Are children with Down syndrome at increased risk of severe RSV infection?

Children with Down syndrome are at a significantly higher risk of developing severe respiratory syncytial virus (RSV) infections, according to a new study, but Immunoprophylaxis may help.

The report, published in Pediatrics, reviewed 12 studies from 10 different countries to investigate the risks of hospitalization and mortality in children with Down syndrome compared with general pediatric populations.¹ Researchers found that children with Down syndrome required longer hospital stays by nearly 5 days; had increased oxygen requirements during hospitalization and higher frequencies of mechanical ventilation; more often required intensive care unit (ICU) admissions; and needed more advanced medications than children in the control groups.

Respiratory syncytial virus is a common respiratory virus that often results in mild symptoms, according to the Centers for Disease Control and Prevention (CDC), but it can become serious in some populations-particularly young children and the elderly. The virus is responsible for about 2.1 million outpatient visits and nearly 58,000 hospitalizations each year, the CDC reports. The study authors note that respiratory infections are the most common cause for hospitalization in children with Down syndrome, in part because of anatomic and immunologic abnormalities present in this population that might complicate infections such as RSV.

José A. Castro-Rodriquez, MD, PhD, a pediatric pulmonologist and associate professor of pediatrics at Pontificia Universidad Catolica de Chile, Santiago, Chile, and coauthor of the study, says this study is important because Down syndrome is the most common chromosomal condition in the world, with an estimated 1 in 800 live births each year. The heightened risks for this population in RSV infection should be a consideration for pediatricians, he says.

“Children with Down syndrome are at a significantly higher risk of having severe RSV infections-higher hospital admission, mortality, length of stay, oxygen requirement, ICU admission, need for respiratory support, and additional medication use-than children without Down syndrome,” says Castro-Rodriquez. “Because Down syndrome is the most common chromosomal disorder worldwide and given that RSV is associated with about 28% of all acute lower respiratory tract infection episodes and 13% to 22% of all acute lower respiratory tract infection-related mortality in young children, the results of the current study carry high importance and consequences for public health.”

Prophylaxis for RSV

Although the study didn’t specifically investigate prophylaxis, it did review the use of prophylactic medication in the data review. Specifically, the study referenced the use of palivizumab, a humanized monoclonal antibody, that has been used for prophylactic treatment of RSV in high-risk pediatric populations. The report notes that palivizumab isn’t currently recommended by the American Academy of Pediatrics (AAP) for prophylactic routine use in children with Down syndrome who don’t have other risk factors such as congenital heart disease or chronic lung diseases because of insufficient data about its efficacy.

Researchers do, however, note that a recent Japanese study showed palivizumab to be both safe and effective in reducing hospitalizations when used as prophylaxis in children with Down syndrome without significant congenital heart disease. However, the research team concludes that more research is needed to determine whether using palivizumab as prophylaxis in this population would be appropriate.

“Any potential strategy to reduce RSV infection in children with Down syndrome could decrease their morbidity and mortality,” says Castro-Rodriquez. “However, more cost-utility studies used to determine the efficacy of RSV Immunoprophylaxis in this specific high-risk patient population need to be done.”

References:

1. Beckhaus AA, Castro-Rodriguez JA. Down syndrome and the risk of severe RSV infection: a meta-analysis. Pediatrics. 2018;142(3):e20180225. Available at: http://pediatrics.aappublications.org/content/142/3/e20180225.long?sso=1&sso_redirect_count=1&nfstatus=401&nftoken=00000000-0000-0000-0000-000000000000&nfstatusdescription=ERROR%3a+No+local+token. Accessed October 1, 2018.