A virulent form of MRSA could combine with the swine flu virus with devastating effects, according to a paper in this week’s Lancet Infectious Diseases.
Community-acquired MRSA (CA-MRSA) appears to occur most commonly following an influenza-type illness, according to Dr Alicia Hidron, from the Emory University School of Medicine in Atlanta, Georgia.
Many colleagues report that published cases of CA-MRSA precede a flu-like illness and generally affect young and previously healthy patients.
Symptoms of CA-MRSA include high fever, low blood pressure and rapid progression to septic shock, with urgent need for mechanical ventilation. Mortality rates in the US are greater than 50%, according to reports from US and Europe.
The journal’s paper discusses two recent cases caused by the MRSA strain USA300, the most common cause of CA-MRSA infections in the US.
Most CA-MRSA produce panton valentine leukocidin (PVL), a toxin that can kill white blood cells and increase inflammatory response, which has been linked to lethality of CA-MRSA pneumonia.
Authors write: ‘The spectrum of disease caused by CA-MRSA occurs worldwide and primarily encompasses skin and soft-tissue infections…[However] severe infections such as necrotising pneumonia and bacteraemia have also been reported.’