Measles outbreak among unvaccinated children in Bajura

Introduction: Measles outbreak occurs when there are three or more laboratory confirmed measles cases in a village in a period of one month. Integrated surveillance system has helped to identify the measles outbreak, to characterize its epidemiology and to timely respond it. Methods: This is a descriptive study of measles outbreak that occurred in Bajura district in February to March 2010. The epidemiological characteristics of the outbreak are described. The outbreak was investigated from 4-8 March 2010 with necessary epidemiological information and biological specimen collection. One month follow up was done to determine the clinical outcome of the measles cases. Results: A total of 36 people had measles; 97% of them were under 15 years of age and 89% had not been immunized with measles vaccine. Attack rate and vaccine efficacy was 23% and 50% amongst children less than 15 years of age and case fatality rate (CFR) was 3%. Biological samples were collected from 11 patients; all of which tested IgM positive for measles and genotype D8 was isolated. Conclusions: CFR of this outbreak is higher than the national CFR. Vaccine efficacy of 50% points towards the need for investigation of vaccine logistics and cold chain system. Moreover, this laboratory test confirmed an outbreak showing that the measles virus could be imported from an endemic region and rapidly spread through a susceptible population who were previously not immunized.