Crimean-Congo Hemorrhagic Fever Virus Circulation in Wild European Rabbits, Portugal, 2018-2023.

Area of Science:

• Veterinary Virology
• Public Health Entomology
• Zoonotic Disease Surveillance

Background:

• Crimean-Congo hemorrhagic fever virus (CCHFV) is a significant public health concern in southwestern Europe.
• European rabbits (Oryctolagus cuniculus) are known hosts for immature Hyalomma lusitanicum ticks, potential vectors for CCHFV.
• Understanding CCHFV prevalence in wildlife reservoirs is crucial for assessing transmission risk.

Purpose of the Study:

• To investigate the seroprevalence of CCHFV antibodies in European rabbit populations in Portugal.
• To identify potential geographical hotspots of CCHFV infection within the study area.
• To evaluate the role of European rabbits as hosts in the CCHFV transmission cycle.

Main Methods:

• Serum samples were collected from 667 European rabbits across Portugal.
• Antibodies against CCHFV were detected using serological assays.
• Geographical distribution of positive cases was analyzed to identify clusters.

Main Results:

• Overall low seroprevalence of CCHFV antibodies was detected, with less than 1% of rabbits testing positive.
• A localized cluster of infection was identified in southern Portugal, with a seroprevalence of 5.77% in that specific region.
• The findings suggest a limited but present CCHFV circulation within European rabbit populations.

Conclusions:

• European rabbits in Portugal exhibit low but detectable levels of CCHFV antibodies.
• Southern Portugal shows a localized higher prevalence, highlighting potential CCHFV endemic areas.
• Further research is needed to fully elucidate the role of rabbits and ticks in CCHFV epidemiology in Europe.