Respiratory viruses are much more likely to cause pneumonia in kids than bacterial infections, according to new research published in the Feb. 26 New England Journal of Medicine. The study, Etiology of Pneumonia in the Community (EPIC), was conducted by researchers from the Centers for Disease Control and Prevention (CDC) and three medical centers in Memphis, Nashville and Salt Lake City.
“Pneumonia puts thousands of young children in the hospital each year at a cost in the U.S. of about $1 billion, not to mention the suffering of kids and hardship to their families,” CDC Director Tom Frieden, MD, MPH, said in a news release. “This ground-breaking study shows how badly we need faster, less-expensive diagnostic tests for doctors to accurately diagnose the cause of pneumonia so they can effectively treat it.”
A general term for an infection of the lungs, pneumonia is the leading cause of hospitalization among children in the United States. Children under the age of 5 make up 70 percent of the admissions. “Despite the large burden of the disease,” wrote the study authors in the introduction, “critical gaps remain in our knowledge about pneumonia in children.”
To address those gaps, the EPIC researchers tested body fluid samples from 2,200 children treated for pneumonia in three children’s hospitals from January 2010 to June 2012. The median age of the children in the study was 2 years. Among the study group, 497 required intensive care and three died.
Findings showed that one or more viruses were detected in 66 percent of the children. Bacteria was found in 8 percent of the participants and 7 percent had both viruses and bacteria in their systems.
Among the identified viruses, respiratory syncytial virus (RSV) was most common, occurring in 28 percent of the children. It was also associated with the highest incidence of pneumonia in children under age 2. The human rhinovirus – the leading cause of the common cold – was detected in 22 percent of the cases.
The authors attributed the decline in bacterial pneumonia to the widespread use of vaccines that prevent bacterial infection. William Schaffner, MD, an infectious disease specialist at Vanderbilt University and spokesperson for the Infectious Disease Society of America, agreed.
Thirty or 40 years ago, “bacterial causes would have been predominant,” Schaffner, who was not involved in the study, told HealthDay. “What’s changed is that now we have vaccines that prevent bacterial pneumonia.”
Schaffner also sees the findings as emphasizing the importance of keeping children up-to-date on recommended vaccinations. The CDC reports that other standard vaccines, including shots against measles, whooping cough and chicken pox, can also reduce children’s risk of getting pneumonia.
“Effective antiviral vaccines or treatments, particularly for RSV infection, could have a mitigating effect on pneumonia in children,” the authors wrote in the study conclusion.