Determinants of crimean-congo hemorrhagic fever (cchf) outbreaks: a retrospective analysis

Abstract Introduction Crimean-Congo Hemorrhagic Fever (CCHF), a viral tick-borne zoonotic disease with high mortality rates, poses a particular threat in Pakistan during religious event of Eid-ul-Azha as increased livestock contact. This study aims to analyze CCHF cases from three outbreaks, to identify transmission and disease patterns. Understanding these patterns can inform targeted interventions for future outbreaks. Methods A retrospective cross-sectional study was conducted to examine three CCHF outbreak investigations between July 2nd and August 12th, 2023 in Khyber Pakhtunkhwa, Pakistan. Multisectoral teams, including human and animal health departments, investigated these outbreaks. Data was collected through semi-structured case investigation tools. The healthcare providers, patients and family were subjects. During active case surveillance, 41 probable contacts were traced. Results Among positive cases, male predominance (71.4%) was observed. The highest proportion of cases occurred in the 15-29 year age group (42.9%, n = 6). Individuals involved in animal handling professions had the highest prevalence (50%, n = 7), followed by students (21.4%, n = 3). Common clinical manifestations included high-grade fever (100%), muscle pain (92.9%), and bleeding symptoms (85.7%), with 64.3% of cases reporting vomiting blood. The average recovery time was 7.1 days, while fatal cases had an average of 6.8 days from symptom onset to death. Recovery was observed in 64.3% of cases, with a mortality rate of 35.7%. Chi-square analysis showed significant associations between gender, occupation, and disease outcome (p < 0.05). Conclusions This study identified a higher risk of CCHF in males, young adults, and individuals involved in animal handling during outbreaks. Public health interventions targeting occupations, demographics, particularly education and protective measures for animal handlers during Eid-ul-Azha days, are crucial to mitigate future outbreaks Key messages • Young male adults, and individuals involved in animal handling are on greater risk of higher risk of CCHF infections in Khyber Pakhtunkhwa, Pakistan. • One Health community can leverage these findings to develop better prevention and control strategies through collaboration between human and animal health sectors.