Study Finds H1N1 Virus Lives Longer Than Expected When more than 100 students at the U.S. Air Force Academy were diagnosed with swine flu, doctors had an opportunity to study the virus closely. They discovered that some cadets who had been symptom-free for more than 24 hours still had the live virus in their noses.
NPR logo

Study Finds H1N1 Virus Lives Longer Than Expected

  • Download
  • <iframe src="" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript
Study Finds H1N1 Virus Lives Longer Than Expected

Study Finds H1N1 Virus Lives Longer Than Expected

  • Download
  • <iframe src="" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript


This is MORNING EDITION from NPR News. Good morning. I'm Renee Montagne


And I'm Steve Inskeep.

I came home this week to news that somebody caught swine flu at my daughter's school. Families in many communities have heard similar news, and in this part of the program, we're going to ask about swine flu vaccine and kids. We start with some questions about what to do if you get the disease. The current public health recommendation is that you can return to school or work 24 hours after your fever goes away. Now, a study says 24 hours may not always be long enough.

NPR's Joanne Silberner reports.

JOANNE SILBERNER: The finding comes from some very alert scientists. Last summer, Catherine Takacs Witkop and her medical colleagues at the U.S. Air Force Academy in Colorado were presented with an opportunity. Fourteen hundred new cadets had arrived at the academy. Between June 26th and July 4th, there were few cases of flu-like illnesses. After a party in early July, the numbers skyrocketed as cadets came down with fevers, cough, fatigue and other symptoms. It was all very clear to Witkop.

Dr. CATHERINE TAKACS WITKOP (U.S. Air Force Academy): Within approximately 10 days of their arrival, we saw an increase in respiratory illness among our cadets, and what we learned within a very short period of time was that this was a novel H1N1 outbreak.

SILBERNER: A total of 134 cases of swine flu and 33 suspected cases — 11 percent of the cadets. The Air Force Academy set up an isolation ward: two floors of a dorm. They wanted to know how soon they could send the cadets back to basic training. The government's advice: People can return their normal activities after 24 hours of no fever. But the Air Force Academy doctors realized no one really knew for the H1N1 flu. They got the cadets to agree to nasal washes — a squirt of saline in their noses - and looked for any viruses that came out.

Dr. WITKOP: Nineteen percent of those samples from cadets who were more than 24 hours symptom-free actually contained live virus.

SILBERNER: Witkop, of the Air Force Academy, says the findings suggest people who are going to be in high-risk settings - hospitals, day care centers or around pregnant women - should stay home longer or keep their distance.

At the CDC, Dr. Anne Schuchat says she's not surprised that the study, reported in the American Journal of Preventive Medicine, described some of the cadets as still shedding virus after they were well.

Rear Admiral ANNE SCHUCHAT (Deputy Director, Science and Health Program, CDC): What's important to say is that shedding doesn't mean you're spreading.

SILBERNER: And she said the advice remains the same.

Rear Admiral SCHUCHAT: People should stay home for 24 hours after their fever is gone without taking anti-fever medicines. And that really is a balance of making sure that most of the transmission is prevented, and yet we're balancing how long and how disruptive our interventions are.

SILBERNER: You can't isolate people for days after they're well, says Dr. William Schaffner, head of preventive medicine at Vanderbilt University.

Dr. WILLIAM SCHAFFNER (Preventive Medicine, Vanderbilt University): It's not possible to have a plan that's completely safe. We're trying to do what's best but also be practical.

SILBERNER: People are most infectious in their first couple of days of illness and a day before symptoms appear, he says. A completely safe policy would mean isolating everyone. Schaffner says the finding is a reminder about personal hygiene — that healthy people, people who've been sick, and people who might get sick should wash their hands frequently. And when the urge to cough hits, do so into your elbow. And he's got one more piece of advice.

Dr. SCHAFFNER: The best way to avoid all this is to get vaccinated just as quickly as possible.

SILBERNER: Following that advice could take some time. At the moment, the vaccine is mostly in limited distribution, available primarily to at-risk groups such as health care workers, pregnant women, people with chronic health conditions and kids.

Joanne Silberner, NPR News.

Copyright © 2009 NPR. All rights reserved. Visit our website terms of use and permissions pages at for further information.

NPR transcripts are created on a rush deadline by Verb8tm, Inc., an NPR contractor, and produced using a proprietary transcription process developed with NPR. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.