Number of CP Children Infected by Cytomegalovirus May Be Greater Than Estimated

The number of children with cerebral palsy (CP) infected with the cytomegalovirus (CMV) — a virus believed to trigger the development of this disease in children — may be greater than previously thought, according to a new study.

The study reporting the findings, “Congenital Cytomegalovirus among Children with Cerebral Palsy,” was published in The Journal of Pediatrics.

CMV is a common virus among communities but, contrary to similar pathogens, it rarely causes symptoms in healthy people. Because it can stay undetected, it is difficult to know for sure how many people are infected.

CMV has been linked to CP by transmission from an infected mother to the developing fetus (congenital CMV infection), which increases the risk of birth defects and abnormal development of the fetus’ brain. It is estimated that congenital CMV infection affects nearly 0.7% of newborns, with 10-15%  showing signs of infection at birth, whereas an equal percentage of newborns have no signs at birth but will develop neurological and developmental anomalies while growing up.

“Despite this known association, and estimates of neurologic disability from congenital CMV, few reports describe the prevalence and epidemiology of cerebral palsy associated with congenital CMV,” said Cheryl Jones, PhD, senior author of the study, in a press release. “Defining the role of congenital CMV as a risk factor for cerebral palsy is important because it is the most common intrauterine infection in developed countries, is potentially preventable, and antiviral therapy postnatally can reduce the severity of adverse neurologic outcomes,” Jones said.

Researchers analyzed the newborn screening cards of 323 children with CP to investigate the rates of infection detection at birth. The team found that 31 (9.6%) tested positive for the presence of CMV in their blood. This finding was particularly impressive, given that the proportion of newborn children with CMV infection in the general population is below 1%.

This value also is six times higher than the proportion of CP cases believed to be due to congenital CMV included in the Australian Cerebral Palsy Register (1.5%), and greater than that obtained in a previous study with CP caucasian children (1.5%).

“This study serves as a timely reminder of the importance of CMV as a common intrauterine viral infection in developed countries and the potential for long-term consequences beyond the newborn period”, concluded Hayley Smithers-Sheedy, PhD, lead author of the study. “More research is needed to investigate the mechanisms and contribution of congenital CMV to the causal pathways to cerebral palsy,” she concluded.