the United States
Tuberculosis is not a distant problem here. United States cases reached their highest annual total in more than a decade in 2024 and remain elevated, with provisional 2025 data showing 10,260 cases, a rate of 3.0 per 100,000, and a 1 percent decline from the year before. Adults 65 and older were the only age group whose case count rose between those two years, according to the CDC's provisional data report. Seventy-seven percent of cases were in people born outside the United States.
The groups carrying the most risk domestically are people born in countries with high tuberculosis burden, older adults, people with diabetes or HIV, people receiving immunosuppressive medications, and residents and staff of congregate settings including shelters, nursing homes, and correctional facilities.
Symptoms of active pulmonary disease include a cough lasting three weeks or longer, coughing up blood or sputum, chest pain, fever, night sweats, unexplained weight loss, and fatigue. Anyone with a persistent cough and risk factors should ask a clinician specifically about tuberculosis testing rather than assuming a lingering respiratory infection. Latent infection produces no symptoms and is detected only through testing, which is why screening asymptomatic people in higher-risk groups matters.
Treatment is free or low-cost through local health departments in most jurisdictions, and shorter oral regimens have made completing therapy considerably more manageable than it once was. Nobody should stop tuberculosis medication early, since incomplete treatment is a principal driver of drug resistance.
The domestic trend is the reason this research is not purely a global health story. As MedicalDaily reported in its account of the recent national increase, the concern among public health officials is less about any single year's count than about the direction of travel and the state of the contact tracing and screening infrastructure meant to catch cases early.
The Questions the Analysis Leaves Open
The analysis does not identify a mechanism, establish causation, or change any current screening recommendations. It is observational pooled data, and the cohorts differed in setting, era, and methods.
What it does support is a question programs can address: whether screening strategies built around symptom reporting and clinic attendance are reaching men effectively, and whether active case finding in workplaces and other male-dominated settings would help close part of the gap. The World Health Organization publishes updated global figures annually, and further cohort work will be needed before any guidance changes. Readers should not expect a revision based on the strength of a single pooled analysis.
Key Questions Answered
What did the analysis find? Pooled data from 11 cohorts and more than 22,000 participants found that males had a 12 percent higher likelihood of tuberculosis infection after age adjustment, with no significant sex difference in progression to disease.
Does this prove biology plays no role? No. The researchers said the male burden likely reflects multiple mechanisms and that biological differences in susceptibility cannot be ruled out.
How large is the global gap? An estimated 10.7 million people developed tuberculosis in 2024, including 5.8 million men and 3.7 million women.
Why would screening miss men? Approaches that rely on people reporting symptoms may underdetect tuberculosis in men, who tend to report symptoms less readily and seek care later.
Is tuberculosis a problem in the United States? Yes. Cases hit their highest annual total in more than a decade in 2024, and provisional data for the following year showed 10,260 cases at a rate of 3.0 per 100,000.
What symptoms should prompt testing? A cough lasting three weeks or longer, coughing blood or sputum, chest pain, fever, night sweats, unexplained weight loss, and fatigue.
What does treatment cost? Testing and treatment are free or low-cost through local health departments in most jurisdictions. Treatment should never be stopped early without clinical guidance.
