The cease in the poularity of breast feeding and of child care t are having a major effect on the epideilogy ofcytomegalov infections. Under special circumstances fomites may also play a role, since CMV has been shown to retain infectivity for hours on plastic surfaces and has been isolated from randomly selected toys and surfaces in day-care centers (4, 5). Restriction enzyme analyses of CMV DNA have been used to demonstrate route oftransmission of the virus in situations in which close contact occurs, such as breast-feeding, sexual activity, day care, and interaction between parents or caretakers and infected toddlers.The prevalence of CMV infection increases with age, but, according to geographic, ethnic, and socioeconomic backgrounds, the patterns of acquisition of this infection vary widely among populations (6). As illustrated in Fig. 1, CMV is acquired earlier in life in developing countries and among the lower socioeconomic strata of developed countries. Differences between populations can be particularly striking during childhood. Presumably, these significant differences are the reflection of factors that account for increased exposure to CMV such as crowding, breast-feeding, sexual practices, and certain rearing practices.Studies carried out in the past 15 years indicate that breast-feeding and child-rearing practices singly or in combination are two of the most powerful factors influencing the rate of acquisition of CMV in the various populations (7,8 shedding CMV in colostrum while 13 of 31 (42%) had positive milk specimens when sampled between 2 and 12 wk postpartum. As illustrated in Table 1, the acquisition of CMV by Abbreviation: CMV, cytomegalovirus. *To whom reprint requests should be addressed.
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