Congenital cytomegalovirus infection in Canada: Active surveillance for cases diagnosed by paediatricians

To determine the rate of diagnosis; demographic, clinical and laboratory characteristics; and management of congenital cytomegalovirus (cCMV) cases identified by paediatricians in routine clinical practice in Canada.

National active monthly surveillance of all clinically practicing general and subspecialty paediatricians in Canada was performed for cCMV from March 1, 2005 to February 28, 2008, through the Canadian Paediatric Surveillance Program.

Forty-nine cases of cCMV infection were reported (4.5 per 100,000 births): 40.8% were born before 36 weeks' gestation; 55.1% had a birth weight <2500 g; and 28.6% and 30.6% were below the third percentile for weight and head circumference, respectively. The median maternal age was 23 years, and 18.4% were <20 years of age. Eight mothers (16.3%) were Aboriginal (non-Aboriginal birth prevalence 3.9 per 100,000; Aboriginal birth prevalence 15.8 per 100,000; P<0.005). The most common laboratory abnormality was thrombocytopenia (53.1%). Thirty-three (67.3%) infants exhibited neurological manifestations; ganciclovir therapy was administered to 12 (36.4%) and was not administered to 21 (63.6%) of the infants with neurological manifestations.

Only a minority of the expected number of symptomatic cCMV-infected infants were reported in the present study. The majority of these severely affected infants, including those with neurological disease, are not being treated with ganciclovir. The present description of current diagnosis and practice highlights the need for more complete case identification in the population as well as the need for increased awareness of the optimal therapy for symptomatic cCMV.