Seroprevalence of Borrelia IgG antibodies among individuals from Eastern Slovakia

Lyme borreliosis is a tick-borne disease of increasing incidence and public concern. Our cross-sectional study was aimed at evaluating seroprevalence of Borrelia burgdorferi in a group of respondents from Eastern Slovakia.

In total, 515 blood samples collected in 2013-2016 were analysed with NovaLisaTM, NovaTec - Borrelia IgG/IgM kit (Immunodiagnostica, Dietzenbach, Germany). Positive and equivocal IgG-antibody results were further examined with immunoblotting (LYMECHECK® OPTIMA IgG and IgM kits, BIOSYNEX, France). Data detected by serological methods were matched with those obtained from a questionnaire. Differences between groups by residence/seropositivity were tested by χ² test. The effect of socio-demographic and risk factors on seropositivity of IgG antibodies was assessed using binary logistic regression.

IgG antibodies against Borrelia burgdorferi were detected in 67 cases (13.01%) and IgM antibodies in 40 cases (7.8%). Previous tick bite had been noted in 67.2% of these seropositive individuals. Higher seropositivity was observed in men and persons aged over 61 years. Rural residents had higher seropositivity (39%) than those living in urban (29%) areas. Very few of these seropositive persons reported prior symptoms.

The study reveals that IgG-seropositivity for Borrelia burgdorferi in Eastern Slovakia is predominant in men and occurs mainly in rural areas. The findings also suggest that exposure to Borrelia burgdorferi (with subsequent antibody response in serum) does occur, mostly without giving rise to clinical Lyme borreliosis.