The common belief about the flu spread has now been challenged by the discovery. Flu can now be transmitted just by breathing, finds a new study.
- Influenza virus (flu) in contrast with what was commonly thought to only spread through sneezing and coughing, has now been found to spread even through breathing.
- People with flu can generate infectious aerosols (tiny infectious droplets that stay suspended in the air for a long time) even when they are not coughing, and especially during the first days of illness.
- Large quantities of the infectious virus could be found in the exhaled breath of infected patients.
"People with flu generate infectious aerosols (tiny droplets that stay suspended in the air for a long time) even when they are not coughing, and especially during the first days of illness. So when someone is coming down with influenza, they should go home and not remain in the workplace and infect others."
Researchers from the University of Maryland, San Jose State University, Missouri Western State University and University of California, Berkeley contributed to this study funded by the Centers for Disease Control and Prevention (CDC) and the National Institutes of Health.
Dr. Milton and his research team captured and characterized influenza virus in exhaled breath from 142 confirmed cases of people with influenza during natural breathing, prompted speech, spontaneous coughing, and sneezing, and assessed the infectivity of naturally occurring influenza aerosols.
The participants provided 218 nasopharyngeal swabs and 218 30-minute samples of exhaled breath, spontaneous coughing, and sneezing on the first, second, and third days after the onset of symptoms.
Surprisingly, 11 (48%) of the 23 fine aerosol samples acquired in the absence of coughing had detectable viral RNA and 8 of these 11 contained infectious virus, suggesting that coughing was not necessary for the infectious aerosol generation in the fine aerosol droplets.
"The study findings suggest that keeping surfaces clean, washing our hands all the time, and avoiding people who are coughing does not provide complete protection from getting the flu," said Sheryl Ehrman, Don Beall Dean of the Charles W. Davidson College of Engineering at San José State University. "Staying home and out of public spaces could make a difference in the spread of the influenza virus."
According to the authors, the findings could be used to improve mathematical models of the risk of airborne influenza transmission from people with symptomatic illness and to develop more effective public health interventions and to control and reduce the impact of influenza epidemics and pandemics.
Improvements could be made to ventilation systems to reduce transmission risk in offices, school classrooms, and subway cars, for example. Meanwhile, we can all heed the advice to stay home, if possible, when we are beginning to get sick to prevent even greater numbers of flu cases. And, get vaccinated -- it is not perfect but does prevent a significant amount of severe illness.
Reference
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Flu may be spread just by breathing, new study shows; coughing and sneezing not required - (https://sph.umd.edu/news-item/flu-may-be-spread-just-breathing-new-study-shows-coughing-and-sneezing-not-required)
Source-Eurekalert