Serologic evidence for tick-borne pathogens other than Borrelia burgdorferi (TOBB) in Lyme borreliosis patients from midwestern Germany

The seroprevalence of antibodies against the human granulocytic ehrlichiosi s agent (HGE) and Babesia microti was retrospectively determined in 76 Lyme borreliosis patients and in 44 asymptomatic individuals with a positive bo rreliosis serology, in comparison to 100 healthy blood donors from the Rhei n-Main area. Additionally, seroreactivity for tick-borne encephalitis virus (TBEV) was investigated. For antibody detection, commercially available im munofluorescence assays (MRL Diagnostics, USA) and a TBEV-ELISA (Immuno, Ge rmany) were used. In the control group, the positivity rate for anti-Borrel ia burgdorferi (IgG/IgM) and anti-Babesia microti-antibodies in the populat ion of the Rhein-Main area (Midwestern Germany) may be estimated at 15% and 8%, respectively. Examination for both HGE and TBEV demonstrated seroreact ivity (IgG) in 1% of tested individuals. Specific anti-HGE IgG and/or IgM a ntibodies were more often discovered in cases of early Borrelia infection ( stage I: 13.6%, stage II: 18.4%) than in patients with stage III disease (0 %) or in seropositive but asymptomatic patients (6.8%). Investigation for T BEV revealed seroreactivity for IgG in 13% of these cases. No TBEV-IgM was found. Interestingly, the prevalence of anti-HGE and anti-TBEV antibodies a mong Lyme borreliosis patients and seropositive patients without active Lym e disease symptoms was significantly higher than that in the control group of healthy blood donors (p<0.05). Likewise, antibody titers reflecting a re cent infection with Babesia microti could be demonstrated more often in pat ients with Lyme borreliosis stage I or ii (p < 0.05). Analysis of 50 sample s from patients with florid or recent syphilis infection revealed no crossr eactivity between Babesia microti, HGE and Treponema pallidum. Our findings suggest that concomitant or serial infection due to TOED may be common in tick exposed patients from the Rhein-Main area and in European countries in general. Hence, in addition to TBEV, human babesiosis and HGE should alway s be considered by European physicians in the differential diagnosis of acu te febrile illness following a tick bite.