Compiled by veteran medical journalist Brian Owens, this roundup of some of the newest science on the COVID-19 pandemic, straight from the scientific journals, is presented by Hakai Magazine in partnership with The Tyee.
Smokers have more viral 'entry points' in their lungs
Smokers and people with chronic obstructive pulmonary disease have higher levels of the ACE2 enzyme in their lungs — the receptor that SARS-CoV-2 uses to enter cells, according to researchers from the University of British Columbia. This may put them at higher risk of more severe infections. Non-smokers and former smokers had lower levels of ACE2.
European Respiratory Journal, April 9, 2020
Most coronaviruses are seasonal, but SARS-CoV-2 might not be
Researchers studying common coronaviruses that infect humans over the past 10 years in Michigan have found that most are sharply seasonal, appearing between December and May, and peaking in January and February. But so far there is no evidence that this will be the case for SARS-CoV-2, the virus that causes COVID-19. A report by an expert committee of the U.S. National Academies of Science found that while some lab studies indicate a lower survival of the virus at higher temperatures, there are many other factors that affect the virus’s circulation in the real world, and some warmer countries like Australia are experiencing a rapid spread. Another study of the virus in several Chinese cities found no difference between sunnier, warmer areas, and cloudier, cooler ones.
Journal of Infectious Diseases, April 4, 2020
National Academies of Sciences report, April 7, 2020
European Respiratory Journal, April 9, 2020
Identifying the cells that SARS-CoV-2 attacks
Researchers in Germany examined lung cells from uninfected people and found that the ACE2 receptor that SARS-CoV-2 uses to enter cells is mostly found in cells that develop into respiratory tract cells lined with hair-like projections called cilia. Respiratory tract cells sweep mucus and bacteria out of the lungs. Researchers also found that the density of ACE2 receptors increased with age and was higher in men than women. Knowing which cells the virus targets could be useful in the development of therapies.
The EMBO Journal, April 4, 2020
Cats and ferrets are susceptible to SARS-CoV-2
As part of the search for animal models to use to study COVID-19, researchers tested whether the virus that causes it, SARS-CoV-2, could infect a variety of domestic animals. They found that the virus replicates poorly in dogs, pigs, chickens and ducks, but ferrets and cats can be infected. There is no evidence that cats or ferrets infect humans.
Will Canada have enough critical care beds?
A modelling study by researchers at Dalhousie University in Halifax has found that, without self-isolation of mild cases of COVID-19, demand for beds in intensive care units would greatly exceed supply in every province and the outbreak would peak in mid-June. If 40 per cent of mild cases self-isolate for the duration of their illness, the peak of the outbreak can be delayed for up to eight weeks, but demand for ICU beds would still exceed supply. This shows the importance of widespread testing to identify those who are infected and ensure that a higher proportion of the population is practicing strict self-isolation.
Periodic physical distancing could help control pandemic
A model based on data from Ontario indicates that periodic bouts of physical distancing and other control measures over the course of two years could help preserve health-system capacity and prevent intensive care units from being overwhelmed, while allowing us to have occasional psychological and economic breaks from the restrictions on daily life.
Quarantine can be effective, but people need support
Quarantine of people exposed to suspected or confirmed cases could reduce infections by between 44 and 81 per cent, and deaths by between 31 and 63 per cent, according to a systematic review of studies that used mathematical models to predict outcomes of outbreaks of COVID-19, SARS and MERS. Combining quarantine with other measures like school closures, travel restrictions and physical distancing was even more effective. But people need to be sure they can manage the hardships of quarantine. A survey in Israel found that when respondents were told they would be compensated for lost income, 94 per cent said they would comply with a self-quarantine order. Without compensation, the compliance rate dropped to less than 57 per cent.
Cochrane Systematic Review, April 8, 2020
The physical and mental toll of confinement
People in areas more affected by COVID-19 had poorer physical and mental health and lower life satisfaction, according to a study of more than 300 people in 64 Chinese cities conducted after one month of confinement measures. Those who stopped work reported worse mental and physical health conditions as well as distress, as did those with existing chronic health issues. Surprisingly, people who exercised more than 2.5 hours a day reported worse life satisfaction, while those who exercised 30 minutes or less reported positive life satisfaction. Identifying those more likely to be affected by long periods of confinement will help target assistance to those who need it most.
Psychiatry Research, April 4, 2020
Screen of 10,000 compounds identifies six with promise
Researchers tested more than 10,000 compounds — some approved drugs, some drug candidates, and some virtual compounds in a computer, and identified six candidates that may help treat COVID-19. One, an anti-inflammatory drug called Ebselen, showed particular promise in test tube studies.
Exploiting wildlife increases chances of viral outbreaks
Close contact between wildlife and humans through hunting, trade, habitat loss and urbanization increases the risk of new viruses jumping from animals to humans. The risk appears to be highest from domestic animals, and from threatened and endangered wild animals that have declined due to exploitation and loss of habitat. The conversion of natural lands to agriculture also increases contact between humans and animals, and raises the risk of viruses making the leap to humans.
Proceedings of the Royal Society B, April 8, 2020
Landscape Ecology, April 1, 2020 ![[Tyee]](/design-article.thetyee.ca/ui/img/yellowblob.png){kind=small}
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