Fourth Dengue Fever Outbreak Investigation in Ethiopia: A Case Control Study, July 2015

Abstract Background: Dengue fever is a rapidly emerging vector born infectious disease caused by Dengue virus and it is now one of WHO reportable diseases. About 50 -200 million cases, 20,000 deaths occur annually. In Ethiopia the first outbreak of Dengue fever appeared in Dire Dawa city in 2013, where 9441 cases were recorded. The second Dengue fever outbreak occurred in Afar Region. Third and fourth was in Somali Region in Godey town, 2014 and 2015. In Godey town acute febrile illness cases of unknown cause become increased started from May 27, 2015. We investigated to identify risk factors of Dengue fever outbreak and commence control measures. Methods: A case-control study was conducted in Godey town, Ethiopia from 8-22 July 2015. Cases were defined according to the WHO guideline and controls were individuals with no sign and symptoms living in the same town with cases. We recruited 50 cases and 100 controls in the study. Medical records and line lists were reviewed. Data were collected at household level using structured questionnaires. Twenty-four serum samples collected from cases. Data was analyzed using SPSS 20 software. Result: We identified 223 cases with 0 death, 116 (52%) were male. The mean age of cases was 25.8 years. Ten cases were positive for Dengue fever by PCR at national laboratory. Lack of formal education (AOR=3.1; 95%CI: 1.30-7.49), living with ill person (AOR=2.8; 95%CI: 1.22-6.52), open containers in household (AOR=3.6; 95%CI: 1.34-9.38) and presence of larvae in the water containers (AOR=5.4; 95%CI: 2.33-12.44) were risk factors for the outbreak. Conclusion: Poor household water handling, living with ill person and lack of formal education contributes for occurrence of Dengue fever outbreak in Godey town. Health education and all other interventions associated with use of water and sanitation needs to be part of long-term control of Dengue.