Crimean-Congo hemorrhagic fever (CCHF) is an endemic viral disease in Pakistan. Livestock handlers and butchers are a high-risk population. The study objective was to explore the risk factors associated with CCHF. Case-control study (age- and sex-matched), from 2016 to 2020, in Sindh-Pakistan. Cases were confirmed with laboratory evidence of CCHF viral RNA. Controls had no acute febrile illness. Standardized questionnaires collected demographic, clinical, laboratory, and risk factor data. Multivariate logistic regression was used to calculate adjusted odds ratios (aOR; 95%CI; p<0.05). There were 81 cases and 324 controls. Overall attack rate was 2.3 per million. Peak number of CCHF cases occurred between July and October (around the Islamic festival Eid-al-Adha) each year. Being a butcher (OR=2.0; 95%CI 1.1-4.0), visiting the cattle market (OR=102; 95%CI 13-765), having contact with a confirmed case (OR=280; 95%CI 20-3762), and having a history of a tick bite (OR=560; 95%CI 29-10642) were associated with CCHF infection. Identified CCHF risk factors included butcher, history of tick bite, contact with confirmed cases, and visiting cattle markets. Most cases occurred during Eid-Al-Adha, holiday known for increased livestock activity and animal trading. Correct use of acaricides and personal protective equipment among high-risk groups is recommended.

Keywords: Crimean-Congo hemorrhagic fever, case-control study, butcher, livestock handlers, Sindh, Pakistan