Sero-epidemiological survey of Crimean-Congo hemorrhagic fever virus in Tunisia.

Fares Wasfi,Stuart Dowall,Roger Hewson,Tayssir Ghabbari,Mohamed Chakroun,Anitha Varghese,Abir Znazen,Elyes Zhioua,Amel Letaief,Mounir Ben Jemaa,Andrew Bosworth,Hanene Tiouiri

doi:10.1051/parasite/2016010

Abstract

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne disease associated with a high case fatality rate and transmitted mainly by Hyalomma marginatum. The geographical distribution of H. marginatum covers most of the Western Mediterranean basin. We aimed to investigate whether CCHF virus (CCHFv) is circulating in Tunisia. Samples from unexplained acute febrile patients (n = 181) and a high risk group of humans, mainly slaughter workers (n = 38), were collected in the summer of 2014 and analyzed for exposure to CCHFv using serological tests and real-time RT-PCR. Ticks were collected from Northern and Southern Tunisia during May–June 2014 and examined for the presence of CCHFv by real-time RT-PCR. Of the 181 febrile patients, 5 showed only high titers of IgM suggesting a recent exposure to CCHFv. Among 38 slaughter workers, 2 had IgG anti-CCHFv responses yielding a seroprevalence of 5.2%. No CCHFv was detected in ticks and sera. Our results provide evidence of human exposure to CCHFv in Tunisia.

Highlights

While CCHF virus (CCHFv) is mainly transmitted through tick bites, humans may become infected through direct contact with the blood or tissues of infected humans or livestock [14, 19, 21, 22]
None of the patients had traveled to known overseas endemic areas for Crimean-Congo hemorrhagic fever (CCHF) nor reported a history of tick bites
No positive cases of CCHFv were detected by RT-PCR analysis

Summary

Introduction

CCHFv is maintained in nature through a transmission cycle involving ticks and vertebrate hosts and is transmitted mainly through the bite of ixodid ticks [7, 9, 12, 26, 30]. H. marginatum is a two-host tick with larvae and nymphs feeding mainly on small mammals and birds while adults feed on large mammals including livestock [12]. Migratory birds play a significant role in spreading CCHFv between Africa and Europe [15, 17, 24]. While CCHFv is mainly transmitted through tick bites, humans may become infected through direct contact with the blood or tissues of infected humans or livestock [14, 19, 21, 22]. Farmers and butchers are at high risk for CCHFv infection [21, 22]

Objectives

Methods

Results

Conclusion