Age-specific hospitalization dynamics during a measles outbreak in Nyanza District, Southern Province, Rwanda, 2026:...

Measles remains a leading cause of vaccine-preventable mortality, particularly in low- and middle-income countries. Despite Rwanda's high routine immunization coverage and introduction of a two-dose measles-rubella schedule, persistent immunity gaps continue to drive localized outbreaks. Understanding how age influences hospitalization duration during outbreaks is critical for optimizing clinical management and resource allocation, yet evidence using robust time-to-event methods remains limited.

We conducted a retrospective cohort analysis of 56 confirmed measles cases identified during an outbreak in Nyanza District, Southern Province, Rwanda (February 16 to April 17, 2026). Demographic, clinical, and geographic data were extracted from routine surveillance records. Kaplan-Meier survival curves described time to hospital discharge stratified by age group.

Among the 56 cases, infants under 9 months formed the largest proportion (44.6%), followed by adults over 15 years (25%). Geographic clustering was concentrated in Busasamana sector (51.7%). Age significantly predicted hospitalization duration (log-rank P = 0.00049), with children aged 5-15 years demonstrating the most rapid discharge by day 5, while infants under 9 months.

Age was a significant determinant of measles hospitalization duration, with infants and adolescents experiencing the most prolonged clinical courses while school-aged children recovered fastest. These findings support age-targeted clinical triage and resource planning during measles outbreak response.