<![CDATA[Mumps is a viral infectious disease that primarily affects children and spreads easily among susceptible individuals and can be prevented through MMR vaccination, although it is not yet included in Indonesia’s national immunization program. Magelang City Health Office received a report of an increase in mumps cases on November 4, 2024, through the Early Warning and Response System (SKDR). Mumps transmission occurred within the Elementary School 4 Magelang cluster. An outbreak investigation was important to determine the magnitude of the problem and the factors that contributed to the occurrence of mumps. The research design employed a 1:4 case-control study involving all 12 identified mumps cases and 48 controls from a total population of 114. Cases were defined as students experiencing clinical symptoms of mumps, specifically posterior jaw pain and/or parotid gland swelling, or who were diagnosed by medical personnel. Data collection was conducted using interviews with the students and parents, observations, and case report data. The data were analyzed using bivariate analysis with the chi-square test. Twelve cases were reported in total, beginning with the first case on September 25, 2024, and peaking between November 5–11. The highest attack rate was observed among male students (14.06%), students aged 6–7 years (19.23%), and first-grade students (20%). The most common symptom was posterior jaw pain (100%), and the most common risk factors were a history of contact with patients (66.7%) and a history of travel (33.3%). Bivariate analysis revealed that sharing eating and drinking utensils (p-value 0.006) and travel history (OR = 11.5; 95% CI: 1.79–73.58) were significantly associated with mumps occurrence. However, other factors such as MMR vaccination status, history of contact with patients, and current illness status were not statistically significant. Schools should collaborate with healthcare facilities to strengthen infectious disease surveillance and prevent further cases.Keywords: Mumps, Disease Outbreak, School Health Service, Travel History, Outbreak Investigation, Case-control Studies.]]>
