Measles outbreak investigation in Basso Liben District, Amhara Region, Ethiopia 2017

Measles is an acute, highly contagious viral disease caused by measles virus and transmitted primarily by respiratory droplets or airborne spray to mucous membranes in the upper respiratory tract or the conjunctiva. Measles is one of vaccine preventable diseases but the virus usually causes outbreaks especially among unvaccinated population.  The aim of this study was to investigate the outbreak and identify associated factors in Basso Liben district in Ethiopia.  An unmatched case control study was conducted to investigate measles outbreak from 90 study subjects (30 cases and 60 controls). Face to face interview was conducted using structured questionnaire. Epi info version 7 was used for data entry and analyzed using SPSS version 20 software. Logistic regression was employed to identify factors associated with measles outbreak with 95% confidence level and statistical significance was declared at p-value <0.05.  The total attack rate of measles was found to be 1.24 per 1,000 population in Basso Liben district. The highest age specific attack rate was seen in under- one age groups (4.76 per 1,000 children), and the next was in age groups 1- 4 years old   (3.28 per 1000 population). In multivariate logistic regression, contact history with measles case AOR=8.132 (95% CI 2.047, 32.297) and presence of measles case in the neighbor (AOR= 6.928; 95% CI 1.37, 29.12) were risk factors for contracting measles. But previous history of measles case (AOR= 0.10; 95% CI 0.02, 0.56) and vaccinated with measles vaccine AOR=0.11 (95%CI 0.021, 0.573) were protective associated factors for measles.  Key words: Measles, outbreak, Basso Liben, case control, Ethiopia.