Pediatricians show excellent clinical judgment when it comes to targeting 32 to 35 week premature infants who would benefit from palivizumab (SynagisR) prophylaxis against respiratory syncytial virus (RSV) infection, new data suggest.

The results, presented at the annual meeting of the Pediatric Academic Societies (PAS), showed that infants in this age group in whom RSV prophylaxis was requested but not administered had a significantly higher RSV hospitalization rate than infants whose physicians did not request RSV prophylaxis.

“The findings support the notion that the identification of infants at high risk of RSV hospitalization and therefore prophylaxis should be the responsibility of the physician,” principal investigator Jessie Groothuis, M.D., Vice-President and Head, Medical and Scientific Affairs, Medimmune in Gaithersburg, Maryland, said.

Her team reviewed 3,876 medical records maintained by 382 pediatricians throughout the U.S. during a recent 2.5 year period in an effort to evaluate physician decision-making with respect to palivizumab and risk factors in the 32 to 35 week gestational age premature infant population.

“Infants 32-35 weeks gestational age comprise 70 percent of the preterm population and are at higher risk for RSV respiratory disease compared with term infants,” Dr. Groothuis pointed out. “Prophylaxis with the humanized monoclonal antibody palivizumab has been shown to decrease hospitalization due to RSV by 80 percent in infants 32 to 35 weeks gestational age.”

In 2003, the American Academy of Pediatrics (AAP) issued guidelines that endorse the use of palivizumab in high- risk infants 32 to 35 weeks gestation age who are less than six months of age at the start of RSV season provided they have at least two of five risk factors. These include attendance in day care, school age siblings, exposure to environmental pollutants, congenital airway anomalies, and severe neuromuscular disease.

Since then, additional risk factors have gained importance, including exposure to tobacco smoke, crowded living conditions (four or more in a household), and young chronologic age (age less than three months at the start of RSV season or being born during RSV season).

In the present study, 1,967 (50.8 percent) 32 to 35 week premature infants did not receive palivizumab prophylaxis. Of these, 1,429 (72.7%) infants were not referred by their physician for prophylaxis, and 528 (26.8%) infants were physician-referred for prophylaxis. The request status of 10 (0.5%) 32 to 35 week premature infants was unknown.

The group in whom RSV prophylaxis was requested but not administered had an RSV hospitalization rate that was nearly triple the rate of RSV hospitalization among infants whose physicians did not request prophylaxis (8.3 percent versus 2.9 percent, p

By Jill Stein
Jill Stein is a Paris-based freelance medical writer.
Jillstein03{at}gmail.com