Seasonal patterns of Crimean–Congo hemorrhagic fever in Afghanistan: environmental factors and public health implications, 2022–2024

Crimean-Congo hemorrhagic fever (CCHF) is endemic in Afghanistan and is associated with high case-fatality rates. This study aimed to describe the epidemiological, seasonal, and clinical characteristics of suspected and PCR-confirmed CCHF cases. A retrospective observational study was performed involving patients with suspected CCHF admitted to Kabul National and Specialized Infectious Diseases Hospital (Shafa Khane Antani) from January 2022 to December 2024. All patients were tested using real time PCR. Patients were classified as suspected, probable, or confirmed cases according to WHO case definitions. Seasonal and occupational trends, symptom patterns, and case-fatality rates (CFR) were analyzed. Totally, 45.3% of 880 patients with suspected infection were positive. The median age was 30 years, and majority of patients were male. Veterinarians represented the highest-risk occupational group. The incidence of CCHF showed marked seasonality, highest in May. Fever, bleeding, and diarrhea were significantly correlated with positive results. The CFR among PCR-confirmed cases with known outcomes was 15.4%. CCHF in Afghanistan exhibits distinct seasonal and occupational patterns. PCR-based surveillance identified symptomatic profiles associated with viremic infection. These findings support targeted occupational safety measures, continuous surveillance, and public health interventions timed to seasonal peaks, complementing serology-based studies of convalescent infections.