The flu is transmitted before the onset of obvious symptoms
Last reviewed: 17.10.2021
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Researchers from the Imperial College in London studied the ways of transmitting the influenza virus on ferrets. They suggested that the disease can be transmitted even before the onset of obvious symptoms.
If the medical hypothesis is confirmed, it means that a person already infected can not learn about it. That is why it is so difficult to contain the waves of epidemics of this disease.
The work of scientists was carried out with the assistance of the National Institute for Health Research and the Imperial Center for Biomedical Research. The results of the research are published in the journal PLoS ONE.
For experiments, scientists chose ferrets, because these animals are subject to the same flu strains as humans.
Healthy ferrets were put in contact with influenza patients: they were briefly placed in a cage with infected individuals for a short time.
As it turned out, the sick ferrets managed to "share" the virus with the healthy ones even before the first appearance of the last symptoms of the disease. Also, scientists noticed that it does not really matter whether animals are in one or the neighboring cells.
According to the lead author of the research, Wendy Barclay, the results of these studies are especially important for planning methods for controlling influenza epidemics.
"Despite personal diagnosis of his condition, a person may not suspect that he is already sick. This is the greatest danger, because already infected people are not isolated, but continue to communicate with healthy people, "the author of the study explains.
During research on ferrets, specialists found that the first signs of the disease appear 24 hours after infection, and sneeze animals began 48 hours later.
This confirms the results of earlier studies, which prove that for the transmission of the influenza virus a person does not necessarily have to sneeze - and already the microbes are thrown into the air during normal breathing.
In addition, experts concluded that at later stages, 5-6 days after infection, the infection is transmitted less often and not so "clings". People can return to their normal daily activities.
"Ferrets are the best option, which is suitable for studying the ways of influenza transmission, however, the interpretation of the results of work with respect to humans needs to be treated more carefully, because the symptoms and course of the disease depend on the specific strain of influenza," said Kim Roberts from Trinity College in Dublin.