Risk factors for Crimean-Congo Haemorrhagic Fever (CCHF) virus exposure in farming communities in Uganda

J Infect. 2022 Dec;85(6):693-701. doi: 10.1016/j.jinf.2022.09.007. Epub 2022 Sep 13.

Abstract

Background: Crimean-Congo Haemorrhagic Fever (CCHF) is an emerging human-health threat causing sporadic outbreaks in livestock farming communities. However, the full extent and the risks associated with exposure of such communities has not previously been well-described.

Methods: We collected blood samples from 800 humans, 666 cattle, 549 goats and 32 dogs in districts within and outside Ugandan cattle corridor in a cross-sectional survey, and tested for CCHFV-specific IgG antibodies using Enzyme-Linked Immunosorbent Assays. Sociodemographic and epidemiological data were recorded using structured questionnaire. Ticks were collected to identify circulating nairoviruses by metagenomic sequencing.

Results: CCHFV seropositivity was in 221/800 (27·6%) in humans, 612/666 (91·8%) in cattle, 413/549 (75·2%) in goats and 18/32 (56·2%) in dogs. Human seropositivity was associated with livestock farming (AOR=5·68, p<0·0001), age (AOR=2·99, p=0·002) and collecting/eating engorged ticks (AOR=2·13, p=0·004). In animals, seropositivity was higher in cattle versus goats (AOR=2·58, p<0·0001), female sex (AOR=2·13, p=0·002) and heavy tick infestation (>50 ticks: AOR=3·52, p=0·004). CCHFV was identified in multiple tick pools of Rhipicephalus appendiculatus.

Interpretation: The very high CCHF seropositivity especially among livestock farmers and multiple regional risk factors associated exposures, including collecting/eating engorged ticks previously unrecognised, highlights need for further surveillance and sensitisation and control policies against the disease.

Keywords: CCHF; CCHF antibodies; CCHF risk factors; CCHF seroprevalence; Crimean-Congo Hemorrhagic fever virus; Uganda; Viral Haemorrhagic Fever; emerging and re-emerging infections; tick-borne arbovirus; tick-borne viral infections; zoonotic disease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Agriculture
  • Animals
  • Cattle
  • Cross-Sectional Studies
  • Dogs
  • Female
  • Goats
  • Hemorrhagic Fever Virus, Crimean-Congo*
  • Hemorrhagic Fever, Crimean* / epidemiology
  • Humans
  • Risk Factors
  • Ticks*
  • Uganda / epidemiology