Better understanding extrapulmonary tuberculosis: A scoping review of public health impact in Pakistan, Afghanistan, India, and Bangladesh.

Background and Aims: South Asian countries, including Pakistan, Afghanistan, India, and Bangladesh, have a high prevalence of pulmonary and extra-pulmonary tuberculosis (EPTB). This prevalence is influenced by various risk factors such as ethnicity, nutrition, socioeconomic disparities, high out-of-pocket healthcare expenses, and specific Mycobacterium Tuberculosis (TB) lineages. The COVID-19 pandemic has likely hindered access to healthcare and led to under-reporting of EPTB cases nationally and internationally. This rapid review aimed to summarize the literature on the prevalence and disease outcomes of EPTB in the mentioned countries, compare the situations across countries, and provide recommendations for future action. Methods: The review utilized PubMed and Google Scholar databases to search for literature on EPTB in South Asian countries. The search string included keywords related to different forms of EPTB and the countries of interest while excluding pulmonary tuberculosis. Results: The results showed that both TB, including drug-resistant TB, and EPTB are prevalent and burdensome in South Asia. In Pakistan, pleural TB was the most commonly reported form of EPTB, followed by lymph node TB, abdominal TB, osteoarticular TB, Central Nervous System TB, and miliary TB. In India, lymph node TB(LNTB) was more common among EPTB cases. Bangladesh reported a high prevalence of EPTB involving lymph node, pleura, and abdomen, while Afghanistan had a higher prevalence of forms such as LNTB and tuberculous meningitis. Conclusion: In conclusion, the prevalence of EPTB in Pakistan, Afghanistan, India, and Bangladesh is alarmingly high and negatively impacts population health. Effective measures are needed for treatment and management of this condition, along with addressing current and future challenges. Strengthening the evidence base through surveillance and research is crucial to understand the patterns and significant factors related to EPTB, requiring investment in these areas.