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

Abstract

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.In the TBEV ELISA, five (0.4%) sera were positive. These were all interpreted as "false" positives, as four had received vaccines against flaviviruses, and the remaining was negative for neutralizing antibodies to TBEV.Antibodies to A. phagocytophilum were detected by indirect immunofluorescence in 49 (16.2%) subjects (titer range 80-1280).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.

Subjective health complaints are not associated with tick bites or antibodies to Borrelia burgdorferi sensu lato in blood donors in western Norway: a cross-sectional study

“…This investigation included a questionnaire in addition to testing serum samples for antibodies to B. burgdorferi s.l., tick-borne encephalitis virus and Anaplasma phagocytophilum . The reported occurrence of tick bites and the results of the antibody tests in this study population have been published elsewhere [ 18 – 20 ].…”

The Seroprevalence of Anaplasma phagocytophilum in global human populations: a systematic review and meta‐analysis

“…A major reason for heterogeneity in our review was the regional variation in A. phagocytophilum seroprevalence in Europe and America. Studies conducted in 13 European countries in this review (including Poland, Norway, the Czech Republic, Portugal, Sweden, Slovakia and Slovenia) had A. phagocytophilum seroprevalence estimates >10% (Chmielewska‐Badoraet al, 2012; Cisak et al, 2005; Cochez et al, 2011; Dvorakova Heroldova & Dvorackova, 2014; Henningsson et al, 2015; Hjetland et al, 2015; Kalinova, Halanova, Cislakova, & Juris, 2015; Kocianova et al, 2008; Rojko et al, 2006; Wass et al, 2018; Fingerle et al, 1997; Chochlakis, Papaeustathiou, Minadakis, Psaroulaki, & Tselentis, 2008; Zukiewicz‐Sobczak et al, 2014), with the highest estimate being 30.1%. In Europe, about 100 confirmed HGA cases have been described since its initial identification in Slovenia in 1997 (Petrovec et al, 1997).…”

Serological reactivity to Anaplasma phagocytophilum in neoehrlichiosis patients

“…Estimates of the seroprevalence of A. phagocytophilum antibodies in the general population in Scandinavia vary greatly. Two older studies report seroprevalence figures of 2.0 and 2.5% among Danish and Norwegian blood donors [ 15 , 16 ], but a newer Norwegian study gives a figure of 16% [ 17 ]. The estimates of the A. phagocytophilum seroprevalence in populations that are heavily tick-exposed range from 10% in Norway [ 15 ], 11–17% in Sweden [ 18 , 19 ], to 21% in Denmark [ 16 ].…”

“…The estimates of the A. phagocytophilum seroprevalence in populations that are heavily tick-exposed range from 10% in Norway [ 15 ], 11–17% in Sweden [ 18 , 19 ], to 21% in Denmark [ 16 ]. It should be noted that the more recent seroepidemiologic surveys have utilized the same IFA as in the present study, which is based on a human isolate of A. phagocytophilum [ 16 , 17 , 19 ], whereas the older studies have used an equine A. phagocytophilum isolate [ 15 , 18 ]. In contrast to the relatively high seroprevalence of A. phagocytophilum antibodies, there is a scarcity of case reports of anaplasmosis from the Scandinavian countries [ 20 , 21 ].…”