Coronavirus science | Week in review: Face mask redesigned, recovery, and retesting after infection



READ | Researchers upgrade face masks to improve both comfort and protection

As Covid-19 spreads and masks become mandatory in many more parts of the world, there have been plenty of debates about which types of masks are most effective. The valve mask, for example, provides comfort, but it doesn’t protect other people against droplets that escape through the vents. Some prefer masks with elastic bands that loop around the ears, while others prefer simple cotton buffs.

Research has shown that some masks are more effective than others, but even the simplest single-layer cotton mask can decrease the amount of droplets expelled. Even though we theoretically understand this, masks are, however, still a bit of a struggle for some.

Now, researchers from the Georgia Institute of Technology have designed a new mask to incorporate protection and comfort – and are providing plans so that people can make it themselves.

The full research is published in The Journal of the Textile Institute, and according to a press release, the modular Georgia Tech mask combines a barrier filtration material with stretchable fabric to provide a comforting fit while staying in place.

The prototypes have hook and eye fasteners on the back to keep the masks secure. There is also a pocket for an additional filter to add protection. The researchers found that even after 20 washes, the prototype didn’t shrink or lose its shape.

READ | Based on the Italy outbreak, researchers suggest being tested a month after recovering from infection

You got infected with Covid-19, recovered and now want to return to your daily life. But a new study on Italian survivors indicate that you might still be carrying the virus around a month after you started exhibiting symptoms.

Published in BMJ Open, the research focused on how long viral shedding of SARS-CoV-2 goes on for, based on population data. This is important to understand as healthcare workers could be swamped with retesting to clear an infected patient.

They also wanted to determine the probability of viral clearance confirmation with two negative swabs, and what factors might possibly influence their outcomes.

They assessed the follow-ups of 1 162 patients in the Regio Emilia province in northern Italy, one of the hardest-hit regions during their outbreak a month after diagnosis and symptom onset to see how many patients were still carrying the viral load of the virus, and how many had been completely cleared.

From that group, 172 people died, most having been hospitalised with an average age of almost 80 years.

READ | In some cases, the damage can be extensive, and recovery could take time - but there is hope

Recovery from Covid-19 can be a long process, but there's some hope at the end of the tunnel.

Austrian and French researchers at the European Respiratory Society International Congress presented more evidence of the long-term lung and heart damage caused by the coronavirus, but are optimistic that the body eventually heals itself with time and physical rehabilitation.

This research is the first wave of studies on the recovery of Covid-19 patients.

So far, studies have been focusing on acute cases and their treatment, but we've reached a point in the pandemic where follow-up studies on recoveries are finally being presented.

The first presentation focused on Austrian coronavirus patients hospitalised at the University Clinic of Internal Medicine in Innsbruck, the St Vinzenz Hospital in Zams and the cardio-pulmonary rehabilitation centre in Münster, Germany. The sample for their presented data is still small (86), but has since grown to include over 150 participants.

READ | Researchers think they have found a new link between Covid-19 severity and comorbidities

Scientists might have found a new link between chronic disease and Covid-19 that could explain why patients with comorbidities are so susceptible to the virus.

They think the answer may lie with plasmin, a type of enzyme in the blood that degrades plasma proteins. Its levels are normally elevated in those with underlying medical conditions like hypertension, diabetes, cardiovascular disease, cerebrovascular disease, and kidney disease.

One of these plasma proteins is fibrin, which appears when the blood is clotting and impedes the flow of blood. When the fibrin is broken down through fibrinolysis, protein fragments remain behind called D-dimer.

According to the study published in Physiological Reviews, the plasmin makes the virus more deadly and infectious by cleaving the spike proteins it uses to invade cells through the ACE2 receptors.

"Extracellular cleavage of virus envelope fusion glycoproteins by host cellular proteases is a prerequisite for the infectivity of respiratory viruses. The presence of a polybasic cleavage site that can be cleaved by furin-like proteases is a signature of several highly pathogenic avian influenza viruses."

READ | Mapping Covid-19's tracks as it attacks the body

The process of scientists trying to understand how the coronavirus operates has been likened to detectives investigating a crime. To better understand the perpetrator, they first had to uncover its modus operandi in the human body, i.e. which cells it targets, and why.

These hotspots have recently been mapped in a study published in Cell Reports, where 28 SARS-CoV-2 and coronavirus-associated receptors and factors (SCARFS) were investigated as "accomplices" to the virus, serving as gateways for infection into various organ cells.

Let's start with cause of death. Post-mortems confirm that victims had major lung damage inflicted by Covid-19-induced pneumonia. It also wreaks havoc on the heart, kidney, liver and gastrointestinal tract, and has been proven to have some neurological impact on the brain.

"What causes the wide range of clinical phenotypes observed in people infected with SARS-CoV-2 is not yet understood," write the investigative scientists.

"It remains unclear which of these pathologies are caused by direct infection of the organs affected or indirect effects mediated by systemic inflammatory responses or comorbidities. A prerequisite to resolving these questions is to gain a better understanding of the tropism of the virus, i.e. which tissues and cell types are permissive to SARS-CoV-2 infection."


SA cases update: 

The latest number of confirmed cases is 648 214.

According to the latest update, 15 427 deaths have been recorded in the country.

There have been 576 423 recoveries.

So far, more than 3.9 million tests have been conducted, with 18 620 new tests reported.

Global cases update:

For the latest global data, follow this interactive map from Johns Hopkins University & Medicine.

Early on Sunday morning, positive cases worldwide were more than 28.6 million, while deaths were more tan 917 000.

The United States had the most cases in the world - almost 6.48 million, as well as the most deaths - more than 193 000.


Latest news:

HEALTH TIPS (as recommended by the NICD and WHO)

• Maintain physical distancing – stay at least one metre away from somebody who is coughing or sneezing

• Practise frequent hand-washing, especially after direct contact with ill people or their environment

• Avoid touching your eyes, nose and mouth, as your hands touch many surfaces and could potentially transfer the virus

• Practise respiratory hygiene – cover your mouth with your bent elbow or tissue when you cough or sneeze. Remember to dispose the tissue immediately after use.

Image credit: Getty Images

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