Borrelia burgdorferi serosurvey in wild deer in England and Wales.

Lyme disease is the most common vector-borne disease in the United Kingdom and its incidence has been increasing in recent years. However, limited information is available on its epidemiology and dynamics in the U.K. A survey in wild deer to investigate the presence of antibodies reactive to Borrellia burgdorferi was conducted to obtain initial information on the distribution pattern of the spirochete in England and Wales. Samples from roe deer (n=604) and red deer (n=80) were collected in eight different locations. An ELISA protocol was developed to identify antibodies reactive to B. burgdorferi s.l. Seropositivity was investigated by location of sampling, over time, and in relation to the level of deer tick infestation. Twenty-three percent of animals had a positive serology. Seroprevalence varied according to location with the southern forestry districts showing higher seroprevalence rates. One northern location showed an unexpectedly high proportion of positive deer. Variations in the proportion of positive animals were also observed over time. Tick load was higher from spring through autumn, and its relation to seroprevalence was compatible with higher tick infectivity during the spring and summer months. This study represents the first assessment of distribution of Borrelia antibodies in deer in the U.K. and identifies areas that are potential hot spots for human Lyme borreliosis. Targeted epidemiological studies should be conducted to evaluate the actual disease risk for humans.