Clinical manifestations of primary herpes simplex virus type 1 infection in a closed community.
 The clinical features and the molecular epidemiology of primary herpes simplex virus type 1 (HSV-1) infection among children younger than 3 years of age were investigated in day-care nursery.
 Serial sera were assayed for anti-HSV-1 glycoprotein B antibody by enzyme-linked immunosorbent assay.
 Serologic examinations revealed 55 cases of primary HSV infection during the observation period.
 Fifty-one of them (93%) had typical herpetic gingivostomatitis, showing a high rate of clinically overt infection.
 Four outbreaks of herpetic gingivostomatitis were observed during the observation period.
 Forty-one children were infected with HSV-1 in the outbreaks.
 The rates of infection in the susceptible children were 81%, 73%, 78%, and 100%, respectively, in the four outbreaks.
 Restriction endonuclease analysis of DNA of isolated HSV revealed that only one strain of HSV-1 had been transmitted among children for a long period.
