Serotype 19A of Streptococcus pneumoniae

19A Linked to Necrotizing Pneumonia

Pediatric News  Volume 42, Issue 12, Page 12 (December 2008)

 

WASHINGTON — Serotype 19A of Streptococcus pneumoniae is the culprit behind some complicated cases of necrotizing pneumonia in young children, based on findings from four cases that occurred between September 7, 2007, and March 30, 2008, at a single hospital.

“Severe necrotizing pneumonia caused by this serotype had not previously been reported in children,” explained Dr. Susan Wootton of the University of Texas, Houston, who presented the cases with her associates in a poster at the jointly held annual meeting of the Interscience Conference on Antimicrobial Agents and Chemotherapy and the annual meeting of the Infectious Diseases Society of America.

The 19A strain is one of several that are not included in the current pneumococcal conjugate vaccine, PCV7. Data from the Centers for Disease Control and Prevention that also were presented at the meeting showed an increase in invasive pneumococcal disease from nonvaccine serotypes in all age groups.

The four children ranged in age from 3 to 4 years (mean age, 3.4 years). Of these, three were previously healthy and one had asthma. All four had been vaccinated with PCV7. S. pneumoniae was isolated from pleural fluid in three cases and from blood in three cases.

Chest radiographs revealed multilobar infiltrates in four children, empyema in three children, and pneumatoceles in two children. Overall, three children were admitted to the intensive care unit and intubated 5–22 days, with an average of 11 days. In addition, three children had abscesses that required surgical drainage. The hospital stays ranged from 11 to 28 days (average stay, 19 days).

Serotype 19A has not previously been reported as a cause of complicated pneumonia in children, but these cases suggest that it should now be considered in the differential diagnosis, Dr. Wootton and her associates noted.

This study was limited by its small size and narrow geographical scope, and more research is needed to assess the large-scale impact of serotype 19A on necrotizing pneumonia. But the results support the need for an expanded pneumococcal vaccine for children in the United States, they said.

Dr. Wootton stated that she had no financial conflicts to disclose.

Advertisements