Oct. 29, 2009 (Philadelphia) -- Some elementary school kids with the swine flu are still shedding H1N1 virus six days after their fever strikes, a new study suggests.
Researchers stopped short of saying these youngsters could still transmit the virus to their friends and family.
But the findings raise a red flag, reinforcing the importance of getting school-aged kids vaccinated, doctors say.
Achuyt Bhattarai, MD, of the CDC, and colleagues looked at shedding patterns of the H1N1 virus during an outbreak at an elementary school in Pennsylvania in May and June.
The researchers swabbed the noses and throats of 13 elementary school kids, ages 5 to 9, who had a fever of 100 degrees or higher and a cough and/or sore throat. Samples were also obtained from 13 of their flu-stricken family members.
"Overall, we found the median duration of shedding to be six days, with a minimum of one day and a maximum of 13 days," Bhattarai says.
The elementary school kids also shed H1N1 virus for a median of six days after their fever struck, he tells WebMD.
The findings were presented at the annual meeting of the Infectious Diseases Society of America (IDSA).
These and future findings will help health officials decide when children should go back to school, says the University of Utah's Andrew Pavia, MD, head of the IDSA's pandemic influenza task force.
The CDC recommends that children with flu-like symptoms stay home and not return to school until at least 24 hours after they are free of a fever of 100 degrees or more without using fever-reducing medicines.
"While someone who has been without fever for 24 hours without use of fever-reducing medicine can in fact shed virus, we don't believe they shed enough virus to make others sick," says Thomas Skinner, a CDC spokesman. "It's possible but not likely."
Pavia notes that the swine flu appears to act quite differently than the seasonal flu. Young people with swine flu tend to get sicker than older adults, the opposite of what happens with seasonal flu.
The bottom line: make sure your children get the H1N1 vaccination, which is very safe, says Bruce Gellin, MD, MPH, director of the HHS National Vaccine Program Office.
"This is clearly a novel virus, but it's not a new vaccine. The swine flu vaccine is made exactly the same way as the seasonal flu vaccine" and there are no differences in terms of safety, he tells WebMD.