What's Behind Many Pneumonia Cases

Pneumonia was most common among very young US children and may often be caused by viruses like respiratory syncytial virus

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

(RxWiki News) Pneumonia is often connected to the elderly, but the youngest among us might have an increased risk.

A new study from Centers for Disease Control and Prevention (CDC) researchers found that most childhood pneumonia cases in the US affected children younger than 5 and had viral causes.

"Pneumonia puts thousands of young children in the hospital each year at a cost in the US of about $1 billion, not to mention suffering of kids and hardship for their families,” said CDC Director Tom R. Frieden, MD, in a press release.

Pneumonia is an infection of the lungs that can be caused by several different factors — viruses (like the flu), bacteria (like Streptococcus pneumoniae) or fungi. The infection often causes trouble breathing, cough and fever. It can range from mild to severe. Vaccines can help prevent pneumonia, and several medications can help fight off the infection.

In this new study, Seema Jain, MD, of the CDC in Atlanta, and colleagues wanted to explore cases of pneumonia among children in the US. Dr. Jain and team focused on community-acquired cases of pneumonia — that is, cases that developed outside health care facilities like hospitals.

These researchers used data from three US hospitals located in Memphis, Nashville and Salt Lake City.

A group of nearly 2,400 pneumonia patients younger than 18 with no recent hospitalizations or major immune system issues was identified between January 2010 and June 2012. About half of these children had an underlying condition like asthma.

Dr. Jain and team estimated that there were 15.7 cases of pneumonia a year per every 10,000 children in the US during the study period.

Most of the patients (70 percent) were younger than 5. Children younger than 2 had the highest rate of pneumonia when compared to other age groups.

When looking at children younger than 2, the estimated annual rate was 62.2 cases of pneumonia per 10,000 children.

Of the pneumonia patients, 21 percent needed intensive care treatment and less than 1 percent died.

Dr. Jain and colleagues collected samples from more than 2,200 of the study patients to determine the type of pneumonia they had. Of these, 81 percent had an identifiable pathogen — or infectious agent — that could have caused the pneumonia.

These researchers found viruses in 66 percent of these children. In 8 percent of the kids, Dr. Jain and team found bacteria. And 7 percent of these children had both viruses and bacteria that could have caused the pneumonia.

Respiratory syncytial virus, found in 28 percent of the samples, was the most common pathogen detected. There is currently no vaccine for this common virus, which often causes cold symptoms but can develop into more serious issues like pneumonia.

In a press release, Dr. Jain said this study might motivate the development of new treatments and vaccines to protect children against pneumonia.

"It also highlights the importance of using existing treatments and vaccines, such as those against pneumococcus and influenza,” Dr. Jain said.

This study was published Feb. 26 in the New England Journal of Medicine.

The National Center for Immunization and Respiratory Diseases funded this research. Dr. Jain and team disclosed no conflicts of interest.

Review Date: 
February 26, 2015
Last Updated:
February 27, 2015