Prevalence of Ticks Infesting Dairy Cattle and the Pathogens They Harbour in Smallholder Farms in Peri-Urban Areas of Nairobi, Kenya

Abstract

This study aimed at determining the tick species infesting dairy cattle in Nairobi, Kenya, and the pathogens they harbour. While ticks are well-known vectors of major bacterial pathogens of both veterinary importance and public health importance, few studies have investigated the range of the tick species and the associated pathogens, especially present in unique dairy production systems, which compromise animal welfare, such as those in peri-urban areas. A cross-sectional study was undertaken involving 314 randomly selected dairy cattle in 109 smallholder farms. Each animal was examined for attached ticks followed by morphological tick identification at the species level. Genomic DNA was extracted from each of the ticks, and 16S rDNA gene was amplified for pathogen identification. Sequencing of the amplicons and subsequent BLASTn analysis, multiple sequence alignment, and phylogenetic reconstruction were performed to confirm the species of the pathogens. Sixty-six (21.0%) of the cattle examined had ticks. A total of 94 adult ticks were found on the cattle, and of these, 63 (67.0%), 18 (19.1%), and 13 (13.8%) were in the genera Rhipicephalus, Amblyomma, and Hyalomma, respectively. Twelve tick species in Rhipicephalus genus and two in Amblyomma and Hyalomma genera were identified. Although Rh. decoloratus was the most prevalent tick (24.5% (23/94)), the emerging Rh. microplus (6.4% (6/94)) was also identified. The DNA of Rickettsia was detected in the ticks, with Rickettsia conorii in H. rufipes and A. variegatum, and Rickettsia aeschlimannii in Rh. microplus and H. rufipes, while Ehrlichia ruminantium and E. canis were in A. variegatum. In conclusion, the study reported a wide range of tick species present in the study area including Rhipicephalus microplus, which is an emerging tick species in parts of Kenya. The ticks harboured DNA of Rickettsia and Ehrlichia, highlighting possible animal and human health concerns. Hence, effective tick control strategies remain paramount to prevent potential diseases associated with the harboured pathogens.

Prevalence, trend comparisons, and identification of ixodid ticks (Acari: Ixodoidea) among cattle in Ethiopia: A systematic review and meta-analysis

“…Rhipicephalus ( Boophilus ) (47.53%) was the most abundant tick genus in Ethiopia. This finding is in agreement with the report of the study done by ( Peter et al, 2021 ) in Kenya, where Rhipicephalus was the most abundant genera with a prevalence of 67.0%. Hyalomma was the least abundant tick species in Ethiopia, with a prevalence of 6.37%.…”

“…Hyalomma was the least abundant tick species in Ethiopia, with a prevalence of 6.37%. This report coincides with the previous studies with a prevalence of 4.7% and 13.8% by ( Teshome et al, 2016 ) and ( Peter et al, 2021 ) in Oromia, Ethiopia, and Nairobi, Kenya, respectively. However, the current study disagrees with the study reported by ( Fesseha and Mathewos, 2020 ) in Hossana district, Hadiya zone, Ethiopia, which stated that Hyalomma was the most abundant tick genus with a prevalence of 11.9%.…”

Metagenomic Investigation of Ticks From Kenyan Wildlife Reveals Diverse Microbial Pathogens and New Country Pathogen Records

“…These trends facilitate interactions between livestock, humans, and wildlife in a complex environment, increasing the opportunity for pathogen spill-over events (Okal et al, 2020). Several tick-borne bacterial, viral, and parasitic agents have been documented in Kenya, including agents of anaplasmosis, ehrlichiosis, rickettsiosis, Crimean-Congo hemorrhagic fever (CCHF), babesiosis, and theileriosis (Omondi et al, 2017;Morrison et al, 2020;Okal et al, 2020;Chiuya et al, 2021;Getange et al, 2021;Peter et al, 2021), with occasional reporting of novel pathogens (Mwamuye et al, 2017). However, reports from wildlife are relatively rare and often focus on well-documented bacterial agents.…”

Prevalence of Tick Infestations and Tick-Borne Diseases in Cattle in Cameroon

“…These include [39] [48] [49]. However, other authors have given prevalence ranging from 1.8% to 13.8% [45] [50] [51].…”