Serologic and molecular evidence for circulation of Crimean-Congo hemorrhagic fever virus in ticks and cattle in Zambia

Abstract

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne zoonosis with a high case fatality rate in humans. Although the disease is widely found in Africa, Europe, and Asia, the distribution and genetic diversity of CCHF virus (CCHFV) are poorly understood in African countries. To assess the risks of CCHF in Zambia, where CCHF has never been reported, epidemiologic studies in cattle and ticks were conducted. Through an indirect immunofluorescence assay, CCHFV nucleoprotein-specific serum IgG was detected in 8.4% (88/1,047) of cattle. Among 290 Hyalomma ticks, the principal vector of CCHFV, the viral genome was detected in 11 ticks. Phylogenetic analyses of the CCHFV S and M genome segments revealed that one of the detected viruses was a genetic reassortant between African and Asian strains. This study provides compelling evidence for the presence of CCHFV in Zambia and its transmission to vertebrate hosts.

Seroepidemiology of Crimean-Congo Hemorrhagic Fever Virus (CCHFV) in Cattle across Three Livestock Pastoral Regions in Kenya

“…The study findings reveal CCHFV exposure in cattle residing in the two major ecosystems including the Ol Pejeta Conservancy and Maasai Mara. The proportion was signifi-cantly greater compared to a study conducted in cattle in neighboring Uganda [34] and Zambia [9]. Interestingly, cattle in the Ol Pejeta Conservancy had a lower seroprevalence compared to those in Maasai Mara, and this may be attributed to livestock husbandry practices (see Table 1).…”

“…CCHFV is known to circulate in nature through an enzootic tick-vertebrate-tick cycle [6], with the natural vector being the tick Hyalomma spp [7] although other tick genera have also been shown to transmit CCHFV [6,8]. However, information on the distribution and genetic diversity of CCHFV is quite limited [9].…”

Current knowledge of vector-borne zoonotic pathogens in Zambia: A clarion call to scaling-up “One Health” research in the wake of emerging and re-emerging infectious diseases

“…Recently, compelling evidence of circulation of CCHFV in cattle and ticks in Zambia was provided [47], supporting the idea that CCHFV is endemic in most Southern African countries and is the most recognised tick-borne viral zoonoses globally [46]. In fact, most neighbouring countries of Zambia are endemic to CCHFV [46].…”

“…Infections due to CCHFV in humans are characterised by headache, fever, joint pain, stomach pain, and vomiting [46]. Currently, there is only a single report of CCHFV in Zambia, with IgG antibodies being detected in 8.4% (88/1,047) of cattle [47]. The pathogen genome was detected in 3.8% (11/290) of Hyalomma ticks, the principal vector of CCHFV [47].…”

“…Currently, there is only a single report of CCHFV in Zambia, with IgG antibodies being detected in 8.4% (88/1,047) of cattle [47]. The pathogen genome was detected in 3.8% (11/290) of Hyalomma ticks, the principal vector of CCHFV [47]. Genomic analyses revealed that one of the detected viruses was a genetic reassortant between African and Asian strains, intimating possible dissemination of CCHFV across continents.…”