Outbreak Investigation of Mumps in a Rural Area of Patna District of Bihar, India.

Introduction: Mumps is an acute viral infection characterized by swelling of parotid or other salivary glands. In November, 2023, a clinical case of mumps was detected during a household visit in Ajwan village, Naubatpur block, Patna, which led to the investigation to determine a possible outbreak of mumps along with its epidemiology and to implement control measures. Methodology: House-to-house survey was conducted in localities with clustering of probable cases to gather necessary data using a structured questionnaire. The team provided medications to detected cases and conducted health awareness activities. The Integrated Disease Surveillance Programme unit, Patna, was alerted, and the line list of cases was shared. Specimens collected from eight active cases were "Reactive" for Mumps IgM antibody. Results: A total of 109 houses were surveyed, and 51 cases of mumps were detected with the majority (45.0%) between 6 and 10 years of age and a higher proportion of males (51.0%). The majority (56.9%) reported bilateral parotid gland swelling. None were immunized against mumps, and isolation was practiced by only 1 (2.0%). The majority visited local pharmacy for medication (68.6%), followed by unregistered practitioner/quack (11.8%). The overall attack rate of the outbreak was 6.36%, and the highest attack rate was observed in the 6-10 years age group (23.95%). Conclusion: The outbreak investigation findings emphasize the need for health awareness drives regarding mumps and the importance of isolation. With sporadic cases and cyclical outbreaks occurring regularly in India, introduction of the two-dose schedule of Measles-Mumps-Rubella in the national immunization schedule needs to be considered along with inclusion of mumps in the list of diseases under surveillance.