A COVID Culprit: Crowded Households. And More News from Science Journals

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.

Crowded households drive uneven spread of COVID-19 in Vancouver

Having more people in a household can have a significant effect on COVID-19 transmission, confounding attempts to limit community transmission with blanket stay-at-home orders, according to a study that compared infection rates in two Vancouver-area health regions.

The study found that the Fraser Health region had more large households than the Vancouver Coastal Health region, and that that difference alone could account for the higher infection rates seen in the Fraser Health region. The researchers say that, in regions with larger households, offering individuals a place to isolate outside their households can be more effective at reducing transmission than a one-size-fits-all lockdown.

Journal of the Royal Society Interface, April 27, 2021

Pregnant people infected with COVID-19 face higher mortality and risk of pre-term birth

People who contracted COVID-19 while pregnant are more than 20 times more likely to die than those who were not infected, according to a study of more than 2,000 women around the world. The women and their babies were also more likely to experience pre-term birth, preeclampsia and admission to intensive care, particularly if the mother had a more severe course of the disease.

The risk of transmitting the virus from mother to baby was relatively low — around 11 per cent in the global study, and just two per cent in another study from hospitals in Massachusetts, and the infections were usually mild. But there could be more serious indirect risks to the babies. Pregnant people with more severe COVID-19 infections were more likely to give birth prematurely, which can often lead to acute and chronic complications, including respiratory distress, chronic health problems and developmental disabilities.

Another study found that it may not be the virus itself that is responsible for the elevated risk of pre-term birth or preeclampsia, but instead the mother’s own immune response. Researchers found that while evidence of the virus in the placenta is rare, the placenta in infected mothers tended to exhibit a much higher level of immune system activity than those who were not infected, which could have adverse effects on the pregnancy.

And it is not just the physical effects of COVID-19 that bring risks to pregnant people and their babies. A survey conducted during the first wave of the pandemic found that large numbers of pregnant and postpartum women scored high for symptoms of anxiety, depression, loneliness and post-traumatic stress in relation to COVID-19, all of which could adversely affect not only their own health but also infant outcomes, mother-infant bonding, and later offspring health.

JAMA Pediatrics, April 22, 2021

JAMA Network Open, April 23, 2021

Med, April 22, 2021

PLOS One, April 21, 2021

Regular drug users report increased, and riskier, use during the pandemic in Canada

Nearly half of regular drug users report increased use of drugs during the pandemic, according to a survey by Canada’s Centre for Addiction and Mental Health, while almost 40 per cent said they believed they were more at risk of an overdose due to supply disruptions that made drugs more expensive, harder to get and of unknown origin. Nearly half of those who use syringes and other paraphernalia said they started re-using or sharing due to reduced hours or COVID restrictions that decreased access to harm reduction or needle exchange programs. And seven per cent said they had relapsed during the pandemic. Disruptions to drug supply have also been associated with an increase in overdose deaths and other harms. In British Columbia, the number of illicit drug overdose deaths increased by 72 per cent between March and July 2020 compared to the year before.

International Journal of Drug Policy, April 20, 2021

More severe initial infections linked to worse long-term outcomes

Those with more severe initial bouts of COVID-19 are at greater risk of long-term complications, including an increased risk of death, than those with milder infections in the six months following their illness. But even those who had only mild cases are not out of the woods — after surviving the initial infection, all COVID-19 survivors had an almost 60 per cent increased risk of death over the following six months compared with the general population. They were also more likely to require medical assistance for additional problems such respiratory conditions, nervous system disorders, mental health problems, metabolic and cardiovascular disorders, malaise, fatigue, musculoskeletal pain and anaemia. People who experienced long-term symptoms also showed an increased use of various medications, including antidepressants, anti-anxiety drugs and pain medications.

Nature, April 22, 2021

Shift workers more likely to be hospitalized with COVID-19

People who work shifts are significantly more likely to catch COVID-19, and to end up in the hospital if they do, than those who work regular hours. Shift work was still associated with higher risk even after accounting for the type of work and other risk factors such as obesity, age and ethnicity. Previous studies have found that shift work increases the risk of respiratory disease, diabetes, cancer and infectious diseases, possibly due to sleep deprivation, poor diet and disruption of the body’s circadian rhythms.

Thorax, April 26, 2021

Time passes slowly in lockdown, especially if you’re depressed

The feeling of time seeming to pass more slowly was widely reported during lockdowns in the early stages of the COVID-19 pandemic, and a new study from the U.K. has found that the feeling seems to be a common feature of subsequent lockdowns as well. More than 80 per cent of people reported experiencing distortion to the passage of time during the second national lockdown in England, and the feeling was particularly common among those who are depressed, self-isolating or dissatisfied with their social interactions.

PLOS One, April 20, 2021

Different immune responses linked to asymptomatic vs. severe COVID-19

Differences in a person’s immune response to COVID-19 could determine whether they get a severe form of the disease, or show no symptoms at all. Researchers found that asymptomatic people had high levels of antibody-producing B cells, while people with more serious symptoms had lost these protective cell types but had more cells that cause inflammation. These differences in the immune response could help explain the serious lung inflammation and blood clotting symptoms seen in patients with severe disease and could be used to identify potential targets for developing new treatments.

Nature Medicine, April 20, 2021

Guilt leads people to underreport COVID-19 violations

Studies of whether people are complying with COVID-19 rules frequently rely on data from surveys — but guilt and social pressure often leads people to lie about how well they are following the rules. A study found that using a guilt-free strategy — prefacing questions with a face-saving preamble that acknowledged that not everyone is willing or able to comply with the rules — increased respondents’ willingness to report their own non-compliance by nine to 16 percentage points, leading to better information about how well the rules are working.

PLOS One, April 21, 2021

Ship traffic dropped at the beginning of the pandemic

Ship traffic fell in more than 70 per cent of countries around the world at the beginning of the pandemic, leading to environmental benefits such as clearer water in Venice and reduced underwater noise in Vancouver. A study of these changes in traffic found that global declines peaked in April 2020, but by June ship movements began to increase again as many pandemic-related restrictions began to be lifted. The largest and longest-lasting reductions were in passenger vessels, while tankers, cargo vessels and fishing boats were less affected.

Nature Communications, April 27, 2021

People can transmit the virus to cats

Veterinarians in the U.K. have identified two cases where people transmitted COVID-19 to their pet cat. The infected cats developed mild or severe respiratory disease. The researchers say this ability of the virus to infect different species shows it is important to monitor for human-to-cat, cat-to-cat and cat-to-human transmission, to keep an eye on unexpected avenues of transmission.

Vet Record, April 22, 2021