Trends in Tuberculosis Incidence and Mortality in South Africa and Bulgaria (2000–2023): The Impact of Income, Poverty, Unemployment, and Universal Health Coverage

BACKGROUND: Tuberculosis (TB) remains a major global public health challenge, with substantial variation across countries. South Africa has one of the highest TB incidence and mortality rates globally, while Bulgaria, a low-incidence country, faces a persistent TB burden among vulnerable populations. OBJECTIVES: To compare national trends in TB incidence and mortality in South Africa and Bulgaria from 2000 to 2023 and explore associations with selected socioeconomic indicators and health system coverage. METHODS: An ecological, descriptive, analytical study used national-level data from the WHO, World Bank, and official statistics. TB trends were analyzed alongside income, poverty, unemployment, and Universal Health Coverage indicators. Time series measures and Pearson correlation were used descriptively to summarize co-variation over time. RESULTS: Between 2000 and 2023, TB incidence declined by approximately 44% in the Republic of South Africa and 69% in Bulgaria. In both countries, TB incidence co-varied strongly with unemployment (RSA: r = 0.805; BG: r = 0.723). In Bulgaria, TB incidence was also strongly negatively associated with GDP per capita (r = -0.910), whereas no significant association with GDP was observed in South Africa. These findings indicate that TB trends co-varied more closely with labour market conditions in both contexts, while broader economic growth co-occurred with declining TB incidence only in Bulgaria. CONCLUSIONS: TB trends co-occurred with changes in socioeconomic conditions and health system coverage, with differing patterns across contexts. Findings highlight the relevance of equity-oriented, context-specific TB control strategies integrated with social and economic policies.