Flu transmitted before symptoms appear: Study
Flu virus can be transmitted even before the appearance of their symptoms as experiments with ferrets (European polecat) have shown, according to a study.
If applied to human, it suggests that people pass on flu to others before they know they are infected, making it very difficult to contain epidemics.
Knowing if people are infectious before they have symptoms is important to help authorities plan for an epidemic, but it has been difficult to establish this from data collected during outbreaks, the journal Public Library of Science ONE reports.