EPIDEMIOLOGY OF CONGENITAL CYTOMEGALOVIRUS-INFECTION - MATERNAL RISK-FACTORS AND MOLECULAR ANALYSIS OF CYTOMEGALOVIRUS STRAINS

To determine factors that influence the occurrence of congenital cytom egalovirus (CMV) infection, the authors surveyed prospectively 8,254 i nfants born in eastern Iowa between October 1989 and June 1994. The au thors conducted a case-control study to identify maternal risk factors , matching each CMV-infected infant with three uninfected infants acco rding to hospital and date of birth. CMV strains were compared by usin g the polymerase chain reaction (PCR) to identify common sources of in fection. Of the 7,229 infants cultured successfully for CMV, 35 (0.48% ) were congenitally infected. Mothers of CMV-infected infants were mor e likely to be single (odds ratio (OR) = 3.05, p = 0.016), to work in sales (OR = 4.93, p = 0.008), or to be students (OR = 5.01, p = 0.017) . Conversely, women who worked in health-care professions were less li kely to have a congenitally infected infant (OR = 0.14, p = 0.049), PC R analysis indicated 27 distinct strains of CMV, but two groups of inf ants (two infants per group) excreted strains with indistinguishable m olecular patterns. One of these pairs of infants had older siblings wh o attended the same child-care center during their mothers' pregnancie s. The authors concluded that demographic and occupational factors inf luenced the risk of giving birth to an infant with congenital CMV infe ction. Many distinct CMV strains were identified, suggesting that majo r point source outbreaks had not occurred. Nonetheless, point source a cquisition of CMV from child-care environments did account for some ca ses of congenital CMV infection in eastern Iowa.