Early acquisition of herpes simplex virus type 1 antibodies in children—A longitudinal serological study

Abstract

Background Herpes simplex virus type 1 (HSV-1) infections are commonly acquired in childhood, asymptomatically or as a symptomatic infection. However, little is known about the time of HSV seroconversion during infancy and early childhood. Objective To investigate the acquisition of IgG-antibodies to HSV in infants and children. Study design A longitudinal study, using type-specific HSV-1 and herpes simplex virus type 2 (HSV-2) enzyme-linked immunosorbent assays on sera collected from the mother and from their child at the age of 3, 5, 6, 12, 13 and 30 months. Results The maternal seroprevalences for HSV-1 was 65% and for HSV-2 19%. A gradual loss of maternal antibodies was seen, with few infants having detectable HSV-1 antibodies at the age of 1 year. A more rapid decline was registered for HSV-2 antibodies. A small number of new HSV-1 infections occurred in 3–5-month olds and more than half of the new infections were detected before the age of 13 months. At the age of 30 months, 30% of the children were HSV-1 antibody positive. Conclusion Seroconversion to HSV-1 commonly occurs already during infancy, suggesting that HSV-1 is transmitted primarily from parent to child.