Characterizing tick diversity among caprine hosts of Kerala, India: a phylogenetic study

Ticks are prominent vectors of numerous pathogens that adversely affect human and animal health. Monitoring tick population dynamics is key in developing ideal tick-borne disease surveillance systems and critical vector control programmes. This study aimed to conduct the morphological and molecular characterization of ticks infesting domesticated goats in Kerala, India.

A total of 30 goats presented to the small ruminant unit of the Teaching Veterinary Clinical Complex (TVCC), Mannuthy were randomly screened for tick infestation, with 22 (73.3%) found to be infested. Morphological identification of different life cycle stages and genera was conducted first, utilizing documented external characteristics such as body size, presence of eyes, and other key morphological traits. A total of 153 tick samples were collected from goats, and their identification revealed that they belonged to the genera Haemaphysalis and Rhipicephalus. This was followed by molecular analysis through sequencing a fragment of the cytochrome c oxidase subunit I (COXI) gene, a standard marker for tick identification. The results from molecular and phylogenetic analyses confirmed the tick species as Haemaphysalis bispinosa, H. intermedia, Rhipicephalus haemaphysaloides, and R. sanguineus. The sequenced specimens were deposited in the NCBI GenBank contributing to the global understanding of tick distribution and diversity in goats. The GenBank accession no. (s) of the isolates are PQ433166 (H. bispinosa), PQ433290 (H. intermedia), PQ433525 (R. haemaphysaloides), and PQ433586 (R. sanguineus).

The findings of this study contribute to a better understanding of the tick fauna infesting goats in the region and emphasize the importance of developing research and monitoring plans to address the challenges posed by these ectoparasites. It also highlights a critical area for future study, targeting the vector potential of these arthropods in hemoparasitic diseases and zoonotic disease transmission.