Molecular identification of cattle ticks in the Greater Accra Region of Ghana: a high occurrence of Rhipicephalus microplus.

Ticks are competent vectors of a wide range of pathogens. They are of veterinary and public health importance as they affect both animal and human health. Transhumance and the transboundary movements of cattle within the West African Sub-region have facilitated the spread of ticks which threatens the introduction of invasive species. Currently, Rhipicephalus microplus have been identified in the Upper East Region of Ghana which could mean a wider distribution of the species across the country due to livestock trade. This study focused on three sites in the Greater Accra Region, which serves as the gateway to receiving most of the cattle transported from the northern regions of Ghana. Ticks were sampled from August 2022 in the wet season to January 2023 in the dry season. Three tick genera were identified: Amblyomma (19.5%), Hyalomma (1.1%), and Rhipicephalus (79.3%) from the 1,489 feeding ticks collected from cattle. Furthermore, Rhipicephalus microplus, Hyalomma rufipes and Amblyomma variegatum were identified molecularly using primers that target the mitochondrial COI gene. There was a significant association between the tick species and seasons (p < 0.001). Finding R. microplus in this study indicates the extent of the spread of this invasive tick species in Ghana and highlights the need for efficient surveillance systems and control measures within the country.

Tick-borne pathogens of zoonotic and veterinary importance in cattle ticks in Ghana.

Ticks are important vectors involved in the transmission of pathogens of zoonotic and veterinary importance. In this study, ticks were collected from cattle in Navrongo, Kintampo, and Kumasi and screened for pathogen DNA using PCR and Sanger sequencing. A total of 454 ticks were collected, morphologically identified and confirmed using primers that target the 660-bp segment of the mitochondrial COI gene. The predominant tick species was Amblyomma variegatum (70.26%). DNA was extracted from 85 tick pools and screened for the presence of Rickettsia DNA based on the 639 bp of the outer membrane protein A (ompA) gene, Ehrlichia/Anaplasma DNA based on the 345 bp fragment of the 16SrRNA gene and Babesia/ Theileria DNA based on the 560 bp fragment of the ssrRNA gene. From the 85 tick pools, the DNA of pathogens detected were Rickettsia africae (36.47%), Rickettsia aeschlimannii (16.47%), Ehrlichia canis (2.35%), Babesia occultans (1.18%), Theileria velifera (1.18%) and a symbiont Candidatus Midichloria mitochondrii (8.24%). This study reports the first molecular detection of Candidatus Cryptoplasma californiense (1.18%) in Ghana. Coinfections were recorded in 8.24% of the tick pools. The findings of this study highlight the importance of tick species in Ghana and the need to adopt effective control measures to prevent pathogen spread.