Children with neurological and neuromuscular diseases at risk for flu-related re

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Children with neurological and neuromuscular diseases at risk for flu-

related respiratory failure

http://www.medicalnewstoday.com/medicalnews.php?newsid=33017

Children with neurological and neuromuscular diseases should receive

an annual influenza vaccination because of a higher risk of

respiratory failure if they are hospitalized with influenza,

according to a study in the November 2 issue of JAMA.

Influenza is a common disease of childhood and is responsible for

significant illness, according to background information in the

article. Healthy young children are hospitalized for influenza-

related illness at rates similar to those for elderly persons and

adults with chronic medical conditions. Perhaps most concerning to

parents and physicians is the potential for serious influenza-

associated complications, including carditis (inflammation of the

heart), encephalitis, myositis (inflammation of muscle tissue),

pneumonia, respiratory failure, and death.

Population-based studies suggest that individuals with certain

chronic medical conditions are at increased risk of serious

complications of influenza infection. The Advisory Committee on

Immunization Practices (ACIP) has identified 9 groups of chronic

medical conditions for which annual influenza vaccination is

recommended. They include asthma, chronic lung disease, cardiac

disease, immunosuppression, hemoglobinopathies (a blood disease

characterized by the presence of abnormal hemoglobins in the blood),

chronic renal dysfunction, metabolic and endocrine conditions, long-

term salicylate (aspirin and some other drugs) therapy, and

pregnancy. Despite the frequency of influenza infection and the

prevalence of these chronic medical conditions, little is known about

their relative contribution to the development of serious influenza-

associated complications.

Ron Keren, M.D., M.P.H., of The Children's Hospital of Philadelphia,

and colleagues conducted a study to identify chronic medical

conditions that were associated with respiratory failure in children

hospitalized with influenza. In addition to the current ACIP-

designated high-risk conditions, the researchers also examined three

other categories of chronic medical conditions--neurological and

neuromuscular disease (NNMD, such as muscular dystrophy),

gastroesophageal reflux disease (GERD), and history of prematurity,

that in recent studies have been associated with influenza

hospitalization and severe influenza-related complications. The study

included patients aged 21 years or younger hospitalized at The

Children's Hospital of Philadelphia, with community-acquired

laboratory-confirmed influenza during 4 consecutive influenza seasons

(June 2000 through May 2004).

Of 745 children hospitalized with influenza, 322 (43 percent) had one

or more ACIP-designated high-risk chronic medical conditions. NNMD,

GERD, and history of prematurity were present in 12 percent, 14

percent, and 3 percent, of children, respectively. Thirty-two

children (4.3 percent) developed respiratory failure. In further

analyses, conditions associated with respiratory failure included

NNMD (6 times increased risk), chronic pulmonary disease other than

asthma (4.8 times increased risk), and cardiac disease (4 times

increased risk). The predicted probabilities of respiratory failure

derived from the multivariate model were 12 percent, 9 percent, and 8

percent for children with NNMD, chronic pulmonary disease, and

cardiac disease, respectively. Children hospitalized with influenza

who had 2 of these 3 chronic conditions had a 31 percent to 39

percent predicted probability of respiratory failure.

" The significantly increased probability of respiratory failure in

children with NNMD hospitalized with influenza supports the ACIP's

recent decision to add NNMD that may compromise respiratory function

to the list of chronic conditions that warrant annual influenza

vaccination. Coordinated efforts are needed to educate parents,

primary care pediatricians, and pediatric neurologists about the

risks of serious influenza complications and the need for annual

vaccination for children with NNMD. Future studies should determine

the risk of hospitalization among children with NNMD, the number of

additional children with NNMD who will require annual vaccination, as

well as the effectiveness and cost-effectiveness of the influenza

vaccine in preventing hospitalizations and serious complications in

these children, " the authors conclude.

(JAMA.2005; 294:2188-2194)

This work was supported by a grant from the Centers for Disease

Control and Prevention (CDC). Dr. Keren was supported by a grant from

the National Institute of Child Health and Human Development,

Bethesda, Md.