Measles outbreak investigation in Kasoshekumer kebele, Sinana district, South-Eastern Oromia, Ethiopia: A case–control study

Abstract

Objective: This study aimed at verifying the outbreak, preventing further transmission, and identifying the risk factors for the outbreak. Method: A case–control study design was conducted from March 4, 2020 to April 30, 2020, in Kasoshekumer kebele of Sinana district. Thirty-seven carer–patient pairs and 74 controls were recruited in a 1:2 case–control ratio. Patients were selected using a national standard case definition of the Ministry of Health. Controls were selected from neighbors of patients and interviewed after the second incubation period from the last patient of the outbreak by a structured questionnaire similar to patients. All cases were included while controls were selected purposively for their exposure status. Vaccine efficacy, attack rate, and case fatality rate were conducted as a descriptive epidemiology. Multivariate analysis was used to identify associated factors. Result: Out of 109 study participants, there were 37 cases and 72 controls. The mean age was 58.8 months with ±54 standard deviation. Thirty-one (83.8%) of the cases had a known contact history and 23 (62.2%) were unvaccinated. The age-specific attack rate was 36/1000 in <5 years and 53/100,000 in >15 years. The estimated vaccine efficacy was 73.7%. Having any type of socialization behavior (adjusted odds ratio = 6.8, confidence interval: 4.25, 11.4), maternal poor knowledge of measles prevention (adjusted odds ratio = 4.152, confidence interval: 1.226, 8.058), and being unvaccinated (adjusted odds ratio = 7.79, confidence interval: 2.281, 12.63) were associated factors for measles infection. Conclusion: Poor knowledge of the parents on vaccination and the less effort taken to deliver good attitude toward vaccination are resulting in measles outbreak. However, herd immunity can prevent the outbreak; if not, the community will continue to suffer from mortality and morbidity. A resilient immunization program with sustainable and equitable supply, delivery, monitoring, and evaluation is a fundamental action in prevention of measles outbreak. Increased awareness of vaccination and other prevention measures are also crucial to end the outbreaks.