THE VALUE OF SEROLOGICAL TESTING FOR LYME-DISEASE IN THE UK

Although the prevalence of Lyme disease (LD) in the UK is low, patient s with clinical presentations compatible with the condition are common . Arthritis often complicates LD in North America, however it is a ver y rare complication of the condition in the UK. Many patients seen at St George's Hospital, London have visited endemic areas for LD within the UK, Europe and North America. To determine the value of serologica l testing for LD in the UK, we prospectively studied 120 patients seen at this hospital with clinical manifestations suggestive of LD (12 of whom were recruited to the LD clinic from outside the hospital catchm ent area), regardless of whether an alternative diagnosis seemed likel y. A history of tick bite was obtained and serum antibodies to Borreli a burgdorferi detected initially by enzyme-linked immunosorbent assay (ELISA) and reactive samples immunoblotted to further assess antibody specificity. Tick bites were reported by 22 patients, 16 of whom were bitten in endemic areas for LD. A further 11 patients had exposure to tick habitats in endemic areas, but were unaware of a tick bite. Raise d antibody levels were detected by ELISA in 14 individuals (seven of w hom had a history of tick bite or tick exposure in an endemic area); h owever, only four of these had specific antibodies to B. burgdorferi c onfirmed on immunoblot. All of these four had a history of tick bite i n an endemic area, all had arthritis and in three of the four, this wa s the only manifestation of the condition. These data indicate that (1 ) serological testing for LD is only of value in patients with a histo ry of exposure to tick habitats in an endemic area, (2) ELISA is a use ful screening test, although it lacks specificity and reactive specime ns should always be further examined by immunoblot and (3) in some pat ients in the UK, arthritis may be the sole manifestation of Lyme disea se and a high degree of diagnostic awareness is therefore required to recognize these cases.