Seroprevalences of herpes simplex virus type 1 and type 2 among pregnant women in the Netherlands

Background: In the Netherlands 73% of cases of neonatal herpes are caused by herpes simplex virus type 1 (HSV-1), whereas in the United States a majority are caused by HSV type 2 (HSV-2). Goal: To understand this difference we undertook a sero-epidemiological study on the prevalence of HSV-1 and HSV-2 among pregnant women. Study Design: Type-specific antibodies to HSV-1 and HSV-2 were detected by enzyme-linked immunosorbent assay (ELISA) in serum samples from 1507 pregnant women in Amsterdam, Rotterdam, and Nijmegen. Results: The prevalence of HSV-1 was 61% in Nijmegen, 73 % in Amsterdam, and 75 % in Rotterdam. The prevalence of HSV-2 was 11 % in Nijmegen, 35 % in Amsterdam, and 27 % in Rotterdam. Conclusion: The seroprevalence of HSV-1 and HSV-2 antibodies among pregnant women in the Netherlands shows significant geographical differences, which were attributed to ethnical variation. However, the epidemiologic differences did not correlate with the incidence of neonatal herpes in the Netherlands.