The new coronavirus can survive many hours on human skin if left undisturbed, a new study has found.

Though studies have shown that Covid-19 transmission largely occurs via aerosols and droplets, the authors of the new study published in Clinical Infectious Diseases said, “Proper hand hygiene is important to prevent the spread of SARS-CoV-2 infections.”

To avoid possibly infecting healthy volunteers, researchers conducted lab experiments using cadaver skin that would otherwise have been used for skin grafts. 

While influenza A virus survived less than two hours on human skin, the novel coronavirus survived for more than nine hours. Both were completely inactivated within 15 seconds by hand sanitizer containing 80 per cent alcohol.

The US Centers for Disease Control and Prevention recommends using an alcohol-based hand rubs or thoroughly washing hands with soap and water for at least 20 seconds.

Breathing with face masks does not affect lungs

Researchers have said the average face mask may be uncomfortable but does not limit the flow of oxygen to the lungs, even in people with severe lung diseases, Reuters stated in a report.

Researchers tested the effect of wearing surgical masks on gas exchange – the process by which the body adds oxygen to the blood while removing carbon dioxide – in 15 healthy physicians and 15 military veterans with severely impaired lungs via a quick-paced six-minute walk on a flat, hard surface.

Oxygen and carbon dioxide levels in the blood were measured before and after the walking test

Neither the healthy doctors nor the patients with diseased lungs showed any major changes in gas exchange measurements after the walking test or up to 30 minutes later.

Mask discomfort is likely not due to re-breathing of carbon dioxide and decreases in oxygen levels, the researchers reported in the journal Thorax.

Masks may be causing discomfort by irritating sensitive facial nerves, warming inhaled air, or inducing feelings of claustrophobia. Any such discomfort should not cause safety concerns, researchers said.

Infrared thermometers may be inaccurate

Non-contact infrared thermometers, now being used to screen for fever in public places, may not accurately measure body temperature in adults, a small study suggests.

In a study of 265 adults at two hospitals, Australian researchers compared infrared thermometers with “temporal artery” thermometers.

When body temperatures were below 99.5 degrees F (37.5 C), the devices yielded similar results. But for higher body temperatures, the non-contact thermometers “demonstrated poor accuracy,” with greater discrepancies as temperatures rose, according to a report published on Friday in the American Journal of Infection Control.

As only 37 study participants had fever, larger studies are needed to confirm these findings, researchers said.

Obstructive sleep apnea linked with worse Covid-19

A common sleep disorder appears to put Covid-19 patients at higher risk for critical illness, a new study has found.

Using Finnish national databases, researchers found that while the rates of infection with the new coronavirus were the same for people with and without obstructive sleep apnea (OSA), among people who did become infected, those with OSA had a five-fold higher risk of hospitalisation.

When people with OSA are asleep, their breathing stops briefly and then restarts, often multiple times during the night.

The study cannot prove that OSA caused more severe outcomes. But in a paper posted on medRxiv ahead of peer review, researchers advise doctors evaluating patients with suspected or confirmed coronavirus infection to recognize that the sleep disorder is a risk factor for severe Covid-19.