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Early acquisition of cytomegalovirus infection
C S Peckham1, C Johnson, A Ades
1Department of Epidemiology, Institute of Child Health, London.
Insights
Cytomegalovirus (CMV) infection is common in infants, often acquired from mothers who are seropositive or through breastfeeding. Virus shedding can persist for years, making early detection crucial.
Area of Science:
- Virology
- Pediatrics
- Infectious Diseases
Background:
- Cytomegalovirus (CMV) is a common viral infection in infancy.
- Congenital CMV infection can be difficult to distinguish from acquired infection without early urine screening.
Purpose of the Study:
- To investigate the incidence and risk factors of cytomegalovirus (CMV) infection in infants.
- To determine the duration of CMV shedding in infected infants.
Main Methods:
- Screening 253 infants for CMV in urine at birth and follow-up for one year.
- Assessing risk factors including maternal serological status and breastfeeding.
- Analyzing CMV isolates from mother's milk and infant's urine using restriction endonuclease digestion.
Main Results:
- CMV shedding was observed in 12% of infants at 3 months and 20% at 12 months; all infections were subclinical.
- Maternal seropositivity (33% infection rate) and breastfeeding (76% infant infection rate from infected milk) were major risk factors.
- CMV shedding persisted for at least three years in all infected infants studied.
Conclusions:
- CMV infection is prevalent in infancy, with maternal serostatus and breastfeeding being key transmission routes.
- Persistent CMV shedding highlights the importance of early diagnosis to differentiate congenital from acquired infections.
- Subclinical CMV infections are common and can have long-term shedding patterns.
Abstract:
Two hundred and fifty three infants were screened for cytomegalovirus (CMV) in the urine at birth and were followed up at regular intervals for one year. Twelve per cent (of 249) were excreting virus at 3 months, and 20% (of 234) at 12 months. In all cases infection was subclinical. The major factors determining risk of acquiring infection were the mother's serological state and whether the infant was breast fed. There was no association with social class, mother's age, or whether the child had been in a special care baby unit or a postnatal ward. By one year 33% (of 123) of infants of seropositive mothers had acquired CMV infection compared with 4% (of 123) born to seronegative mothers. Twenty per cent (17) of seropositive women who breast fed had virus isolated from their breast milk on at least one occasion, and 76% (13) of their infants became infected. In four mother-infant pairs comparison of CMV isolates from the mother's milk and the child's urine was made by restriction endonuclease digestion; in each pair infection had apparently occurred with the same strain of virus. All 13 infected infants followed up for three years were still shedding virus. Infection with CMV is common in infancy, and virus shedding persists for years. Congenital infection cannot be distinguished from acquired infection unless the presence of CMV in the urine is identified within three or four weeks after birth, even when clinical problems suggestive of congenital infection are present.