Dödligt virus från Kina orsakar panik (SARS-CoV-2, COVID-19)

People who whip off their masks to speak in public are missing the point, Dr. Andrea Lerner, a clinical associate at the National Institute of Allergy and Infectious Diseases, along with Fauci’s chief of Staff Greg Folkers, wrote in an article in the Journal of the American Medical Association.
They spoke out on defense of cloth masks -- recently attacked by Sen. Rand Paul -- and said taking tests regularly is not enough to absolve people of the need to wear a mask.
Masks block large particles that blast out of people’s mouths and noses.
“However, recent reports indicate that aerosols remaining in the air over longer distances or times also have been involved in SARS-CoV-2 transmission in certain circumstances, often in poorly ventilated enclosed spaces and associated with behaviors such as singing, shouting, or breathing heavily during exercise,” Lerner, Folkers and Fauci wrote.
“Light-scattering experiments indicate that 1 minute of loud speaking potentially can generate more than 1,000 virion-containing aerosols that may linger in the air in a closed, stagnant environment,” they added.
"Therefore, the commonly observed practice of individuals removing their mask when speaking is not advisable.”
And with winter coming, people will have to wear masks even more, they said.
“Recent evidence suggests that up to 40% to 45% of people infected with SARS-CoV-2 may never be symptomatic but still can transmit the virus,” they added. “Viral spread from people without symptoms may account for more than 50% of transmission events in COVID-19 outbreak.”
Testing can help but is not enough to prove someone is free of infection. “No test is perfect; all have a lower limit of detection for viral material and the potential for false negatives. In addition, the result of a test represents just one point in time and does not indicate an individual’s status outside of the moment the specimen was collected,” they noted.
And cloth masks can work just fine. “Surgical masks can reduce respiratory virus shedding in exhaled breath, and the filtering efficacy of some materials used in cloth masks may approach that of surgical masks,” they noted.