Public Health England is asking vets and nurses to help share information on imported ticks with the general public.
This follows the UK's first report of the brown dog tick Rhipicephalus sanguineus overwintering in residential properties.
While this is the first known case of the species overwintering indoors in the UK, it was suggested this may be possible when pet travel rules changed in 2012 - removing the requirement for compulsory tick treatments.
Writing in Vet Record (Vol 177 No 6), Kayleigh Hansford from Public Health England (PHE) and Richard Wall from the University of Bristol provide an update on two recent cases of imported ticks.
A house infestation with R. sanguineus was reported in Essex in 2014, following the importation of a dog from Spain.
Ticks are still being found in the property despite repeated treatments of the house and resident dogs. The authors say this suggests the ticks have been allowed to establish and overwinter in the property, presenting a potential disease risk to the pets and owners living there.
A second infestation was reported in a different house in Leicestershire in May last year. This case involved a dog imported from Cyprus, who was fostered at the property for three weeks, during which time the owner consulted a vet regarding an open wound on the dog.
Ticks were noted on the pet but there was no discussion of imported ticks and no information is available on whether the dog had been treated for ticks before travel.
After treatment, the dog was rehomed and, two months later, ticks were found inside the foster home. From July-October 2014, ticks were removed from the owner's own dogs on a daily basis, despite the fact that a tick treatment had been applied.
The resident of the house eventually imported insecticide from the US, which appeared to reduce the number of ticks. However, tick activity was once again found in the property this spring.
The University of Bristol was contacted and samples submitted as part of the Big Tick Project, which confirmed R. sanguineus. Subsequently, samples were sent to PHE's tick recording scheme (TRS), which also identified R. sanguineus, confirming the infestation and overwintering of the ticks.
PHE has thanked vets and nurses for submitting samples to the TRS, which has allowed it to identify 15 importation events involving R. sanguineus.
Vets and nurses are encouraged to continue submitting samples and to contact email@example.com with any suspicions regarding imported ticks.
PHE has also created an information poster for pet owners who may be travelling with or importing dogs into the UK. Practices are asked to help share this information by displaying the poster in their waiting rooms (download here: https://www.gov.uk/tick-recording-scheme#imported-ticks.) and discussing the risks of travelling with and importing pets with clients.