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.