Seroprevalence of antibodies to tick-borne encephalitis virus and Anaplasma phagocytophilum in healthy adults from western Norway

Abstract

<p>The aim of this study was to assess the seroprevalence of antibodies to tick-borne encephalitis virus (TBEV) and Anaplasma phagocytophilum in a healthy adult population from Sogn and Fjordane county in western Norway. Sera from 1, 213 blood donors were analysed for IgG-antibodies to TBEV, and a random subgroup of 301 donors for IgG to A. phagocytophilum.</p> <p>In the TBEV ELISA, five (0.4%) sera were positive. These were all interpreted as &ldquo;false&rdquo; positives, as four had received vaccines against flaviviruses, and the remaining was negative for neutralizing antibodies to TBEV.</p> <p>Antibodies to A. phagocytophilum were detected by indirect immunofluorescence in 49 (16.2%) subjects (titer range 80-1280).</p> <p>The results indicate that TBE currently is not endemic in this part of western Norway. However, there is serological evidence of the existence of human granulocytic anaplasmosis in the population.</p>