TUESDAY, Nov. 1, 2005 (HealthDay News) -- While U.S. health officials already recommend that a number of children with chronic diseases, such as diabetes, heart disease and lung disorders, be vaccinated for influenza, a new study finds another group of children should be added to that list -- those with neurological or neuromuscular diseases.
The reason, according to the study from the Children's Hospital of Philadelphia and the U.S. Centers for Disease Control and Prevention, is that these children face a higher risk of serious flu-related complications. In fact, the study found that children with neurological or neuromuscular diseases (NNMD) are at a six-fold greater risk of flu-related respiratory failure.
"Three conditions were most associated with respiratory failure in children admitted with lab-confirmed influenza: lung diseases other than asthma, cardiac disease and neurological and neuromuscular disorders," said the study's lead author, Dr. Ron Keren, an attending physician in general pediatrics at the Children's Hospital.
Results of the study appear in the Nov. 2 issue of the Journal of the American Medical Association.
Neurological and neuromuscular diseases include disorders such as cerebral palsy, hydrocephalus, muscular dystrophy and seizure disorders.
The lung diseases include cystic fibrosis and chronic lung disease from prematurity; the heart diseases include congenital heart disease, arrhythmias, and any other anatomical or functional heart defect, according to Keren.
Every year between one in five and one in 20 Americans comes down with the flu, depending on the severity of the strains circulating. On average, about 36,000 people die each year in the United States from flu-related complications, according to the CDC.
While children with heart disease and lung disease were already on the CDC's list of people at high-risk from the flu, researchers with the CDC noticed an increased rate of death from flu complications in several other groups of children, including those with NNMD, gastroesophageal reflux disease (GERD) and those with a history of prematurity, according to Keren.
To assess the risks from those disorders, as well as those already identified as high-risk, Keren and his colleagues collected data for four years and identified 745 children with lab-confirmed influenza who were eligible for the study.
Of those children, 322 had at least one chronic medical condition. The most common was asthma -- 24 percent had a history of the disease. Three percent of the children had a history of prematurity, while 12 percent had NNMD and 14 percent had a history of GERD.
Thirty-two children developed respiratory failure, which meant they had to be placed on a ventilator to help them breathe.
The researchers found that children with NNMD were most likely to develop respiratory failure. They were also at a six-fold higher risk of respiratory failure. Children with lung diseases other than asthma faced a nearly five-fold increased risk, while those with cardiac disease were at a four-fold higher risk than children without this condition.
"The NNMD result was surprising given the focus on other conditions," said Keren. But, he added, "It wasn't really surprising because children with NNMD often have weak muscles of respiration and have difficulty handling secretions."
Using statistical modeling, the researchers found that a child with NNMD who gets the flu is at a 10 percent risk of developing respiratory failure.
In response to these results, Keren said the CDC presented these findings to its Advisory Committee on Immunization Practices (ACIP). The ACIP decided to add NNMD to the list of chronic conditions that place a child in the high-risk category.
The bottom line? "If your child has a chronic health condition, you need to go to the doctor and get your child the flu vaccine every year," said Keren.
And, don't forget your own shot, too, said Dr. Graham Krasan, an infectious disease specialist at Beaumont Hospital in Royal Oak, Mich., who added that message is often lost.
"Even when the at-risk children are immunized, they may still be vulnerable to influenza," he said. "A better containment strategy may be to immunize all of those around the children as well."
Both Keren and Krasan said the next step may be to see if giving antiviral agents early in the course of influenza can help prevent respiratory failure in children with NNMD.
For more on flu vaccine, visit the U.S. Centers for Disease Control and Prevention.