The influenza (flu) virus is easier to spread than previously thought, according to a new study led by the University of Maryland (USA) and funded by the Centers for Disease Control and Prevention (CDC). ) and the National Institutes of Health.
It was commonly believed that we could get the flu by being exposed to the cough or sneeze of an infected person or by touching contaminated surfaces. However, new data on flu transmission reveals that we can spread it to others simply by breathing.
The study, published in the Proceedings of the National Academy of Sciences , provides new evidence of the potential importance of airborne flu transmission, due to the large amounts of infectious viruses found in the breath exhaled by people suffering from the flu.
“We found that the flu cases contaminated the air around them with infectious viruses simply by breathing, without coughing or sneezing,” explained Donald Milton, leader of the study. “People with the flu make infectious aerosols (tiny droplets that remain suspended in the air for a long time) even when they are not coughing, and especially during the first few days of the illness. Therefore, when someone contracts the influenza virus, you must go home and not stay in the workplace and infect others . “
Tests
The researchers captured and characterized the influenza virus in the exhaled breath of 142 confirmed cases of people with influenza during natural respiration, speaking, spontaneous coughing and sneezing, and evaluated the virus’s ability to infect using sprays. In total, 218 nasopharyngeal swabs and 218 30-minute samples of exhaled breath, spontaneous cough, and sneezing were obtained on the first, second, and third days after the onset of flu symptoms.
Analysis of the samples showed that a significant number of flu patients routinely shed the infectious virus, with particles small enough to pose a risk of airborne transmission.
As if this were not enough, 11 of the 23 samples in the absence of cough had detectable viral RNA and 8 infectious virus, showing that coughing was not necessary to achieve a potentially infectious spray.
“The study findings suggest that keeping surfaces clean, washing our hands all the time, and avoiding coughing people does not provide complete protection against the flu, ” says Sheryl Ehrman, a co-author of the paper.
Isolating yourself during the flu seems to be the only way to prevent ourselves from infecting others. And, of course, get vaccinated. It is not a 100% effective method but it significantly prevents contagion.
According to the authors, these findings could be used to improve mathematical models of the risk of airborne influenza transmission by people with symptomatic illnesses and to develop more effective public health interventions and to control and reduce the impact of influenza epidemics and pandemics.
Reference: Jing Yan et al. Infectious virus in exhaled breath of symptomatic seasonal influenza cases from a college community, bioRxiv (2017). DOI: 10.1101 / 194985
