A dramatic increase in the number of U.S. children who died last year from influenza --- while also battling staph infections --- has the Centers for Disease Control and Prevention warning doctors to be on the alert as the nation enters the worst part of the winter flu season.
Georgia health officials, who also recorded a local spike in child flu deaths associated with staph infections last year, urged parents to make sure their children are properly vaccinated.
The CDC is calling on doctors to promptly report all flu deaths among children and send in samples from any who also were infected with the bacteria Staphylococcus aureus. The Atlanta-based agency is investigating whether some staph strains circulating in the community have developed increased virulence, or ability to cause disease.
So far this flu season, which began Oct. 1, the CDC has received only one report of a pediatric flu death. But during the 2006-2007 flu season, the agency got reports of 73 children dying from influenza --- a number they described as "moderately higher" than the 47 and 46 who died in each of the previous two flu seasons.
The number of flu deaths last year associated with staph infections was five times greater than in those previous years, the CDC said in a national alert sent to health departments and medical groups Wednesday night.
At least 22 of the U.S. children who died of flu last year also had a staph infection. Fifteen of them had a drug-resistant strain called MRSA, the alert said.
In Georgia, the deaths of six children were attributed to flu last year. Four also had staph infections, all but one of them involving MRSA, said Ariane Reeves, influenza surveillance coordinator for the Georgia Division of Public Health.
MRSA, which stands for methicillin-resistant Staphylococcus aureus, usually causes skin infections, such as pimples and boils. But it also can cause pneumonia and blood infections.
While most serious staph and MRSA infections involve people who have been hospitalized, they are increasingly occurring in people out in the general community.
Pediatric infectious disease experts said that, over the past five years, they've been seeing an increased number of staph pneumonia cases in children with flu.
"When I was trained as a doctor and an infectious disease specialist, we basically never saw staph pneumonia. ... Now we see staph pneumonia all the time," said Dr. Jonathan McCullers, a researcher who studies the interaction between influenza and bacteria like staph at St. Jude Children's Research Hospital in Memphis.
Historically, staph pneumonia tended to occur in people only when the worst strains of flu were circulating, such as during the 1918 and 1957 pandemics, McCullers said.
In recent years, the flu virus strains have been less severe --- but the staph bacteria appears to be adapting, he said. "The bacteria seems to be changing and is now better suited to work with the virus," McCullers said.
Exactly how they may be working together to produce severe disease is not known, McCullers said.
Minor staph infections are common. The CDC estimates that 25 to 30 percent of people have staph bacteria in their noses, and 1 percent carry MRSA, though they have no signs of illness or infection. When staph does cause infections, they usually are minor skin problems.
While child deaths from flu are rare, the CDC estimates that 20,000 children each year are hospitalized because of flu-related complications.
Dr. Harry Keyserling, a pediatrics professor at Emory University School of Medicine in Atlanta, said the most important thing parents can do is vaccinate their children against flu.
The CDC recommends vaccinations for children ages 6 months to 5 years old. Keyserling said parents should call a doctor if their child has difficulty breathing, turns blue or is not as alert as usual.
At the CDC, scientists have more questions than answers, which is why they've asked doctors to send in samples of staph bacteria involved in childhood flu deaths this winter.
"We are not sure why we've had such an increase in Staph aureus," CDC epidemiologist Lyn Finelli said Thursday. But the agency's recent analysis of last season's childhood flu deaths was cause for concern.
The flu strains infecting the dead children last year were not different from the strains circulating in the community, the CDC said in its alert. And the MRSA strains involved in the deaths have been similar to those involved in common skin infection outbreaks, the agency said.
The alert notes that the children who died when infected with both flu and staph were older, a median age of 10, than those who just had flu. The median age of those who had only flu was 5.
"We're not exactly sure why that is," Finelli said. It could be because school-aged children are more likely to be colonized with staph and MRSA than younger children, she said.
Children who die from flu tend to die quickly regardless of whether they also have a staph infection, Finelli said. Just four days is the median time between when children have symptoms and when they die. About 40 to 50 percent of the children who die from flu die at home or in the emergency room, she said, illustrating how quickly the disease can go from routine to deadly.
The CDC is advising doctors to test people with serious respiratory illnesses for influenza, including those who are suspected of having pneumonia. It also is alerting doctors to be aware of the possibility that children who have the influenza virus also may have a bacterial infection, and to keep in mind the prevalence of MRSA infections when choosing an antibiotic to make sure it's one that will work.
While the CDC has tracked childhood flu deaths since 2004, it doesn't track adult flu deaths. So it's unclear whether there has been any similar increase in adults dying from flu-staph infections, she said. But the agency has investigated some individual adult cases of flu-associated MRSA pneumonia, including some in Georgia and Louisiana in 2006-2007.
ADVICE TO PARENTS
While flu deaths among children are rare, the CDC estimates that 20,000 children younger than 5 are hospitalized each year with serious flu-related complications. Here's what you can do to protect your children:
> Vaccinate: Influenza is preventable, and the CDC recommends vaccinating most children. Although it's best to get vaccinated in the fall before flu is prevalent, it's still not too late to get protected, CDC officials said. Parents concerned about the preservative Thimerosal can request a mercury-free form of the vaccine.
CDC recommends vaccination of healthy children who are 6 months to 5 years old. The vaccine is approved by the Food and Drug Administration for use in older children. The CDC recommends it for children and adolescents at high risk of flu because they have medical conditions such as asthma or other chronic pulmonary diseases, immune disorders, diabetes and sickle-cell anemia.
> Wash hands: Good hand hygiene goes a long way toward preventing the spread of both flu and staph. Help children remember to wash their hands often with soap and water. Skin infections caused by staph should be kept clean and covered, and parents should watch for signs of further infection.
> Consult with your pediatrician: Because young children are at risk of complications from the flu, check with their doctor to see if a checkup is warranted by a fever, loss of appetite and reduction in their activity level.
> Get tested: If your child has a severe respiratory illness, talk with doctors about testing for both influenza and bacterial infections. If the child has flu, the doctor may want to consider prescribing an antiviral drug. An antibiotic may be needed if the child also has a staph infection.
Sources: CDC, Georgia Division of Public Health
Copyright 2008 The Atlanta Journal-Constitution