Rubella Outbreak Investigation at General Tadesse Biru Primary School, Addis Ababa, Ethiopia 2018

Abstract

Background: In African countries, rubella is widely under-recognized public health problem, and information on its epidemiology is very limited. In Ethiopia, rubella is not prioritized disease under surveillance and its vaccine has not been introduced into infant vaccination schedule. Rumor of suspected rubella outbreak received on January 26/2018. The purpose of investigation was to establish rumor existence, describe cases epidemiologically, identify causative agent and source of the outbreak to support outbreak control activities. Methods: A1:2 unmatched case-control study conducted at General Tadesse Biru Primary School, Addis Ababa, Ethiopia from February 3-25/2018. Total of 41 cases and 82 controls included. Controls selected conveniently from same school and data collected using structured questioner. Data analysis done using Epi-info software version7.2.1.0. Result: Total of 41 rubella cases identified. Index case and source of outbreak were not identified. Rubella sample positivity rate was 20%. First case seen on 5th January and last case on 19th February/2018. Most 23 (56.1%) cases were females and 17 (41.46%) among grade 1 and 2 students. Median age of cases was 10 years (IQR=4). Overall attack rate in the school was 1.39% and case fatality rate zero. All cases were complaining rash and 80.49% had fever. Educational status of grade 5-6 and 7-8 had 0.13- and 0.12-time reduced risk of developing rubella disease than grade 1-2 at P-value less than 0.05, respectively. Conclusion: Although index case and source of infection not identified, the outbreak might be driven by contact and sharing transportation service. Late notification causes late investigation and control. Provision of health education at school and community increase people’s awareness on rubella that contribute to control the outbreak.