H1N1 Swine Flu Wave Peaking in U.S.?

New Cases Decline but Deaths, Hospitalizations Still Rising

Medically Reviewed by Louise Chang, MD on November 20, 2009
From the WebMD Archives

Nov. 20, 2009 - The current wave of the H1N1 swine flu pandemic may have peaked in the U.S., new CDC figures suggest.

A lot of people are still coming down with H1N1 swine flu. New cases -- as measured by the number of health care visits by people with flu symptoms -- remain epidemic in every part of the country. Flu is still widespread in 43 states, but that's down from 46 states last week and from 48 states the week before that.

And for the first time, new flu cases are trending downward in all parts of the country, although this downward trend only appeared this week in New England and New Jersey/New York.

Moreover, Quest Diagnostics, a lab that since May has tested more than 142,000 patient samples for H1N1 swine flu virus, reports that requests for H1N1 tests have been declining since Oct. 28 -- about the time flu-like illnesses started declining in some parts of the U.S.

This doesn't mean there's not more bad news to come. Deaths and hospitalizations peak weeks after new cases peak. A grim reminder: In the last week there were 21 new deaths among children and teens, bringing the official total for the pandemic to 171 kids. And these lab-confirmed cases are just a partial count, noted Anne Schuchat, MD, CDC director of immunization and respiratory diseases, at today's weekly news briefing.

"I wish I knew if we had hit the peak," Schuchat said. "What I can say is that even when a peak has occurred, half of the people who are going to become ill haven't gotten ill yet."

Schuchat noted that even if this wave of the flu pandemic is peaking, there's no way to know whether new cases will continue to decline, whether they'll go up and down for a while, or whether they'll climb again later this flu season.

"Influenza season goes from December to May. ... We may have weeks and months of a lot of disease ahead of us," she said. "And as families gather over the holiday, we might see an increase in influenza or other infectious disease activities. ... There's a lot of exchange of warmth and love, but a little exchange of viruses, too."

To blunt this trend, the CDC is urging people to stay away from family gatherings if they aren't feeling well. And that goes for children, too.

What else can people do? Get vaccinated with both the 2009 H1N1 and the seasonal flu vaccines.

Schuchat noted that in the last week, 11 million more doses of H1N1 swine flu vaccine became available to states. That brings the total number of doses to 54.1 million -- not as many as had been predicted, but enough to start meeting demand in some areas.

And 94.5 million of an expected 114 million doses of seasonal flu vaccine have been delivered to providers. Right now, this vaccine remains available in most areas of the nation.

Show Sources


CDC news conference with Anne Schuchat, MD, director, National Center for Immunization and Respiratory Diseases.

Quest Diagnostics Health Trend Report, Nov. 20, 2009.

FluView, CDC web site.

© 2009 WebMD, LLC. All rights reserved. View privacy policy and trust info