Prevalence of active pulmonary tuberculosis in Hainan, China: a population-based, cross-sectional survey

BACKGROUND: Hainan Province, the only tropical province in China, remains a high-burden area for tuberculosis (TB). However, up-to-date data on the prevalence and demographic disparities of TB cases are lacking. To address these gaps, we conducted a population-based TB prevalence survey.

We conducted a population-based, cross-sectional survey using a multistage stratified random cluster sampling design. The study included adults (aged ≥15 years) who had resided in their households for at least six months in Hainan. Screening and diagnostic procedures followed World Health Organization (WHO) guidelines. We calculated the crude prevalence of active PTB among participants with valid results and applied inverse probability weighting combined with multiple imputation to account for missing data. Prevalence estimates were compared by rural-urban residence, age group, sex, and ethnicity.

In 2023, a total of 67,681 individuals were enumerated, of whom 35,219 (52.0%) were eligible for the survey. Among them, 33,778 (95.9%) participated. We identified 144 cases of active PTB, including 21 smear-positive and 36 bacteriologically confirmed cases. The weighted prevalence of active PTB was 355 (95% CI 291-418) per 100,000 population. The prevalence of smear-positive PTB was 63 (95% CI 36-90) per 100,000, and bacteriologically confirmed PTB was 96 (95% CI 63-129) per 100,000. Of the 144 active PTB cases, 120 (83.3%) were male, 62 (43.1%) were aged 60 or above, and 55 (38.2%) were re-treated cases. Notably, 85 (59.0%) of all active PTB cases and 17 (47.2%) of bacteriologically confirmed cases reported no TB-related symptoms. Both proportions are substantially higher than those reported in the 2010 national survey (43.1% and 14.2%, respectively).

Although the prevalence of active PTB in Hainan has declined significantly since 2010, it remains higher than in other parts of China. Marked disparities were observed by sex, age, geographic region, and ethnicity. Particular attention should be directed toward men aged 45 years and above, the Li ethnic group, and rural populations. The high proportion of re-treated cases and asymptomatic patients underscores the need to enhance treatment quality and strengthen active case-finding strategies to accelerate TB elimination efforts in Hainan Province.