Chinese researchers have confirmed a case of asymptomatic transmission of the new coronavirus: A 20-year-old woman from Wuhan passed it to five of her family members but never got physically sick herself.
The case study is the first concrete evidence that a person showing no symptoms can pass the coronavirus to others – a fact that could make curbing the outbreak even more challenging.
The researchers behind the finding said the 20-year-old woman was isolated and closely observed at the Fifth People’s Hospital of Anyang. She never become physically ill, even after her family members developed fevers. Two of them got severe pneumonia.
For now, the woman’s asymptomatic transmission appears to be an anomaly, but health experts have documented other instances in which people tested positive for the virus without showing symptoms.
A report from the Chinese Centre for Disease Control and Prevention analysed records of all of China’s reported cases of the virus from December 8 to February 11 and found that 1.2 percent of patients confirmed to be infected showed no symptoms.
A far higher portion of asymptomatic cases was found on the Diamond Princess cruise ship, where 322 of 621 people tested positive but showed no symptoms.
“It’s very clear that the people who are getting caught in that umbrella of reporting are the people that present themselves to a hospital,” Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said at a briefing on February 6.
“There’s another whole cohort that is either asymptomatic or minimally symptomatic.”
The Chinese woman tested positive for the virus, but never got sick
The 20-year-old woman in the new case study lives in Wuhan – the city where the outbreak started – but travelled to Anyang on January 10. Three days later, she went with five family members to visit a sick patient (who did not have the coronavirus) at the Anyang District Hospital.
On January 17, one of the woman’s family members came down with a fever and sore throat. The following week, the other four relatives developed a fever and respiratory symptoms. Those relatives were admitted to the Fifth People’s Hospital on January 26.
All of the family members tested positive for the coronavirus. The only person they’d had contact with who had been in Wuhan was their 20-year-old relative.
When doctors initially tested the young woman for the coronavirus, the results came back negative. Her CT scan was normal, too. But a day later, she tested positive for the virus even though she wasn’t showing any symptoms. By February 11, the woman still had no fever, cough, sore throat, or gastrointestinal issues.
Doctors concluded that the woman’s incubation period – the time during which she was infectious – was 19 days.
The US and many other countries have established quarantine rules for travellers from Wuhan based on that 14-day window.
Asymptomatic transmission in Germany?
Most of the coronavirus cases so far have been mild, but the virus has killed more than 2,200 people and infected more than 76,000. Though the majority of cases are on the Chinese mainland, the virus has spread to 29 other countries.
A case of asymptomatic transmission similar to the one described in the new case study was previously identified in Germany. But that research turned out to be flawed.
According to a letter published in the New England Journal of Medicine, a woman from Shanghai transmitted the virus to a 33-year-old German businessman in January. Three days later, he felt better and went back to work, then infected at least two of his colleagues. But the researchers had not spoken with the woman, who had in fact experienced mild symptoms at the time of transmission.
That left scientists unsure as to whether people who never experience any symptoms can transmit the disease – until today.
This article was originally published by Business Insider.
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Governments seek buyer as Quebec COVID-19 vaccine manufacturer Medicago set to close
Quebec Economy Minister Pierre Fitzgibbon said Friday the province has had preliminary talks with potential buyers in the pharmaceutical sector to keep Medicago’s expertise and skilled workforce in Quebec. He said both the Quebec and federal governments would be willing to put in money to secure a deal.
“We can’t operate it ourselves; the government will not be the main shareholder,” Fitzgibbon said. “But if there is a pharmaceutical company that considers it’s worth continuing, we’re ready to help.”
Mitsubishi Chemical said Thursday it would stop marketing the Medicago-produced Covifenz vaccine, which is plant-based and was approved by Health Canada one year ago for adults aged 18 to 64.
The Japanese chemical company said it had been preparing to commercially produce the Covifenz vaccine but decided against doing so because of the “significant changes” in the COVID-19 vaccine environment. The company said it would dissolve Medicago because it is no longer “viable” to continue marketing its products.
“In light of significant changes to the COVID-19 vaccine landscape since the approval of Covifenz, and after a comprehensive review of the current global demand and market environment for COVID-19 vaccines and Medicago’s challenges in transitioning to commercial-scale production, the (company) has determined that it will not pursue the commercialization of Covifenz,” Mitsubishi Chemical said in a statement.
Following the announcement, Medicago issued a statement thanking its employees. “The Medicago team has pushed scientific boundaries and we know that they will continue to make incredible contributions to innovation and biopharmaceutical’s sector.”
Canada invested $173 million in Medicago in 2020 to support development of the Covifenz vaccine and help Medicago expand its production facility in Quebec City.
On Thursday, Innovation, Science and Industry Minister François-Philippe Champagne told reporters the federal government is in “solution mode.”
“Our first order of business is really to try to find a partner who can help us preserve the jobs, preserve the technology and the intellectual property,” Champagne said.
The minister acknowledged that mRNA vaccine technology for COVID-19 became dominant as it “seemed to be most effective.”
But Medicago’s plant-based vaccine was still “promising,” Champagne said.
“Everyone agreed that the plant-based vaccine could very well help in a future pandemic,” Champagne said.
Speaking to reporters on Montreal’s South Shore Friday, Fitzgibbon said the company informed the province at the end of December it intended to pull the plug on Medicago.
In May 2015, Quebec and Ottawa announced loans of $60 million and $8 million, respectively, for the construction of a complex in the Quebec City region to house Medicago’s activities.
“The challenge is not (getting the loan repaid), it’s how we can save the jobs, save this company,” Fitzgibbon said.
While Canada authorized Medicago’s vaccine in February 2022, it was rejected for emergency use by the World Health Organization in March because tobacco company Philip Morris was a minority shareholder in the company, contravening a policy adopted in 2005 by the United Nations agency.
Quebec City Mayor Bruno Marchand said on Twitter he was saddened by the closure of the company.
“My thoughts are with the families who learned some very sad news,” Marchand said Thursday evening. “We have to roll up our sleeves to keep all this expertise in the field of health innovation in Quebec City.”
This report by The Canadian Press was first published Feb. 3, 2023.
Sidhartha Banerjee, The Canadian Press
Bird flu keeps spreading beyond birds. Scientists worry it signals a growing threat to humans, too
As a deadly form of avian influenza continues ravaging bird populations around much of the world, scientists are tracking infections among other animals — including various types of mammals more closely related to humans.
Throughout the last year, Canadian and U.S. officials detected highly pathogenic H5N1 avian flu in a range of species, from bears to foxes. In January, France’s national reference laboratory announced that a cat suffered severe neurological symptoms from an infection in late 2022, with the virus showing genetic characteristics of adaptation to mammals.
Most concerning, multiple researchers said, was a large, recent outbreak on a Spanish mink farm.
Last October, farm workers began noticing a spike in deaths among the animals, with sick minks experiencing an array of dire symptoms like loss of appetite, excessive saliva, bloody snouts, tremors, and a lack of muscle control.
The culprit wound up being H5N1, marking the first known instance of this kind of avian influenza infection among farmed minks in Europe, notes a study published in Eurosurveillance this month.
“Our findings also indicate that an onward transmission of the virus to other minks may have taken place in the affected farm,” the researchers wrote.
Eventually, the entire population of minks was either killed or culled — more than 50,000 animals in total.
That’s a major shift, after only sporadic cases among humans and other mammals over the last decade, according to Michelle Wille, a researcher at the University of Sydney who focuses on the dynamics of wild bird viruses.
“This outbreak signals the very real potential for the emergence of mammal-to-mammal transmission,” she said in email correspondence with CBC News.
It’s only one farm, and notably, none of the workers — who all wore face shields, masks, and disposable overalls — got infected.
But the concern now, said Toronto-based infectious disease specialist Dr. Isaac Bogoch, is if this virus mutates in a way that allows it to become increasingly transmissible between mammals, including humans, “it could have deadly consequences.”
“This is an infection that has epidemic and pandemic potential,” he said. “I don’t know if people recognize how big a deal this is.”
H5N1 has high mortality rate
Among birds, the mortality rate of this strain of highly pathogenic avian influenza can be close to 100 per cent, causing devastation to both wild bird populations and poultry farms.
It’s also often deadly for other mammals, humans included.
The World Health Organization (WHO) has documented 240 cases of H5N1 avian influenza within four Western Pacific countries — including China, Cambodia, Laos, and Vietnam — over the last two decades. More than half of the infected individuals died.
Global WHO figures show more than 870 human cases were reported from 2003 to 2022, along with at least 450 deaths — a fatality rate of more than 50 per cent.
Bogoch said the reported death toll may be an overestimate, since not all infections may be detected, though it’s clear people can “get very, very sick from these infections.”
Most human infections also appeared to involve people having direct contact with infected birds. Real-world mink-to-mink transmission now firmly suggests H5N1 is now “poised to emerge in mammals,” Wille said — and while the outbreak in Spain may be the first reported instance of mammalian spread, it may not be the last.
“A virus which has evolved on a mink farm and subsequently infects farm workers exposed to infected animals is a highly plausible route for the emergence of a virus capable of human-to-human transmission to emerge,” she warned.
Louise Moncla, an assistant professor of pathobiology at the University of Pennsylvania school of veterinary medicine, explained that having an “intermediary host” is a common mechanism through which viruses adapt to new host species.
“And so what’s concerning about this is that this is exactly the kind of scenario you would expect to see that could lead to this type of adaptation, that could allow these viruses to replicate better in other mammals — like us.”
Surveillance, vaccines both needed
What’s more reassuring is the ongoing development of influenza vaccines, giving humanity a head start on the well-known threat posed by bird flu.
Wille noted the earlier spread of H7N9, another avian influenza strain which caused hundreds of human cases in the early 2010s, prompted similar concern that the virus would acquire the mutations needed for ongoing human-to-human transmission.
“However, a very aggressive and successful poultry vaccination campaign ultimately stopped all human cases,” she added.
But while several H5N1 avian influenza vaccines have been produced, including one manufactured in Canada, there’s no option approved for public use in this country.
To ward off the potential threat this strain poses to human health, Bogoch said ongoing surveillance and vaccine production needs to remain top-of-mind for both policy makers and vaccine manufacturers.
Dr. Jan Hajek, an infectious diseases physician at Vancouver General Hospital, also questioned whether it’s time to wind down global mink farming, given the spread of various viruses, from avian influenza to SARS-CoV-2, the virus behind COVID-19.
“We’re closely related to minks and ferrets, in terms of influenza risks … if it’s propagating to minks, and killing minks, it’s worrisome to us,” he said.
In 2021, B.C. officials announced an end to mink farming across the province, saying the farms can be reservoirs for viruses and represent an ongoing danger to public health. All mink farm operations must be shut down, with all of the pelts sold, by April 2025.
However, other provinces — and plenty of countries — do intend to keep their mink farms operating.
“Is it responsible to have these kinds of farming conditions where these types of events can occur?” questioned Moncla. “If we’re going to keep having these types of farms, what can we do to make this safer?”
6,654 students facing suspension due to out-of-date immunization records
The Windsor-Essex County Health Unit (WECHU) has issued about 6,654 suspension orders to students who do not meet immunization requirements.
WECHU completed a review of all elementary student immunization records in December and more than 12,000 students received a notice.
These students were either overdue for one or more vaccines required to attend school, or their immunization records were not updated with the health unit.
“While many of these vaccines are normally administered by primary health care providers, parents and guardians of children who received their vaccines from their health care provider still need to report this information to the health unit,” said a WECHU news release.
The Immunization of School Pupils Act (ISPA) (1990), Section 11, Subsections (1) and (2) requires public health units to maintain and review vaccine records for every student attending school and to enforce a school suspension for incomplete immunization information. As the next step of the ISPA enforcement process, orders were mailed out to students that do not meet this requirement.
WECHU said this is the final notice.
The suspension order notifies parents and guardians that immunization records must be updated to the WECHU by Thursday, March 16, at 6 p.m. or their child will be suspended for up to 20 days from school, starting Monday, March 20, 2023. Once parents and guardians provide the missing immunization information to the WECHU, the student is removed from the suspension list and can attend school again.
Under the ISPA , children can be exempted from immunization for medical reasons or due to conscience or religious belief.
Families can book immunization appointments with their health care provider and are reminded to update their child’s immunization records online at immune.wechu.org.
Catch-up immunization clinics are also being offered at the WECHU Windsor and Leamington offices and will continue until the end of March. Families can book an appointment at a WECHU clinic by visiting wechu.org/getimmunized or by calling the WECHU at 519-960-0231.
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