No evidence supporting lab origin of SARS-CoV-2

5 minute read

And long covid continues to affect quality of life a year after infection, study finds.

Welcome to The Medical Republic’s COVID Catch-Up.

It’s the day’s covid-19 news in one convenient post. Email with any tips, comments or feedback.

8 July

No previous epidemics have been caused by the escape of engineered organisms from a laboratory, and the SARS-CoV-2 pandemic bears all the usual hallmarks of a pathogen crossing from animals to humans, experts say.
A non-peer-reviewed preprint study by an international group of researchers, published on Zenodo, reviews the evidence collected about the possible origins of SARS-CoV-2, and concludes that it is ‘remarkably’ similar to the spillover of SARS-CoV in China in 2002 and 2003.
All known human coronaviruses – both epidemic and endemic – have zoonotic origins, the authors wrote, and both SARS-CoV and SARS-CoV-2 were first detected in markets selling live animals such as civets and racoon dogs, which are known to be susceptible to SARS-CoV-related viruses.
Environmental samples taken at the Huanan market in Wuhan tested positive for SARS-CoV-2, particularly in the section of the market where people traded wildlife and domestic animals.
Commenting on the ‘lab leak’ theory of the origins of SARS-CoV-2, the authors noted that there are no documented examples of epidemics or pandemics caused by pathogens released from research activity.
“Viral genomic sequencing without cell culture, which was routinely performed at the WIV [Wuhan Institute of Virology], represents a negligible risk as viruses are inactivated during RNA extraction and no case of laboratory escape has been documented following the sequencing of viral samples,” the authors wrote.
They also pointed out that no cases of SARS-CoV-2 infection were detected among any laboratory staff at the Institute, and all were seronegative when tested in March 2020.
More to come.

Nearly 40% of people with mild covid-19 report ongoing symptoms such as fatigue, loss of taste or smell, breathlessness and headache nine months after infection.
A study of ‘long covid’, published in the Annals of Internal Medicine, looked at symptoms among 629 individuals who tested positive for SARS-CoV-2 but remained as outpatients. The mean age was 42 years, 61% were women, and 71% had no underlying risk factors.
Of the 410 individuals who responded to a survey at 7-9 months after initial infection, 39% reported at least one ongoing symptom, but one in ten had four persistent symptoms.
One-quarter of the 85 people who reported persistent fatigue said it restricted them in physically strenuous activity, and 60% of the 48 people who reported breathlessness said they experienced it walk up a slight hill or even hurrying along ground level.
“Most patients who reported loss of smell, headache, loss of taste, insomnia, myalgia, hair loss, cough, or loss of appetite reported their symptoms as at least moderate,” the authors wrote.
Meanwhile, a separate study of 96 people with acute covid – around one-third of whom were hospitalised with the infection – found more than three-quarters were still experiencing symptoms one year later.
More than half were experiencing reduced exercise capacity and fatigue, around one third experienced ‘problems finding words’ and one quarter had trouble sleeping.
Those with at least one persistent symptom had significantly lower physical and mental quality of life compared to patients without persistent symptoms.
The study, published in Clinical Infectious Diseases, also saw no correlation between levels of SARS-CoV-2 antibodies and risk of long covid.

Quarantined international travellers should be tested at day 16 and 17 after quarantine if there are any potential sources of exposure to covid-19 at the facility, even if they are asymptomatic, the Australian Health Protection Principal Committee has advised.
AHPPC said there was a need for ‘national understanding’ of travellers once they leave quarantine and return home, but didn’t specify what that understanding was supposed to be of. However they stressed that all travellers leaving quarantine should be on alert for covid symptoms, and test and self-isolate if they experience them at any time in the two weeks after leaving quarantine.
“Options are being explored to support post-quarantine testing at the national level,” AHPPC noted.

The New South Wales outbreak continues to grow, with an additional 38 new cases reported today, bringing the total number of infections in this outbreak to 395 since 16 June. Of these 38 new cases, 11 cases were infectious in the community.
And as a brutal reminder of the malignancy of this infection, there are currently 40 covid-19 cases in hospital, 11 people in intensive care and three on ventilators.
A total of eleven cases have been diagnosed at the SummitCare Baulkham Hills aged care facility – six residents and five staff.
This chart shows the difference in growth rates of various outbreaks in Australia, and does lend some weight to AMA president Omar Khorshid’s argument that Sydney would be in a better place had it locked down sooner.

As of yesterday, just over one in ten Australians has received two doses of any covid vaccine, according to the latest government figures.
That translates into 12.5% of those aged over 50 years and 21.5% of those aged over 70 years.

Some good news: global deaths from covid in the past week are at the lowest level since October 2020. But the bad news is infection rates have increased slightly again, after a long-running decline. The only part of the world not experiencing an increase in infections is the Americas, according to the latest World Health Organisation update.
Europe has recorded a 30% increase in cases, with the UK alone showing a 67% increase in new infections in the past week. Infection rates are also accelerating in Argentina, Brazil, Russia and Venezuela.

Here are the latest covid-19 infection numbers from around Australia to 9pm Wednesday:
National – 30,861 with 910 deaths
ACT – 124 (0)
NSW – 6025 (28)
NT – 185 (0)
QLD – 1729 (1)
SA – 813 (0)
TAS – 234 (0)
VIC – 20,718 (0)
WA – 1033 (0)

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