No abstract

The first study on ticks on reptiles of Sri Lanka dates back to Seneviratna (1965) who reported ticks from five reptiles. Later studies were either limited to one reptile (Fernando & Fernando 2012), or captive animals in zoos (Fernando & Randeniaya 2009) and household pets (Nathanael et al. 2004). According to the current classification (Guglielmone et al. 2010), all the tick species previously recorded on reptiles belong to five species of Amblyomma: A. clypeolatum Neumann, A. gervaisi (Lucas), A. pattoni (Neumann), A. trimaculatum (Lucas) and A. varanense (Supino). Some of the species listed by Seneviratna (1965) were either synonyms or invalid in respect to the present classification. For example Amblyomma laeve sensu Warburton (1910) is a junior synonym of A. pattoni and A. gervaisii var. lucasi is considered a junior synonym of A. varanense (Guglielmone et al. 2010; D. Apanaskevich pers. comm.).

Ticks are the most important ecto-parasites of livestock in tropical and subtropical areas, and are responsible for severe economic losses in livestock. Ticks are a major veterinary concern as they transmit pathogens, produce tick paralysis or toxicosis, and reduce production in livestock. The cost of worldwide economic losses and the additional burden of protecting livestock against ticks and tick-borne diseases are now estimated to be billions of dollars annually.The main objective of this study was to determine the tick diversity in farm animals from selected areas of Sri Lanka. Additionally, the possibility of the introduction of tick species from wildlife into livestock was also investigated. Ticks were collected from livestock in 30 locations in the Wet zone and 30 locations in the Dry zone (representing both rural and urban regions), covering most parts of Sri Lanka, during the years 2009 and 2010. Eighteen (18) tick species were recorded in the present study, indicating a fair increase in tick species reported in livestock in Sri Lanka. The findings included rare tick species, which has been previously reported only on wild animals. Some tick species showed a host preference while others have expanded their geographical and host range.

Spotted fever group rickettsial infections are considered an emerging infectious disease in Sri Lanka. The present study examined the potential role of tick vectors carrying the infection from sylvatic reservoirs to humans via domesticated animals. Ticks infesting humans, dogs and wild animals were collected island-wide and were identified. Presence of spotted fever group rickettsia in the tick blood meal was determined using PCR in a sub-sample of ticks collected. A total of 30,933 ticks were collected from 30 different hosts and free living stages from the ground. The collection consisted of 25 tick species recording 12 species from humans, 19 from domesticated animals and 22 from wild animals. Of the total collection, randomly selected sub-sample of 80 ticks were used to identify rickettsia pathogens. This comprised of fifty ticks from 50 wild animals belonged to 15 species (wild boar, pangolin, porcupine, barking deer, star tortoise, mouse deer, samber, spotted deer, monkey, civet cat, bandicoot, elephant, fishing cat, rabbit, flying squirrel; and 20 ticks from 15 dogs especially from areas where spotted fever cases were reported and 10 ticks from 10 humans. Results showed that rickettsial infections were found in four tick species, Amblyomma testudinarium collected from a wild boar, Riphicephalus sanguineus from a dog, Amblyomma clypeolatum from a star tortoise and Amblyomma javanense from a pangolin. Except for A. javanense, other three tick species are generalists infesting humans as well as domestic and wild animals. There is a high potential that these infections can spread easily to humans via the domesticated animals. This is the first report of ticks infesting domesticated and wild animals carrying spotted fever rikettsia and it underscores the possibility of spread of infection from wild reservoirs to human in the animal/human health interface.