Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

United States Department of Agriculture (USDA) National Institute of Food and Agriculture

Titre : ASSESSMENT OF CCHV IN UGANDAN CATTLE CORRIDOR AND KENYAN ARID NORTH TICK POPULATIONS

Identification : 0442808

Pays : Etats Unis

Durée : START : 01 SEP 2022 TERM : 30 APR 2027

Objectifs
The emphasis of the agreement will be on examining Hyalomma species of ticks for pathogens that affect animal and human health. The objectives of this agreement will be to identify tick species diversity of the Ugandan cattle corridor and the Kenyan arid north region, assess tick blood meal sources, delineate temporal and spatial Crimean-Congo Hemorrhagic fever virus (CCHFV) infection rates in tick populations, and characterize the tick virome. CCHFV is an enveloped, negative-sense RNA virus, vectored principally by Hyalomma species of ticks. CCHFV causes a contagious zoonosis resulting in haemorrhagic fever with a case fatality rate between 3% and 80%. CCHFV also possesses a high degree of genetic diversity with a potential of new and highly-pathogenic variants emerging, which can impact pastoralists in contact with animals infested with Hyalomma ticks. Despite the occurrence of multiple outbreaks in East Africa since 2013, CCHFV remains poorly characterized with paucity of knowledge of its epidemiology, population burden, and viral characteristics. The data obtained in this study will establish the prevalence of CCHFV and other tick-borne pathogens, as well as the intra- and interpopulation genetic variability of CCHFV isolated from ticks collected in different seasons and ecological zones, and will identify any novel pathogens transmitted by ticks along the Kenya-Ugandan border. These studies will also help prepare the United States agriculture and public health systems for the potential introduction of CCHFV or other tick-borne emerging pathogens by gaining a greater understanding of the epidemiology of CCHFV transmission in East Africa. Collaborators will collect ticks from livestock, camels, goats and sheep in the homesteads, market, and abattoirs during the wet and dry seasons found in the Ugandan cattle corridor and the Kenyan arid north regions. Taxonomic keys and genetic tools will be used for identification of ticks. Transmission dynamic risks of CCHFV will be assessed by identifying the blood meal sources of each tick species while spill over risks will be determined by comparing the temporal and spatial infection rates associated with different tick species. Further, to identify other viruses transmitted by ticks collected from these regions, collaborators will utilize deep sequencing to characterize the tick virome of a few pools of ticks representing the different tick species collected from the Uganda and Kenya. Additionally, this will assess the variation of the tick virome across seasons. The results of this project will identify the incidence of CCHFV in tick populations and provide detailed information on the species of ticks infected by CCHFV, as well as the identification of novel viruses transmitted by ticks in these regions.

Performing Institution : TEXAS TECH UNIVERSITY
Investigator : COHNSTAEDT L W ; MIRE C E ; BRESLFOARD C ; MITZEL D N ; NORONHA L E ; ONYANGO M

Présentation : USDA (NIFA)