Association of 2009 Pandemic Influenza A (H1N1) Infection and Increased Hospitalization With Parapneumonic Empyema in Children in Utah

[tetano]

Pediatric Infectious Disease Journal:
October 2010 - Volume 29 - Issue 10 - pp 905-909
doi: 10.1097/INF.0b013e3181df2c70
Original Studies
Association of 2009 Pandemic Influenza A (H1N1) Infection and Increased Hospitalization With Parapneumonic Empyema in Children in Utah
Ampofo, Krow MD*; Herbener, Amy MD*; Blaschke, Anne J. MD, PhD*; Heyrend, Caroline BSc?; Poritz, Mark PhD?; Korgenski, Kent MS*; Rolfs, Robert MD?; Jain, Seema MD?; Carvalho, Maria da Gl?ria PhD?; Pimenta, Fabiana C. PhD?; Daly, Judy PhD∥; Mason, Edward O. PhD**; Byington, Carrie L. MD*; Pavia, Andrew T. MD*




Background: During previous influenza pandemics, many deaths were associated with secondary bacterial infection. In April 2009, a previously unknown 2009 influenza A virus (2009 H1N1) emerged, causing a global influenza pandemic. We examined the relationship between circulating 2009 H1N1 and the occurrence of secondary bacterial parapneumonic empyema in children.

Methods: Children hospitalized with parapneumonic empyema from August 2004 to July 2009, including a period when the 2009 H1N1 circulated in Utah, were identified using International Classification of Diseases, Ninth Revision codes. We compared the average number of children diagnosed with influenza A and the number of admissions for empyema per month for the previous 4 seasons to rates of empyema during the 2009 H1N1 outbreak. We identified causative bacteria using culture and polymerase chain reaction (PCR).

Results: We observed an increase in hospitalization of children with pneumonia complicated by empyema during a severe outbreak of 2009 H1N1 during the spring and summer of 2009, compared with historical data for the previous 4 seasons. Streptococcus pneumoniae and Streptococcus pyogenes were the predominant bacteria identified.

Conclusions: Similar to previous pandemics, secondary bacterial infection with S. pneumoniae and S. pyogenes were associated with the 2009 H1N1 outbreak. There is an urgent need to better understand bacterial complications of pandemic influenza. In the interim, influenza vaccines, antiviral agents, and pneumococcal vaccines should be used to prevent cases of secondary bacterial pneumonia whenever possible.


http://journals.lww.com/pidj/Abstra...on_of_2009_Pandemic_Influenza_A__H1N1_.4.aspx

 

[tetano]

The researchers analyzed data on children diagnosed with empyema at Primary Children's Medical Center in Salt Lake City from 2004 to 2009. Empyema is an infection involving the pleural tissues surrounding the lungs, most often occurring as a complication of pneumonia. Empyema is a serious condition, frequently requiring a chest tube or surgery to drain infected fluid from the chest.

During the last three months of the study period?the spring and summer of 2009?there was a severe outbreak of H1N1 influenza in Utah. During this time, 604 children were diagnosed with H1N1 infection. Of these, 117 were hospitalized?a rate of 19 percent.

From May through June, 2009, there was a significant rise in the number of children with empyema, compared to previous years. Twenty-one cases were diagnosed?nearly double the average of 10.8 cases during the same time of year in 2004 to 2008.

Cases of empyema peaked in June, 2009, when 12 cases are diagnosed. This compared to an average of 3.5 children with empyema per month in June of other years. (In a typical year, most cases of empyema occur during the winter months, when seasonal influenza and other respiratory diseases are at their peak.)

All of the children diagnosed with empyema during from May to June, 2009, had a "flu-like illness" before hospitalization. Most children with confirmed influenza were infected with H1N1. The most common bacterial causes of empyema were strep bacteria, including pneumococcal bacteria (Streptococcus pneumoniae).

In patients with influenza, pneumonia and other secondary bacterial infections can occur. Empyema is an uncommon but serious complication of pneumonia. Data on 2009 H1N1 pandemic in the United States suggest that secondary bacterial infections contribute to many deaths in patients with H1N1. With proper treatment for empyema, there were no deaths among the children in the Utah study.

The study can't prove any cause-and-effect relationship between H1N1 and the increase in children with empyema. However, the reported "temporal association" suggests that doctors should be alert for pneumonia, empyema, and other secondary bacterial infections in children with H1N1. Young children (along with older adults, pregnant women, and people with certain medical conditions) are a high-risk group for serious complications of H1N1 influenza.

"There is an urgent need to better understand bacterial complications of pandemic influenza," Dr. Ampofo and colleagues write. "In the interim, influenza vaccines, antiviral agents, and pneumococcal vaccines should be used to prevent cases of secondary bacterial pneumonia whenever possible."

http://www.newswise.com/articles/h1n1-flu-linked-to-serious-bacterial-infections-in-children