Severe methicillin-resistant Staphylococcus aureus community-acquired pneumonia associated with influenza--Louisiana and Georgia, December 2006-January 2007.

Staphylococcus aureus infection has been reported infrequently as a cause of community-acquired pneumonia (CAP) and typically has been associated with influenza virus infection or influenza-like illness (ILI). During the 2003-04 influenza season, methicillin-resistant S. aureus (MRSA) gained attention as a cause of 15 cases of influenza-associated CAP. No formal surveillance has been conducted, and few additional cases of MRSA CAP were reported to CDC during the 2004-05 and 2005-06 influenza seasons. However, in January 2007, CDC received reports of 10 cases of severe MRSA CAP, including six deaths, among previously healthy children and adults in Louisiana and Georgia during December 2006-January 2007. These were the first reported cases of severe MRSA CAP during the 2006-07 influenza season in the two states, and 10 was a higher number than expected for the 2-month period. A case of severe MRSA CAP was defined as pneumonia requiring hospitalization or resulting in the death of a patient from whom a specimen (i.e., sterile site or sputum sample) yielded MRSA when collected <48 hours after hospitalization or arrival at an emergency department (ED). Association with influenza was determined by either a positive result on a laboratory test or a diagnosis of ILI. This report describes three of the MRSA CAP cases as examples and summarizes all 10 of the reported cases. These cases underscore the need for health-care providers to be vigilant, especially during the influenza season, for severe cases of CAP that might be caused by MRSA.