Crimean Congo hemorrhagic fever virus exposure among febrile patients, cattle herders, and cattle herds in Cameroon

Acta Trop. 2024 Dec:260:107432. doi: 10.1016/j.actatropica.2024.107432. Epub 2024 Oct 18.

Abstract

Problem addressed: Crimean Congo hemorrhagic fever (CCHF) is a tick-borne disease with high fatality rates and an expansive geographic distribution, yet disease prevalence data in Cameroon is lacking.

Objective: This study aimed to determine CCHF virus (CCHFV) seroprevalence and tick distribution among cattle herders and febrile patients in West and Centre Cameroon.

Methods and approach: Two cross-sectional serological studies of human and cattle were conducted from October to December 2021 and from June to July 2022, which included the collection of ticks. Enzyme-linked immunosorbent assay (ELISA) were used to detect anti-CCHFV antibodies, while a knowledge, attitudes, and practice (KAP) survey assessed tick and tickborne disease related knowledge and behaviors among herders. Tick identification used morphological keys.

Results: The KAP survey showed adequate tick knowledge (94.5 %) among herders but poor understanding of disease transmission, with favorable attitudes towards tick control (24.7 %) but inadequate implementation. Rhipicephalus annulatus (64.1 %) predominated among the 1,296 ticks collected during each rainy season. Among cattle, 27.4 % were seropositive, and seropositivity was associated with specific villages, cattle age (>4 years), and female sex. Herders had a 17.8 % seroprevalence, while febrile patients had 8.3 %, with higher rates in those >20 years old for both groups. Self-reported tick removal by herders after contact and grazing may increase CCHFV exposure.

Conclusions: This study confirms CCHFV circulation in rural West Cameroon and unexpected exposure risk in Yaounde, highlighting the need for active entomological surveillance and preventive measures in transhumance and cattle market activities. Establishing an occupation-based surveillance system can help identify CCHFV hotspots to prevent outbreaks.

Keywords: Antibodies; CCFHV; CCHF; Cameroon; Seroprevalence; Ticks.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Animals
  • Antibodies, Viral / blood
  • Cameroon / epidemiology
  • Cattle
  • Cattle Diseases* / epidemiology
  • Cattle Diseases* / virology
  • Child
  • Cross-Sectional Studies
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Fever / epidemiology
  • Fever / virology
  • Health Knowledge, Attitudes, Practice*
  • Hemorrhagic Fever Virus, Crimean-Congo* / immunology
  • Hemorrhagic Fever Virus, Crimean-Congo* / isolation & purification
  • Hemorrhagic Fever, Crimean* / epidemiology
  • Hemorrhagic Fever, Crimean* / transmission
  • Hemorrhagic Fever, Crimean* / veterinary
  • Hemorrhagic Fever, Crimean* / virology
  • Humans
  • Male
  • Middle Aged
  • Seroepidemiologic Studies
  • Ticks / virology
  • Young Adult

Substances

  • Antibodies, Viral