H1NI Influenza Outbreak

CDC Updates Antiviral Guidance

By News Staff
Posted: 5/13/2009, 10:45 a.m.

Acknowledging that the novel influenza A (H1N1) virus is not as virulent as health officials feared initially, the CDC has updated its guidance on the use of antiviral medications to treat and prevent H1N1 infections.

Anne Schuchat, M.D., interim deputy director for the CDC's Science and Public Health Program, said in a May 9 press briefing that the vast majority of Americans infected with the virus have had self-limited respiratory illness.

The agency reported on its Web site that the benefits of using antiviral drugs may be modest for patients who are not in high-risk groups and recommended that testing, treatment and chemoprophylaxis efforts be directed primarily at persons who are hospitalized or at higher risk for influenza complications.

"We're really trying to make sure that the antiviral therapy is available for those in a high-risk group," said Schuchat.

Specifics of Antiviral Drug Use

Taking into account the FDA's recent announcement regarding Emergency Use Authorizations for antiviral medications, the CDC is recommending treatment with either oseltamivir or zanamivir for all hospitalized patients with confirmed, probable or suspected novel influenza A H1N1 infection, as well as for the following groups at high risk for flu-related complications:

children younger than age 5 years;
adults 65 and older;
people with chronic pulmonary (including asthma), cardiovascular (except hypertension), renal, hepatic, hematological (including sickle cell disease), neurologic, neuromuscular, or metabolic (including diabetes mellitus) disorders;
people with immunosuppression, including that caused by medications or HIV infection;
pregnant women;
people younger than 19 who are receiving long-term aspirin therapy; and
residents of nursing homes and other chronic-care facilities.

Swine Flu Info

The CDC said that if a patient is not in a high-risk group or is not hospitalized, physicians should rely on their clinical judgment to make treatment decisions. Agency officials also said that when evaluating children, health care professionals should be aware that the risk for severe complications from influenza in children is highest among those younger than 2 years old.

For chemoprophylaxis against the infection, the CDC recommends physicians consider using antiviral drugs in the following groups:

people who are at high risk for serious seasonal flu-related complications and have been in close contact with someone who is ill with novel H1N1 viral infection; and
health care workers, public health workers and emergency responders who have been in close, unprotected contact with someone who is sick with novel H1N1 infection.

CDC officials recommend that health care workers, public health workers and emergency responders use appropriate personal protective equipment during exposure to people who are infected with novel H1N1 virus. The agency also said that pregnant health care workers whose jobs bring them into close contact with people who may have H1N1 infection should consider seeking temporary reassignment to a position that does not involve direct patient contact.

New CDC Data Collection Forms Available

CDC has issued data collection forms for cases involving patients infected with novel influenza A (H1N1). The agency is asking public health officials, researchers and clinicians to collect information about these patients to help characterize the disease spectrum and severity, understand what factors may increase the risk for severe disease, and guide health care decisions and resource allocation.

The forms allow health care professionals to make basic and more detailed case reports of H1N1 infections, including cases involving health care workers and pregnant women. Specialized data collection forms for people in contact with infected patients and those who have been hospitalized with H1N1 infection also are provided.

Completed forms can be e-mailed or faxed to the CDC at (404) 248-4094.

U.S. Case Numbers "Still in the Upswing"

As of May 11, the CDC said there were 3,009 laboratory-confirmed human infections with novel H1N1 flu in 44 states and Washington, D.C., and 643 probable cases nationwide. One hundred and sixteen patients have been hospitalized with the infection, and the third U.S. death attributed to the virus was reported May 9 in Washington state.

Richard Besser, M.D., acting director of the CDC, said during a May 7 press briefing that although the virus appears to be similar to seasonal flu in terms of severity, people should remain vigilant about hand washing, covering their coughs and sneezes and staying home from work or school if they are ill. The nation still is in the upswing of an epidemic curve and more cases and deaths are expected, he noted.

Besser said the CDC is studying numerous aspects of the outbreak, including evaluation of rapid diagnostic tests, duration of virus shedding in various age groups and transmission among health care workers. The study of health care workers could lead to updated guidance, he said.

Where to Go to Learn More

In other news, the CDC announced that it plans to continue its weekly FluView reports -- which typically end in May -- into the summer. This online resource reports where influenza activity is occurring, identifies what flu viruses are circulating, shares information on known changes in flu viruses and tracks numbers of flu-related deaths.

On May 11, CDC updated its interim guidance documents on the following H1N1-related topics:

The agency also recently updated its guidance on public gatherings.