Risk Factors for Congenital Cytomegalovirus Infection Following Primary and Nonprimary Maternal Infection

BACKGROUND: The design of diagnostic and preventive strategies have been prevented by gaps in knowledge of the epidemiology of congenital cytomegalovirus (cCMV) with the type of maternal infection as well as the lack of large-scale neonatal screening tools. METHODS: In sum, 11715 consecutive newborns were screened for cCMV by polymerase chain reaction (PCR) in saliva. Prevalence, type of maternal infection, sociodemographic, obstetrical, and serological data were analyzed. RESULTS: Positive predictive value of CMV PCR in saliva was 59%; false positive results were associated with lower viral loads (P < .001). Maternal seroprevalence was 61%, birth prevalence was 0.37%, resulting from primary and nonprimary infections in 52% and 47.7% of cases, respectively. The risk to deliver an infected baby after primary infection was increased in younger (OD = 7.9), parous (OD = 4.1) women born in high resources countries (OD = 5.2) and from higher income groups (P = .019). The only 2 risk factors to deliver an infected baby after nonprimary infection were to be young (OD = 4.6) and unemployed (OD = 5.8). The risk to deliver an infected baby was 4-fold higher in women seronegative before their pregnancy (P = .021). CONCLUSIONS: A positive CMV PCR in newborns' saliva should always be confirmed in a repeat-sample. Sociodemographic characteristics of women giving birth to an infected baby after primary and nonprimary infection are different. Seronegative, parous women represent the highest risk population for cCMV in countries with low to intermediate seroprevalence. Urgent action is needed to stop the cCMV's epidemic, particularly in this population easily identifiable by maternal serology and amenable to prevention messages. CLINICAL TRIALS REGISTRATION: NCT01923636.