Assessing the risk of human granulocytic anaplasmosis and lyme borreliosis after a tick bite in Bavaria, Germany

To date, only isolated incidences of human granulocytic anaplasmosis (HGA) have been reported in Europe. However, entomological studies in Bavaria, Germany showed a prevalence of Anaplasma phagocytophilum of between 2 and 9.5% in the tick vector Ixodes ricinus. In this study we assessed the risk of pathogenic A. phagocytophilum infection after a tick bite in Bavaria. The seroprevalence of anti-Borrelia burgdorferi sensu lato (s.l.) antibodies was investigated as an indicator of past exposure, seroconversion as actual exposure of participants to ticks.