Seroprevalence of hepatitis E virus (HEV) in a general adult population in Northern Norway: the Tromsø study.

Hepatitis E virus (HEV) is a major cause of acute viral hepatitis in many parts of the world but only a few cases have been diagnosed in Norway. To investigate the HEV exposure rate in a presumed low-risk area, we have conducted a population-based study of anti-HEV IgG seroprevalence in Northern Norway. A total of 1800 serum samples from 900 women and 900 men, age 40-79 years, were randomly selected from the 21,083 participants in the 7th Tromsø Study, representing the 32,591 inhabitants of the Tromsø municipality that were ≥ 40 years. All samples were analyzed by ELISA-1 (recomWell HEV IgG). Samples testing positive or borderline, as well as a 1.5-fold excess of negative samples, were retested by ELISA-2 (DiaPro HEV IgG). If still borderline or a result discordant from ELISA-1, the sample was retested by ELISA-3 (Wantai HEV IgG) and strip-immunoassay (recomLine HEV IgG). Anti-HEV IgG was detected in 205 individuals (11.4%), yielding an estimated seroprevalence of 10.4% in the age-matched population of Tromsø. Using logistic regression analysis followed by multivariable backward elimination analysis, increasing age (OR 1.036 per year; p < 0.001) and higher education (OR 2.167; p < 0.001) were found as potential risk factors, whereas travel abroad or eating of red meat were not. Our results indicate that HEV-infection is common in Northern Norway and suggest that HEV testing should be included in the evaluation of elevated liver enzymes.