A light in the darkness: predicting outcomes for congenital cytomegalovirus infections

Congenital cytomegalovirus infection in high-risk Canadian infants: Report of a pilot screening study

OBJECTIVES

Congenital cytomegalovirus (cCMV) is the most common congenital infection; however, the epidemiology in Canada has not been recently examined. The present prospective study pilots tools for a population-based study of cCMV infection in Canada by determining the maternal seroprevalence and risk factors, the clinical characteristics and the incidence of cCMV using a variety of diagnostic tests in a cohort of high-risk infants in northern Alberta.

METHODS

All infants born at the Royal Alexandra Hospital in Edmonton, Alberta, from June 1, 2003, to May 31, 2004, were screened for the study. Eligible infants were those with very low birth weights (VLBWs) or small for gestational age (SGA). Maternal CMV serostatus was determined, and chart review and parental interviews were completed. Neonatal urine and throat cultures, and polymerase chain reaction (PCR) were performed. Dried blood spots (DBS) were tested for CMV by PCR.

RESULTS

In total, 213 infants were eligible for the study. Of these, 137 entered the study (79 VLBW and 58 SGA). Some families were not contacted for participation in the study due to neonatal deaths or early discharge. The mean age of the mothers was 27.6 years; 68% of the mothers were Caucasian and 16% were Aboriginal. The maternal CMV seroprevalence was 55%. Seropositivity was significantly associated with ethnicity (First Nations [100%]; Caucasian [34%]) and country of birth (outside Canada [94%]; Canadian born [45%]). The rate of cCMV was two in 137 (1.5%), with a rate of one in 79 (1.3%) for the VLBW infants and one in 58 (1.7%) for the SGA infants. Both had positive throat or urine specimens, but only the symptomatic infant was positive on DBS.

CONCLUSIONS

A cCMV screening program should be universal and routine to successfully screen all newborns. Maternal CMV seropositivity varies widely within the Canadian population. In the present pilot study, DBS PCR was not a sensitive screening tool and throat swab was the best screening specimen.

Case-control study of symptoms and neonatal outcome of human milk-transmitted cytomegalovirus infection in premature infants

OBJECTIVE

Preterm infants are at risk of acquiring human cytomegalovirus (CMV) infection through breast milk transmission, possibly leading to serious symptoms, as suggested by previous studies. Over a period of 8.5 years, we compared infants infected postnatally with CMV with noninfected controls to determine whether CMV infection transmitted through breast milk poses serious acute risks.

STUDY DESIGN

CMV monitoring included maternal serologic testing and biweekly viral culture and polymerase chain reaction in breast milk and infant urine. Clinical and laboratory test findings were assessed retrospectively in infected infants and controls matched for gestational age during the initial hospital stay.

RESULTS

Forty CMV-infected infants met the study criteria. They had lower minimal platelet and neutrophil counts and a higher frequency of C-reactive protein (CRP) elevations to 10 to 20 mg/L than their matched controls (P < or = .001). But no association of CMV infection with bronchopulmonary dysplasia, necrotizing enterocolitis, growth, or CRP elevations to > 20 mg/L was found. Cholestasis appeared in 3 infants in the CMV-infected group, but disappeared within 10 weeks.

CONCLUSIONS

Neonatal symptoms related to postnatal CMV infection were transient and had no affect on neonatal outcome in these infants, in contrast with uncontrolled reports. Whether withholding or pasteurizing breast milk is warranted, however, depends on long-term outcome.