H1N1 influenza pandemic, many previously healthy children became critically ill, developing severe pneumonia and respiratory failure, sometimes fatal. The most important nationwide investigation up to now of influenza in critically ill children, led by Children’s Hospital Boston, found one key risk factor: Simultaneous infection with methicillin-resistant Staphylococcus aureus (MRSA) increased the chance for flu-related mortality 8-fold among previously healthy children.
Moreover, the majority of these co-infected children were rapidly helped by vancomycin, thought to be appropriate treatment for MRSA. The fact they died understandably treatment methods are especially alarming given the rising rates of MRSA carriage among children locally.
“There’s more risk for MRSA to be invasive within the presence of flu or other viruses,” says study leader Adrienne Randolph, MD, MsC, with the Division of Critical Care Medicine at Children’s Hospital Boston. “These deaths in co-infected children are a warning sign.”
The study hope their findings, published Nov. 7 from the journal Pediatrics, (eFirst pages) will promote flu vaccination among all children aged few months and older. (No flu vaccine is currently available for children younger than few months.)
“The 2009 H1N1 virus hasn’t changed significantly up to now,” notes Tim Uyeki, MD, MPH, with the Influenza Division from the National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention (CDC), a senior investigator about the study. “Infections of kids in the U.S. with 2009 H1N1 virus are anticipated there is much surprise and wish for being prevented and treated appropriately. Influenza vaccination protects against 2009 H1N1 illness.”
With emergency funding through the National Institutes of Health, Randolph and her colleagues from the Pediatric Acute Lung Injury and Sepsis Investigator’s Network tracked 838 children admitted to 35 pediatric ICUs throughout the country with probable 2009 H1N1 influenza from April 2009 to April 2010. Their vaccination status wasn’t consistently known, but H1N1 vaccine didn’t become available until September 2009 or later.
The median ages of the children critically ill with H1N1 was 6 years. Most had respiratory failure, sixty-six per cent required mechanical ventilation, plus some required extracorporeal membrane oxygenation (ECMO) for advanced cardiac and respiratory support. Their disease progressed rapidly, and 75 children (9 percent) died, sixty-six per cent of them within 14 days of ICU admission.
“Some children were quickly overwhelmed, and lots of died despite centers doing everything just to save them,” says Randolph. “At the start of the pandemic, centers were worried that they can would run out of ventilators, they would uses up ICU beds.”
Many with the children critically ill with H1N1 had more than one chronic medical ailments that increased their risk, including asthma, neurologic disorders or compromised immune systems, 251 children (30 percent) were previously healthy.
Among these otherwise healthy children, the only real risk component that was identified for death from influenza would be a presumed proper diagnosis of MRSA co-infection in the lung – which increased danger for mortality 8-fold (P<0.0001).
“It’s not at all common inside the U.S. to get rid of a previously healthy child to pneumonia,” says Randolph. “Unfortunately, these children had necrotizing pneumonia – wearing at their tissue and killing off whole regions of the lung. They appeared to be immunocompromised patients in terms MRSA went through themselves. It is not that flu alone can’t kill – it could possibly – however in many instances kids with flu alone survived.”