Researchers at San Jose State University, UC Berkeley, and the University of Maryland found in their study that the flu can be transmitted to other people through normal breathing. The experts published the results of their study in the journal Proceedings of the National Academy of Sciences.
Physicians investigate how the flu can be transmitted.
So far, most people have certainly thought that they have been infected with flu after being exposed to the coughing or sneezing of an infected person or touching a contaminated surface. Researchers have now found out that the flu can also be passed on to other people through normal breathing.
People with influenza have large amounts of infectious viruses in their breath
The work of the physicians provides new evidence for the importance of the airborne particles of the flu. This way the flu can easily be transmitted to other people. The scientists discovered large amounts of infectious virus in the breath, which were exhaled by the sick person. The study’s findings suggest that cleaning surfaces, washing hands, and preventing coughing does not provide complete protection against flu, says author Sheryl Ehrman of San Jose State University. However, if sufferers stay at home and do not move in public, this may inhibit the spread of the influenza virus, the expert adds.
Examination included 178 subjects
The study was conducted during the flu season from December 2012 to March 2013. For the investigation, 178 volunteer participants were recruited. These were mostly students with flu symptoms. During the time of the study, the researchers recorded and characterized the influenza virus in 142 of the volunteers with confirmed cases of the flu as they breathed, talked, coughed or sneezed.
How did the study go?
The physicians then assessed the severity of naturally occurring influenza aerosols. These tiny droplets hover for a long time in the air. The participants in the study swabbed 218 samples from their nasopharynx, the upper part of the pharynx, which lies directly behind the nose. They also provided 218 samples of exhaled air, spontaneous coughing and sneezing on the first, second and third day after the onset of influenza symptoms, which were taken over a 30-minute period, the researchers explain.
Influenza patients transmit the virus via the air
Analysis of the infectious virus recovered from these samples revealed that a significant number of influenza patients routinely deliver an infectious virus in tiny aerosol particles that can be transmitted through the air. Surprisingly, the study suggested that coughing or sneezing was not necessary to cause infection, say the doctors.
Diseased people should not leave the house
People suffering from influenza contaminate the air around them with the infectious virus. This is done by breathing, without the appearance of coughing or sneezing, says author Professor Dr. Donald Milton of the School of Public Health, University of Maryland. People with flu will produce infectious aerosols even if they do not cough, especially during the first days of sick leave. So, if people get the flu, they should stay at home and not go to work and infect other people, advises the expert.
Results could reduce effects of influenza epidemics
The researchers believe that the results of their study could be used to improve mathematical models on the risk of airborne flu transmission in people with influenza symptoms. This could help to better control and reduce the impact of influenza epidemics and pandemics.
Certain measures provide protection from the flu
Improvements could also be made to ventilation systems, for example, to reduce the risk of transmission in offices, classrooms and subway cars, the authors of the study explain. Although a flu vaccine does not guarantee that people will not catch the flu, such vaccination can also provide some protection and thus reduce the likelihood of people seriously getting the flu, experts explain.