It wasn’t understood exactly why healthy children who fell ill with the H1N1 flu, during the 2009 epidemic, became critically ill. The Children’s Hospital in Boston has found one key risk factor is MRSA (methicillin-resistant Staphylococcus aureus). Those carrying the bacteria had eight times the risk of mortality amongst previously healthy children.

What’s more worrying is that the infections were more often than not detected and the children were treated with vancomycin, considered to be appropriate treatment for MRSA, but they died despite this treatment and it is especially alarming with the rising rates of MRSA among children in the community.

Study leader Adrienne Randolph, MD, MsC, of the Division of Critical Care Medicine at Children’s Hospital Boston said :

“There’s more risk for MRSA to become invasive in the presence of flu or other viruses … These deaths in co-infected children are a warning sign.”

Dr. Randolph clarifies that there is more risk of MRSA becoming invasive when the immune system is weakened fighting the flu, and goes on to raise the red flag on these MRSA / Flu deaths in children as the harbinger of worse to come.

The average age of the children in the study that had H1N1 was six. Many had respiratory failure and more than 60% needed mechanical ventilation with some requiring extracorporeal membrane oxygenation (ECMO) for advanced cardiac and respiratory support. The disease was aggressive and 75 children, around 9 percent of the study, died and of them around 50 within two weeks.

Dr. Randolph clarifies :

“It is not common in the U.S. to lose a previously healthy child to pneumonia … Unfortunately, these children had necrotizing pneumonia … eating away at their tissue and killing off whole areas of the lung. They looked like immunocompromised patients in the way MRSA went through their body. It’s not that flu alone can’t kill … it can … but in most cases children with flu alone survived.”

Recent studies point to a rise in the number of children carrying MRSA. A study in Pediatrics in 2010 found that the number of children hospitalized for MRSA infection increased from 2 in 1,000 admissions in 1999 to 21 in 1,000 admissions in 2008. This rise was attributed mostly to community-acquired cases … not cases acquired in the hospital.

Randolph and many others in her field agree that the increasing use of antibiotics is creating a situation where we are colonizing ourselves with more aggressive antibiotic resistant bacteria, which while not life-threatening in themselves are able to launch an aggressive infection once the presence of something like the flu has weakened the body sufficiently.

While recent data shows an increase in MRSA co-infection in children dying from seasonal influenza, this is the first study to collect data on a large number of children with no risk factors for severe flu.

Written by Rupert Shepherd