Risk Factors of Chikungunya Outbreak in Mareka District, Southern Ethiopia, 2019: Unmatched Case Control Study

Chikungunya is a Ribonucleic Acid (RNA) virus that belongs to the alpha virus genus of the Togaviridae family. Chikungunya is an emerging vector-borne disease of high public health significance in World Health Organization’s South-East Asia Region. Factors associated with Chikungunya were identified. Unmatched a 1:2 case control study was conducted from 26 June-17 July, 2019. We recruited participants from health facilities and the community by structured questionnaire. Multivariable logistic regression was conducted to control confounders and to identify factors associated with Chikungunya. Entomological investigation was conducted and forty households and ten containers were surveyed to determine house and breteau indices. Fourteen serum-samples were tested by reverse transcription polymerase chain reaction (RT-PCR). A total of 94 cases were reported. Females accounted for (59.6%) of the cases and (52.1%) of the controls. Presence of Chikungunya case in the house hold (Adjusted odds ratio=6.7; 95%CI (3.42-13.03); P=<0.001); Water holding container (AOR=2.85, 95%CI (1.37-5.91); P=0.005), presence of larva (AOR=2.85; 95%CI (1.27-6.40); P=0.011) and Short and Long sleeves (AOR=2.2; 95%CI (1.144-4.267); P=0.018) were the independent risk factors. House and breteau indices were 100% and 20% respectively. Eight out of fourteen samples tested were positive. The presence of Chikungunya case in the household, water holding container in or around the house, larva around the villages in favorable mosquito breeding sites and in the containers and not using long sleeve clothes were risk factors for contracting the diseases.