MRSA and Flu Can Overlap into Pandemic Proportions

The importance of MRSA in a flu pandemic by Maryn McKenna
Excerpted from her blog.

Constant readers will know that, in another part of my life, I write a great deal about seasonal and pandemic influenza, a subject I've been following since writing the first story in the American media about avian influenza H5N1. And people concerned about MRSA realize that flu and MRSA have an important overlap. For decades, long before the emergence of MRSA, staph was one of the most important contributors to secondary bacterial pneumonia, which occurs after the flu virus has damaged the lung tissue and allows staph and other bacteria to take hold.

In the past few years, we've been reminded of this interaction because of the shocking rise in cases of necrotizing pneumonia caused by MRSA. Twice in the past two years, the CDC has asked state health departments to report any cases of flu/MRSA co-infection; in the 2006-07 flu season, 22 children died from MRSA necrotizing pneumonia secondary to flu.

Comes now one of the giants of staph research to warn of an unconsidered danger of MRSA: as a contributor to deaths in a flu pandemic. Dr. Theodore Eickhoff, who wrote some of the earliest papers on hospital-acquired staph infections, has written an assessment in Infectious Disease News of two new pieces of research into deaths during the 1918 flu pandemic. Both papers contend that it was bacterial pneumonia that was the major killer in that global storm of death, and not the novel flu virus itself.

Eickhoff looks forward from those findings to consider what havoc a new pandemic could wreak in this era of massive MRSA transmission. He contends that national planning for pandemics — a huge effort and expense for the US and other governments over the past few years — has paid insufficient attention to the possibility that bacterial infection will be as significant a danger as whatever new flu has emerged:

Authors of both of these reports point out that their findings have important implications for pandemic preparedness today. U.S. preparedness policy, and indeed that of almost all other countries, has been focused on preventing or modifying influenza virus infection itself. Thus, vaccine development and anti-viral drugs (eg, neuraminidase inhibitors) have been the major efforts, and a great deal of stockpiling has already taken place.

Clearly it is equally necessary to stockpile antibiotics effective against primarily community-acquired organisms causing post-influenza pneumonia today, including both MSSA and MRSA. Much more consideration needs to be given to the possible role of pneumococcal and possibly other bacterial vaccines as part of pandemic preparedness.