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

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 center dot 6%) in humans, 612/666 (91 center dot 8%) in cattle, 413/549 (75 center dot 2%) in goats and 18/32 (56 center dot 2%) in dogs. Human seropositivity was associated with livestock farming (AOR= 5 center dot 68, p<0 center dot 0001), age (AOR=2 center dot 99, p=0 center dot 002) and collecting/eating engorged ticks (AOR=2 center dot 13, p= 0 center dot 004). In animals, seropositivity was higher in cattle versus goats (AOR= 2 center dot 58, p<0 center dot 0001), female sex (AOR=2 center dot 13, p=0 center dot 002) and heavy tick infestation (>50 ticks: AOR=3 center dot 52, p=0 center dot 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. (c) 2022 The Authors. Published by Elsevier Ltd on behalf of The British Infection Association. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Automated summary

The study reveals a high prevalence of Crimean-Congo Haemorrhagic Fever (CCHF) in livestock farming communities in Uganda, with factors such as livestock farming, age, and collecting/eating engorged ticks associated with human seropositivity. This emphasizes the importance of further surveillance and control measures against the disease.