Cohort study on maternal cytomegalovirus seroprevalence and prevalence and clinical manifestations of congenital infection in China

Abstract

Congenital cytomegalovirus (CMV) infection is the leading viral cause of birth defects and developmental disabilities in developed countries. However, CMV seroprevalence and burden of congenital CMV infection are not well defined in China.Cohort of newborns from 5 birthing hospitals in 2 counties of Shandong Province, China, were enrolled from March 2011 to August 2013. Dried blood spots (DBS) and saliva were collected within 4 days after birth for IgG testing for maternal seroprevalence and real-time PCR testing for congenital CMV infection, respectively.Among 5020 newborns tested for CMV IgG, 4827 were seropositive, resulting in CMV maternal seroprevalence of 96.2% (95% confidence interval [CI]:95.6%–96.7%). Of the 10,933 newborns screened for congenital CMV infection, 75 had CMV detected, resulting in an overall prevalence of 0.7% (95% CI: 0.5%–0.9%), with prevalences of 0.4% (14/3995), 0.6% (66/10,857), and 0.7% (52/7761) for DBS, wet saliva, and dried saliva specimens screened, respectively. Prevalence of congenital CMV infection decreased with increasing maternal age (0.9%, 0.6%, and 0.3% among newborns delivered from mothers aged 16–25, 26–35, and >35 years, respectively; P = 0.03), and was higher among preterm infants than full term infants (1.3% vs 0.6%, P = 0.04), infants with intrauterine growth restriction (IUGR) than those without (1.8% vs 0.7%, P = 0.03), and twins or triplets than singleton pregnancies (2.8% vs 0.7%, P = 0.04). None of the 75 newborns exhibited symptomatic congenital CMV infection, and there was no difference in clinical characteristics and newborn hearing screening results between infants with and without congenital CMV infection at birth.Congenital CMV infection prevalence was lower and the clinical manifestations were milder in this relatively developed region of China compared to populations from other countries with similarly high maternal seroprevalence. Follow-up on children with congenital CMV infection will clarify the burden of disabilities from congenital CMV infection in China.

Viral Loads in Congenital Cytomegalovirus Infection From a Highly Immune Population

“…Among 75 newborns identified with congenital CMV infection from 10,933 newborns screened [2], mean viral loads in wet saliva (n = 66) and dried saliva (n = 52) specimens were 6.1 and 6.4 log 10 copies/mL, respectively. There was no difference between wet and dried saliva specimens ( P = 0.39) (Figure 1, Panel A), even the storage time before testing was longer for dried saliva specimens than for wet saliva specimens (74 vs. 58 days, P=0.02).…”

“…With approval from China Center for Disease Control and Prevention Ethics Committee, newborn screening for congenital CMV infection was conducted in five birthing hospitals in Shandong Province, China, from March 2011 through September 2013 [2]. All parents were approached to participate and approximately 98% of them enrolled.…”

“…All parents were approached to participate and approximately 98% of them enrolled. Specimen collection, storage, and PCR testing has been previously described [2]. Wet saliva specimens (maintained as wet and cold-stored and transported) were collected for the full study period of 2.5 years, while DBS specimens (dried overnight at ambient temperature, cold-stored and -transported) were collected concurrently for the first 12 months of the study only.…”

“…Paired comparison of viral loads between dried saliva and DBS was not performed because there were too few infants with both specimens collected. Maternal and newborn factors assessed in a prior report on congenital CMV infection [2] were further evaluated on their association with viral loads in different specimens using Student’s t -test or analysis of variance wherever appropriate. All analyses were performed with SAS V9.4 (SAS Institute, Cary, NC); statistical significance was defined as P < 0.05.…”

“…Saliva specimens have been shown to have higher sensitivity for detecting congenital CMV infection than dried blood spot (DBS) specimens in developed and developing countries [2, 3]. In the current study, we compared CMV viral loads in two different types of saliva specimens (wet vs. dried), in saliva compared to blood specimens from infants of population with high maternal seroprevalence in China.…”