CYTOMEGALOVIRUS REINFECTION IN YOUNG-CHILDREN

Objective: To determine the frequency of reinfection with new cytomega lovirus (CMV) strains in children in group child-care environments. Me thods: Ninety-two CMV strains isolated serially from children attendin g child care centers were analyzed. Strains were obtained from 1986 to 1994, from 37 children attending one of six centers in the area of Ce dar Rapids and lowa City, lowa, The CMV isolates were analyzed by a po lymerase chain reaction-based algorithm using primers for the a-sequen ce, glycoprotein B, and major immediate early (MIE) genes of human CMV . The a-sequence polymerase chain reaction products were compared on t he basis of size, and products derived from glycoprotein B and MIE gen es were compared according to restriction fragment length polymorphism s. Results: Children were between 8 months and 5 years 7 months of age at the time of CMV isolation. The number of isolates ranged from 2 to 6 per child, and the intervals between the first and last CMV isolati on ranged from 11 weeks to more than 3 years, At least 7 (19%) of the 37 children had evidence of infection with more than one CMV strain. I n six of these children, reinfection with distinct strains was confirm ed by analysis of the MIE gene products of sequential CMV strains. Con clusions: Children who attend child care centers, like adults who are immunosuppressed or have multiple sexual partners, are at risk of bein g-reinfected with distinct CMV strains.