Resurgence of measles in Bosnia and Herzegovina amid declining vaccination coverage
Background: Sarajevo Canton reported large measles outbreaks in 2019 and 2024, highlighting the impact of the persistent gaps in immunisation coverage. Aim: To analyse 2 measles outbreaks in Sarajevo Canton in Bosnia and Herzegovina, identify populations at risk and assess the impact of vaccination coverage on disease transmission. Methods: We collected publicly available weekly case counts data for 45 weeks from the Public Health Institute of Sarajevo Canton and examined the vaccination coverage for 5 years to assess the impact of immunisation on outbreak dynamics. We conducted descriptive analyses using RStudio version 2024 and evaluated the differences between outbreaks using Mann-Whitney U test. P < 0.05 was considered statistically significant. Results: A total of 869 cases were reported in 2019 and 4505 in 2024, and children aged 1–4 years were mostly affected (42.1%). Most of the cases were either unvaccinated or had unknown vaccination status; 92.3% of cases in 2019 were unvaccinated, and 87.7% in 2024 were unvaccinated, while 9.9% had unknown vaccination status. The 2024 outbreak had a higher and longer peak (416 vs 91 cases) occurence than 2019, and one death was reported in each year. Conclusion: The declining vaccination coverage in Sarajevo Canton contributed to increased measles incidence. Strengthening mandatory immunisation, targeted catch-up campaigns and public communication are essential to achieve herd immunity, prevent future outbreaks and progress towards Universal Health Coverage.