It is important for a patient’s history of possible tick exposure to be taken into account. Lyme borreliosis is endemic throughout the UK and Ireland, although some areas pose a higher risk than others. The Health Protection Agency advises that any area that supports a hard tick population poses a risk. However, an assessment of tick exposure can be problematic as it is also recognised that ticks can be present in urban parks and gardens as well as rural areas. Bites may occur in places that are not considered to be risk areas. It has been highlighted by the World Health Organisation that, “In urban areas, nests of feral pigeons in the lofts of houses can result in invasions of soft ticks (such as the pigeon tick, Argas reflexus) into closely situated flats and apartments” and, “blackbirds in urban parks are carriers of infected ticks”. Other urban wildlife species, such as foxes and hedgehogs, can also carry and transport infected ticks.

A diagnosis can be problematic if the patient does not recall a tick bite. Over the last few years, epidemiological data from the Health Protection Agency has demonstrated that fewer than 50% of laboratory-confirmed cases of Lyme borreliosis reported a tick bite. It is therefore important to take into consideration a patient’s recreational and occupational activities.

Diagnosis can also be problematic if a patient is infected with other tick-borne pathogens concurrently (co-infections) as this may alter the way in which Borreliosis presents, as well as the way in which it should be treated.