Lead


Lay summary
Ticks represent a challenge to the South African livestock industry and to game ranging and conservation initiatives mainly due to tick-borne pathogens. In South Africa, where animals and their products correspond to 48% of the agriculture production, tick-borne diseases represent considerable economic losses. The problem related to ticks is also a challenge for game ranging on game farms since this sector also became important with the increase of ecotourism. In South Africa, many farmers breed wild animals with cattle and small ruminants in order to increase their income through game viewing and hunting. In addition, game translocations, which are increasing through international conservation efforts, constitute a high risk of spreading ticks and their pathogens. Wild animals may be the origin of livestock infections by tick-borne pathogens and vice-versa. However, the role and importance of wild and domestic animals in the circulation of these pathogens are fairly unknown. Here, we intend to investigate wild and domestic animals for ticks and tick-borne pathogens. One of our aims is to clarify the situation in wildlife and domestic animals by studying the host and vector ranges of these pathogens as well as their geographic distribution. This information is essential to optimize cattle and wildlife management strategies. The second aim targets two tick and Babesia species that are currently competing in the studied area. We will compare the population genetic features of an invasive tick, Rhipicephalus microplus, and an out-competed tick, R. decoloratus and precise the outputs of their competition relative to the Babesia threats. R. microplus was introduced to Africa from Asia and is the unique vector of the very virulent Babesia bovis as well as a potential vector of the less virulent B. bigemina. Along its invasion, R. microplus is displacing the native tick R. decoloratus, a vector of B. bigemina but not of B. bovis. Combining a survey of these two Babesia among wild and domestic ruminants, and in ticks, is a prerequisite to forecast the emergence of B. bovis, and to apply protection measures. We will collect ticks and tissue samples from wild and domestic animals where they have contacts with each other and analyse them using molecular tools. To monitor the displacement of R. microplus and of B. bovis into new areas, we will investigate the borders between areas where R. microplus is known to occur and areas where this tick species has not yet been described. The population genetic analyses of both tick species will be performed.