Outbreak Investigation of Influenza in Pajaru VDC of Jajarkot District of Nepal.

BACKGROUND: An outbreak investigation study was conducted in Pajaru, one of the initially affected Village Development Committees (VDCs) of the Jajarkot district in Nepal following an outbreak of respiratory illness in early 2015. The objectives of this study were to identify the cases and magnitude of the outbreak. METHODS: A cross-sectional study was carried out in mid-April 2015 covering five most affected wards of Pajaru VDC to assess the patients using standard case definition for Influenza like Illness (ILI). Throat and nasal swabs were collected and sent to the National Influenza Center (NIC) in Kathmandu for laboratory confirmation. RESULTS: The throat swab samples tested at NIC found Influenza A H1N1 pdm09. The attack rate was calculated to be 3% in ward number 9 and 41% in ward number 8. Wavelength of the infection was nearly two weeks in both the wards. Nearly 54% of the specimens were positive for Influenza A H1N1 pdm09. There was no ILI case fatality in the study area. Children aged 0-15 years were most affected. Majority of the patients presented with symptoms of fever, cough and sore throat. CONCLUSIONS: There was gradual decline in the number of cases in all five wards suggestive of development of natural immunity in the community. True severity of the outbreak was not accurately reflected as compared to media reports.