A systematic review of ticks and tick-borne pathogens of cattle reared by smallholder farmers in South Africa

Ticks are important ectoparasites of domestic animals, wild animals and humans. They spread a variety of infective agents such as protozoans, viruses, and bacteria. Cattle reared by smallholder farmers are susceptible to ticks and tick-borne pathogens due to the type of production system practiced by the farmers. Hence, this review was focused on the occurrence of ticks and tick-borne pathogens in cattle reared by smallholder farmers in South Africa. The systematic search produced a total of 13,408 articles from four databases, and after screening processes, the review utilized 23 articles published between 1983 and 2023. A total of 26 tick species belonging to seven genera were identified in the reviewed articles, with Rhipicephalus (Boophilus) decoloratus and Rhipicephalus evertsi evertsi being the most frequently reported tick species in South Africa followed by Amblyomma hebreum, Rhipicephalus appendiculatus, Hyalomma marginatum rufipes, Rhipicephalus microplus, Rhipicephalus follis, Rhipicephalus gertrudae and Hyalomma truncatum. The most frequently reported tick-borne pathogens across the provinces included Babesia bigemina, Babesia bovis, and Anaplasma marginale, with Eastern Cape Province accounting for most of the records followed by KwaZulu-Natal and Mpumalanga Provinces. The findings of this review confirm that cattle reared by smallholder farmers harbour various ticks and tick-borne pathogens of veterinary, public health and economic importance, and regular monitoring of tick infestations in South Africa is recommended to avoid disease outbreaks.