RSV Not as Dangerous as Once Thought

Respiratory syncytial virus may pose less of a threat to babies than past research suggested

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) Good news for parents: babies face much less of a threat from respiratory syncytial virus, or RSV, than was once thought.

Although the disease can still threaten the health of infants and young children, a new study from the University of Utah found that even more babies survived the virus than most health professionals thought.

"I am not sure that [pediatricians] feel that children with RSV infections survive less often, but we do consider it a serious infection," said Thomas Seman, MD, a pediatrician at North Shore Pediatrics in Danvers, MA.

Survival rates for RSV have always been relatively high, especially in healthy babies, who are most often able to fight off the infection with medical support.

The authors of this new study noted that, in addition to providing reassurance to parents, this new study may help doctors determine whether and when to use expensive medicines to treat RSV.

“The news is very good for parents and their babies,” said lead study author Carrie L. Byington, MD, professor of pediatrics at the University of Utah in Salt Lake City, in a press release. “Although RSV is one of the most common causes for infant hospitalizations, we can support infants through this infection. Most hospitalizations will be 2-3 days with infants expected to recover fully.”

RSV can be a life-threatening disease for infants and young children. Past research indicated that most babies survived, but health care professionals were concerned about those few deaths that did occur. The research on survival rates was done decades ago, however, and had not been updated.

Children who have RSV typically have symptoms similar to those of a cold, but the disease can quickly progress to cause swelling of the airways and pneumonia. In babies younger than 6 months, hospitalization may be necessary.

"RSV can cause a severe pneumonia and is a leading cause of wheezing in children less than 2 years old. Both of these result in an increased risk of hypoxemia (low blood oxygen levels)," said Dr. Seman, who was not involved in this study.

"RSV is also known to cause apnea (or lack of breathing) in children by as of yet unknown mechanisms and is the presenting symptom is 20 percent of children under 1 years old," he explained. "Nonetheless, it can be seen in children under 6 years of age. At the present time, these symptoms cause many children to be hospitalized for up to a week. Recent studies have shown that over two thirds of all patients with RSV have at least one other infection in the lungs, as well. Most of these are other viral infections, but there is an increase in bacterial lung infections.

"Post-infection wheezing can last for up to the first 2-3 years, especially when the child gets another viral infection. This wheezing increases the incidence of pneumonia in the child and days out of work for the parents," he said. "So yes, the study shows that the incidence of mortality (death) may be lower than most expected; however, the relative morbidity (conditions resulting from initial infection) can be longer than the disease itself."

Today, babies are 100 times more likely to survive RSV than when the original research on RSV was published, Dr. Byington and team found.

Babies who were born prematurely, those who have lung conditions and those born with heart problems do face a higher risk from RSV. Babies who have immune system problems also face raised risks.

Dr. Byington and team focused on children younger than 2. They used the Healthcare Cost and Utilization Project Kids’ Inpatient Database (KID) for 2000, 2003, 2006, and 2009 and the Pediatric Health Information System (PHIS) administrative data from 2000 to 2011.

The KID database showed a total of 607,937 hospital admissions for RSV or related problems and 550 deaths during that time. In the PHIS database, those figures were 264,721 and 671, respectively. These figures represent very high survival rates.

The PHIS database showed that more children survived RSV over time, with 14 deaths per 100,000 children in 2002 and 4 per 100,000 children in 2011.

Data from both databases showed that healthy children handled RSV infections much better than those with complex, chronic medical conditions or other problems like severe infections. This dramatic increase in survival rates is likely due to medical care advances since the original studies were performed.

This new information may guide treatment, especially since medication to prevent RSV hospitalizations is very expensive, Dr. Byington and colleagues noted.

This study was published Dec. 8 in Pediatrics.

The National Institutes of Health and the H.A. and Edna Benning Presidential Endowment funded the research. The authors did not report any conflicts of interest.

Review Date: 
December 9, 2014
Last Updated:
December 15, 2014