Investigation of Crimean-Congo Hemorrhagic Fever Virus (CCHFV) in Hyalomma spp. ticks and evaluation of knowledge and practices related to ticks and CCHF among the Karamojong pastoralists in Moroto district, Uganda

Sammanfattning: Crimean-Congo Hemorrhagic Fever (CCHF) is a fatal disease in humans and one of the most wide spread viral tick-borne diseases (TBD) with cases found in Africa, Asia and Europe. Ticks are the main vectors of the causative agent CCHFV, Crimean-Congo Hemorrhagic Fever Virus. CCHF presents with symptoms like fever, weakness, headache, and hemorrhagic signs (e.g. hematemesis and epistaxis). There are different tick species able to transmit the virus, where species within the genus Hyalomma spp. are the most common. In Uganda, ten human cases of CCHF have been confirmed since 2013, and the global awareness about the disease in increasing. In a non-published study by Balinandi et al. from 2017, antibodies towards CCHFV was found in serum samples from cattle in the Moroto district in North-Eastern Uganda, in 2017, where previously no human cases of CCHF have been documented. The aim for this study, was therefore to investigate the prevalence of CCHFV in Hyalomma spp. in this region. A secondary aim was to get a better understanding of what the local cattle owners know about ticks, TBDs and prevention in both animals and humans. This was done by interviews using a structured questionnaire. In total, 504 Hyalomma spp. (n=485 Hyalomma truncatum, n=19 Hyalomma rufipes), were collected from cattle in two different sub-counties (Nadunget and Rupa) in Moroto district. In total 474 Hyalomma spp. were divided in pools of five or less, total nucleic acid was extracted and tested by qRT-PCR in search for viral RNA of the CCHFV. All tick samples analyzed were negative of CCHFV. This result does not necessarily mean that the virus does not exist in the region, but rather could suggest that other tick species can be responsible for transmitting the virus. Another explanation could be that the prevalence of CCHFV is very low and not enough Hyalomma spp. were tested. Description of two possible human cases of CCHF were reported during the interviews which strengthens the suspicion of CCHFV being present and causing disease in humans also in this region. During these interviews it got clear that the cattle herd owners want more help from the government to handle TBDs. It was prominent too that there is an apparent lack of knowledge of the potential severity of TBDs in humans and how to prevent them. Education programs and other prevention measures should be implemented for future improvements for the health care of both animals and humans.