# Ticks and Associated Rickettsiae from Domestic Animals in Bhutan

## TL;DR

This study identifies various tick species and associated rickettsiae in domestic animals in Bhutan, highlighting the need for further research on tick-borne diseases.

## Contribution

The study provides the first documentation of tick species and rickettsiae in Bhutan, contributing to understanding regional tick-borne disease risks.

## Key findings

- Twelve tick species were identified, with Rhipicephalus microplus being the most common.
- Rickettsiae sequences aligned with multiple known species, though phylogenetic analysis had low confidence.
- The study emphasizes the need for larger studies to assess tick-borne disease impacts on livestock and human health.

## Abstract

In Bhutan, information on rickettsiae is limited to a few epidemiological studies. There is no information on ticks and tick-associated rickettsiae. Ticks were collected opportunistically from domestic animals residing in eight districts where a seroprevalence study had been carried out previously. Morphological identification of the ticks was performed in the United States National Tick Collection and testing for rickettsiae was carried out in the Australian Rickettsial Reference Laboratory. Samples positive for rickettsiae by qPCR were subjected to conventional PCR followed by DNA sequencing and phylogenetic analysis. A total of 200 ticks were sampled from 155 domestic animals including cattle, dogs, goats, horses, yaks, sheep and cats. The ticks belonged to twelve different species, the commonest being Rhipicephalus microplus, followed by Rhipicephalus haemaphysaloides, Haemaphysalis sp. near ramachandrai, Haemaphysalis tibetensis, Haemaphysalis bispinosa, Haemaphysalis sp., Haemaphysalis sp. near davisi, Rhipicephalus sanguineus, Haemaphysalis shimoga, Haemaphysalis hystricis, Ixodes ovatus, and Amblyomma testudinarium. Rickettsial DNA sequence analysis showed that the rickettsiae infesting ticks in Bhutanese domestic animals aligned with R. gravesii, R. canadensis, R. honei, R. africae, R. felis, R. akari, R. australis, R. japonica, R. africae, R. heilongjiangensis, R. conorii, R. peacockii, R. honei, R. massiliae and R. rhipicephali. However, these may not be conclusive due to low bootstrap values in the phylogenetic tree. Bhutan will benefit from larger studies on ticks and tick-borne infections, burden and damage assessment to livestock and human health, public health interventions and clinical guidelines to reduce morbidity and mortality in human and animal health.