People With Swine Flu May Be Contagious Longer Than Thought

Sept. 15 -- TUESDAY, Sept. 15 (HealthDay News) -- People infected with swine flu seem to be contagious longer than patients with ordinary seasonal flu, several new studies suggest.

But it's not clear what impact the findings will have on health-care experts' recommendations to combat the H1N1 swine flu, since the virus continues to produce relatively mild infections in most people and recovery time is fairly fast, just like seasonal flu, the Associated Press reported.

"This study shows you're not contagious for a day or two" with H1N1 swine flu. "You're probably contagious for about a week," said Gaston De Serres, a scientist at the Institute of Public Health in Quebec, Canada, who presented one of the studies Monday at an American Society for Microbiology conference in San Francisco.

Levels of virus present in nasal mucus can give experts an indication of whether the flu can still be spread by coughing and sneezing. In the Canadian study, between 19 percent to 75 percent of people with H1N1 flu still showed signs of virus in their noses eight days after the first onset of symptoms. Two others studies -- one from Singapore, the other from Mexico -- produced similar results.

The meeting is the first major gathering of infectious-disease experts since swine flu first emerged last spring in Mexico and the United States, before circulating around much of the globe. The World Health Organization is currently reporting nearly 280,000 cases of infection, with at least 3,205 deaths worldwide.

In the United States, H1N1 swine flu now accounts for an estimated 98 percent of the flu virus in circulation, with more than 1 million cases of infection and an estimated 600 deaths. By way of comparison, regular seasonal flu hospitalizes more than 200,000 American each year and causes an estimated 36,000 deaths, according to the U.S. Centers for Disease Control and Prevention.

The CDC has been recommending that people infected with swine flu stay home and avoid contact with others for at least one day after they've been free of fever without the use of fever-reducing medications.