Nipah Virus Infection in Kozhikode, Kerala, South India, in 2018: Epidemiology of an Outbreak of an Emerging Disease

BACKGROUND: An outbreak of the rare and highly pathogenic Nipah virus infection occurred in Kozhikode, Kerala, India, during May 2018. METHODOLOGY: Outbreak control activities included laboratory case confirmation and isolation. Contact surveillance was initiated and close contacts were home quarantined for the maximum incubation period of the disease. Field visits and verbal autopsy of the deaths were done to elicit the details of exposure. RESULTS: Of the 18 confirmed cases, 16 succumbed (case fatality rate, 88.8%). The mean incubation period was 9 days. The transmission was person to person wherein the primary case served as a point source for 15 other cases including 2 health-care workers. The mean age of the affected cases was 41 years with male preponderance. More than 2600 contacts were under surveillance. The outbreak was contained within 3 weeks and declared closed by July the same year. CONCLUSION: Early detection of the outbreak and prompt isolation of cases along with strengthening of infection control practices and barrier nursing helped in containing the outbreak.