Seroprevalence of Crimean‐Congo haemorrhagic fever among three selected risk human groups in disease‐endemic region of Pakistan

Abstract

The occurrence of Crimean-Congo haemorrhagic fever (CCHF) in humans is linked with animals living in close vicinity, and information on the incidence of CCHF at the human-animal interface is scarce. Therefore, the current study was designed to identify the high-risk groups of individuals linked with animals in the Chakwal district of Pakistan having a history of CCHF cases in humans. In subject matter, coupled with risk factor analysis, we performed a sero-based CCHF surveillance in three selected risk groups of humans including abattoir workers (n=137), milkmen (n=169) and animal handlers (n=147). Sera samples and questionnaire-based data were collected from each of the participants and screened for anti-CCHFV IgG antibodies using enzyme-linked immunosorbent assay. The highest seroprevalence was observed in animal handlers (n=14, 9.52%, 95% CI: 4.68-13.99) followed by abattoir workers (n=9, 6.57%, 95% CI: 2.42-10.72) and milkmen (n=3, 1.78%, 95% CI: 0.24-4.24). The risk of seropositivity was significantly associated with humans linked with tick-infested animals (OR: 11.0, 95% CI: 1.5-83.0, p=.002), old age >40years (OR: 6.6, 95% CI: 2.7-16.0, p<.0001), illiteracy (OR: 4.3, 95% CI: 1.5-13.0, p=.004) and humans without knowledge about CCHF (OR: 7.6, 95% CI: 1.8-33.0, p=.0009). The findings of the current study highlighted the seroprevalence of CCHF in high-risk groups of humans living in a disease-endemic area of Pakistan and highlight the need for well-integrated disease surveillance in the future to better comprehend disease control interventions.