CDC Issues Guidelines on Antiviral Use for Influenza

Children younger than 1 year of age may be given oseltamivir for influenza treatment and prophylaxis despite the expiration of the Food and Drug Administration’s emergency authorization allowing use of the drug in that age group. The Centers for Disease Control and Prevention issued new guidelines Jan. 21.

In an interview, the CDC’s Dr. Tim Uyeki said, "ACIP [the Advisory Committee on Immunization Practices] and CDC are recommending use of oseltamivir for treatment or chemoprophylaxis in children less than 1 year of age with suspected or confirmed influenza, because of the high risk for complications – including serious complications – in children less than 1 year of age, as well as the fact that the 2009 H1N1 virus continues to circulate worldwide including in the U.S."

The FDA issued its emergency use authorization during the 2009-2010 pandemic of influenza A(H1N1). The authorization expired in June 2010.

While encouraging the use of the neuraminidase inhibitors oseltamivir (Tamiflu) and zanamivir (Relenza), the new guidelines emphasize that the antivirals amantadine (Symmetrel) and rimantadine (Flumadine) should not be used for influenza. Those drugs are inactive against influenza B, and the currently circulating strains of influenza A have developed resistance.

In another significant change, the guidelines now emphasize that it’s permissible to treat individuals with influenza who are at low risk of complications with oseltamivir and zanamivir.

"We never said, ‘Don’t treat persons who are not hospitalized and not high risk,’ " said Dr. Uyeki, a pediatrician and medical epidemiologist. "The emphasis on high-risk patients and hospitalized patients might have been interpreted as, ‘Don’t treat persons with mild, uncomplicated illness who were previously healthy.’ "

The guidelines encourage physicians to rely on their clinical judgment in making treatment decisions regarding patients with suspected or confirmed influenza. Knowledge of the locally prevalent influenza strains as well as local patterns of antiviral resistance should inform that judgment.

In other influenza news:

• The CDC reports in its latest update that eight children have died from influenza in the United States so far this season. In comparison, there were 282 pediatric deaths during the full 2009-2010 season and 133 during the 2008-2009 season. The CDC continues to find no evidence of resistance to oseltamivir and zanamivir by any influenza strain currently circulating. In the week ending Jan. 8, 2010, 11 states were reporting widespread influenza activity (Alabama, Arizona, Connecticut, Kentucky, Louisiana, Maryland, Nevada, New York, North Carolina, Tennessee, and Virginia). Another 17 states were reporting regional influenza activity (Colorado, Florida, Georgia, Illinois, Indiana, Kansas, Maine, Massachusetts, Mississippi, Missouri, New Hampshire, New Jersey, Ohio, Oklahoma, Pennsylvania, South Carolina, and Texas). The remaining states were reporting only local or sporadic influenza activity.

• In its latest influenza update, the World Health Organization reports that influenza cases are continuing to increase in North America, and that the primary strain is influenza A(H3N2). In the United Kingdom, severe and fatal cases of influenza A(H1N1) have increased compared with 2 weeks ago, and 25% of all intensive care beds are occupied by influenza patients. Severe disease associated with influenza A(H1N1) and, to a lesser extent, influenza B are also increasing throughout the European continent and the Middle East. On the other hand, tropical countries throughout the world and temperate countries in the Southern Hemisphere are reporting very little influenza circulation.

Children younger than 1 year of age may be given oseltamivir for influenza treatment and prophylaxis despite the expiration of the Food and Drug Administration’s emergency authorization allowing use of the drug in that age group. The Centers for Disease Control and Prevention issued new guidelines Jan. 21.

In an interview, the CDC’s Dr. Tim Uyeki said, "ACIP [the Advisory Committee on Immunization Practices] and CDC are recommending use of oseltamivir for treatment or chemoprophylaxis in children less than 1 year of age with suspected or confirmed influenza, because of the high risk for complications – including serious complications – in children less than 1 year of age, as well as the fact that the 2009 H1N1 virus continues to circulate worldwide including in the U.S."

The FDA issued its emergency use authorization during the 2009-2010 pandemic of influenza A(H1N1). The authorization expired in June 2010.

While encouraging the use of the neuraminidase inhibitors oseltamivir (Tamiflu) and zanamivir (Relenza), the new guidelines emphasize that the antivirals amantadine (Symmetrel) and rimantadine (Flumadine) should not be used for influenza. Those drugs are inactive against influenza B, and the currently circulating strains of influenza A have developed resistance.

In another significant change, the guidelines now emphasize that it’s permissible to treat individuals with influenza who are at low risk of complications with oseltamivir and zanamivir.

"We never said, ‘Don’t treat persons who are not hospitalized and not high risk,’ " said Dr. Uyeki, a pediatrician and medical epidemiologist. "The emphasis on high-risk patients and hospitalized patients might have been interpreted as, ‘Don’t treat persons with mild, uncomplicated illness who were previously healthy.’ "

The guidelines encourage physicians to rely on their clinical judgment in making treatment decisions regarding patients with suspected or confirmed influenza. Knowledge of the locally prevalent influenza strains as well as local patterns of antiviral resistance should inform that judgment.

In other influenza news:

• The CDC reports in its latest update that eight children have died from influenza in the United States so far this season. In comparison, there were 282 pediatric deaths during the full 2009-2010 season and 133 during the 2008-2009 season. The CDC continues to find no evidence of resistance to oseltamivir and zanamivir by any influenza strain currently circulating. In the week ending Jan. 8, 2010, 11 states were reporting widespread influenza activity (Alabama, Arizona, Connecticut, Kentucky, Louisiana, Maryland, Nevada, New York, North Carolina, Tennessee, and Virginia). Another 17 states were reporting regional influenza activity (Colorado, Florida, Georgia, Illinois, Indiana, Kansas, Maine, Massachusetts, Mississippi, Missouri, New Hampshire, New Jersey, Ohio, Oklahoma, Pennsylvania, South Carolina, and Texas). The remaining states were reporting only local or sporadic influenza activity.

• In its latest influenza update, the World Health Organization reports that influenza cases are continuing to increase in North America, and that the primary strain is influenza A(H3N2). In the United Kingdom, severe and fatal cases of influenza A(H1N1) have increased compared with 2 weeks ago, and 25% of all intensive care beds are occupied by influenza patients. Severe disease associated with influenza A(H1N1) and, to a lesser extent, influenza B are also increasing throughout the European continent and the Middle East. On the other hand, tropical countries throughout the world and temperate countries in the Southern Hemisphere are reporting very little influenza circulation.

Children younger than 1 year of age may be given oseltamivir for influenza treatment and prophylaxis despite the expiration of the Food and Drug Administration’s emergency authorization allowing use of the drug in that age group. The Centers for Disease Control and Prevention issued new guidelines Jan. 21.

In an interview, the CDC’s Dr. Tim Uyeki said, "ACIP [the Advisory Committee on Immunization Practices] and CDC are recommending use of oseltamivir for treatment or chemoprophylaxis in children less than 1 year of age with suspected or confirmed influenza, because of the high risk for complications – including serious complications – in children less than 1 year of age, as well as the fact that the 2009 H1N1 virus continues to circulate worldwide including in the U.S."

The FDA issued its emergency use authorization during the 2009-2010 pandemic of influenza A(H1N1). The authorization expired in June 2010.

While encouraging the use of the neuraminidase inhibitors oseltamivir (Tamiflu) and zanamivir (Relenza), the new guidelines emphasize that the antivirals amantadine (Symmetrel) and rimantadine (Flumadine) should not be used for influenza. Those drugs are inactive against influenza B, and the currently circulating strains of influenza A have developed resistance.

In another significant change, the guidelines now emphasize that it’s permissible to treat individuals with influenza who are at low risk of complications with oseltamivir and zanamivir.

"We never said, ‘Don’t treat persons who are not hospitalized and not high risk,’ " said Dr. Uyeki, a pediatrician and medical epidemiologist. "The emphasis on high-risk patients and hospitalized patients might have been interpreted as, ‘Don’t treat persons with mild, uncomplicated illness who were previously healthy.’ "

The guidelines encourage physicians to rely on their clinical judgment in making treatment decisions regarding patients with suspected or confirmed influenza. Knowledge of the locally prevalent influenza strains as well as local patterns of antiviral resistance should inform that judgment.

In other influenza news:

• The CDC reports in its latest update that eight children have died from influenza in the United States so far this season. In comparison, there were 282 pediatric deaths during the full 2009-2010 season and 133 during the 2008-2009 season. The CDC continues to find no evidence of resistance to oseltamivir and zanamivir by any influenza strain currently circulating. In the week ending Jan. 8, 2010, 11 states were reporting widespread influenza activity (Alabama, Arizona, Connecticut, Kentucky, Louisiana, Maryland, Nevada, New York, North Carolina, Tennessee, and Virginia). Another 17 states were reporting regional influenza activity (Colorado, Florida, Georgia, Illinois, Indiana, Kansas, Maine, Massachusetts, Mississippi, Missouri, New Hampshire, New Jersey, Ohio, Oklahoma, Pennsylvania, South Carolina, and Texas). The remaining states were reporting only local or sporadic influenza activity.

• In its latest influenza update, the World Health Organization reports that influenza cases are continuing to increase in North America, and that the primary strain is influenza A(H3N2). In the United Kingdom, severe and fatal cases of influenza A(H1N1) have increased compared with 2 weeks ago, and 25% of all intensive care beds are occupied by influenza patients. Severe disease associated with influenza A(H1N1) and, to a lesser extent, influenza B are also increasing throughout the European continent and the Middle East. On the other hand, tropical countries throughout the world and temperate countries in the Southern Hemisphere are reporting very little influenza circulation.