Seroepidemiology of cytomegalovirus infection among children between the ages of 4 and 12 years in Taiwan

Abstract

To determine risk factors responsible for primary cytomegalovirus (CMV) infection in Taiwan, samples of blood for antibody to CMV were obtained from 362 children aged 4 to 12 years: 58% were found to be positive for anti-CMV IgG antibody. Logistic regression analysis showed that seropositivity correlated with age, method of delivery, duration of breast feeding, and younger age of mother. Neither socioeconomic status nor crowded living conditions showed significant correlation with CMV seropositivity. Primary CMV infection in Taiwan appears to be less related to socioeconomic status shown in western countries, and, since the majority of pregnant women were seropositive in Taiwan, two of the major sources of primary CMV transmission are infected breast milk and the infected genital tract.

PIP: Researchers analyzed seroepidemiologic data on 362 4-12 year old public school children living in metropolitan Taipei, Taiwan to determine risk factors for cytomegalovirus (CMV) infection. 58% of the sera tested positive for anti-CMV IgG antibodies and 0.6% for anti-CMV IgM antibodies. None of these children had had any CMV-related diseases or cytomegalic inclusion disease related syndromes. The logistic regression analysis indicated that the most significant risk factor for CMV seropositivity was duration of breast feeding. Specifically children who had been breast fed for 24 months were 2.43 times more likely to be CMV seropositive than were those who had been breast fed for =or 24 months (p=.0001). The researchers believed that breast milk transmits the reactivating latent CMV to infants. Children whose mothers delivered them vaginally were at 2.2 times the increased risk of being CMV seropositive than were those were delivered by a Cesarean section (p=.012). This supported the belief that infants are more likely to be exposed to CMV during vaginal delivery than during Cesarean delivery. Other significant risk factors were older age (=or 7 years, risk ratio=1.61; p=.003) and younger mothers (=or 25 years, risk ratio=1.54; p=.025). Socioeconomic status, day care, or crowded living conditions were not associated with CMV seropositivity. These results indicated that primary CMV infection among children in Taiwan is due to natal or postnatal infection (infected genital tract and infected breast milk) instead of congenital transmission as is the case in developed countries.