First Serological Evidence of Crimean-Congo Hemorrhagic Fever Virus and Rift Valley Fever Virus in Ruminants in Tunisia.

Khaoula Zouaghi,Aymen Mamlouk,Rebecca Surtees,Ali Bouattour,Eva Krause,Hajer Aounallah,Andreas Nitsche,Janine Michel,Youmna M’Ghirbi

doi:10.3390/pathogens10060769

Abstract

Crimean-Congo hemorrhagic fever virus (CCHFV, Nairoviridae family) and Rift Valley fever virus (RVFV, Phenuiviridae family) are zoonotic vector-borne pathogens with clinical relevance worldwide. Our study aimed to determine seroprevalences of these viruses and potential risk factors among livestock (cattle, sheep, and goats) in Tunisia. Sera were tested for antibodies against CCHFV (n = 879) and RVFV (n = 699) using various enzyme-linked immunosorbent assays (ELISAs) and indirect immunofluorescence assays (IIFA). The overall seroprevalence of IgG antibodies was 8.6% (76/879) and 2.3% (16/699) against CCHFV and RVFV, respectively. For CCHF seropositivity bioclimatic zones and breed were potential risk factors for the three tested animal species; while the season was associated with cattle and sheep seropositivity, tick infestation was associated with cattle and goats seropositivity and age as a risk factor was only associated with cattle seropositivity. Age and season were significantly associated with RVFV seropositivity in sheep. Our results confirm the circulation of CCHFV and RVFV in Tunisia and identified the principal risk factors in ruminants. This knowledge could help to mitigate the risk of ruminant infections and subsequently also human infections.

Highlights

Serum samples collected from cattle, sheep and goats in various bioclimatic zones across North and Central Tunisia were tested by enzyme-linked immunosorbent assays (ELISAs) for antibodies targeting CCHFV (n = 879)
The results of the indirect immunofluorescence assays (IIFA) were considered the final results for the presence or the absence of CCHFV or RVFV specific IgG antibodies
The serological screening of animals revealed for the first time in Tunisia, the presence of anti-CCHFV and anti-RVFV antibodies in cattle, sheep, and goats, with an overall seroprevalence of 8.6% (76/879) and 2.3% (16/699), respectively

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Crimean-Congo hemorrhagic fever virus (CCHFV, Nairoviridae family) and Rift Valley. Fever virus (RVFV, Phenuiviridae family) are the causative agents of Crimean-Congo hemorrhagic fever (CCHF) and Rift Valley fever (RVF), respectively. These viruses belonging to the Bunyavirales order have clinical relevance worldwide [1]. CCHFV of the Orthonavirus genus is transmitted to large and small mammals and birds(with the exception of ostriches), by ticks [2]. Humans are infected by tick bites, or through exposure to blood or infected tissues from viremic animals, or infected persons [3]

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