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Persisting coronavirus could drag out COVID-19 symptoms – National Geographic

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Most COVID-19 patients recover from their acute infection within two weeks, but bits of the virus don’t always disappear from patients’ bodies immediately. Now a new study, one of the largest focusing on hospitalized COVID-19 patients, shows that some patients harbor these viral remnants for weeks to months after their primary COVID-19 symptoms resolve.

The study suggests that when the genetic material of the virus, called RNA, lingers in the body longer than 14 days, patients may face worse disease outcomes, experience delirium, stay longer in the hospital, and have a higher risk of dying from COVID-19 compared with those who cleared the virus rapidly. The persistence of the virus may also play a role in long COVID, the debilitating suite of symptoms that can last for months. Estimates suggest between 7.7 and 23 million people in the United States alone are now affected by long COVID.

Without immunity from vaccination or a previous infection, SARS-CoV-2—the virus that causes COVID-19—replicates and spreads throughout the body and is shed through the nose, mouth, and gut. But for most infected people, virus levels in the body peak between three and six days after the original infection, and the immune system clears the pathogen within 10 days. The virus shed after this period is generally not infectious.

Even after accounting for disease severity, whether the patients were intubated, or had underlying medical comorbidities, “there is something here that signals that patients who are persistently PCR positive have worse outcomes,” says Ayush Batra, a neurologist at Northwestern University Feinberg School of Medicine, who led the new study.

Batra’s study shows that patients who had prolonged shedding during an acute infection risk more severe outcomes from COVID-19, says Timothy Henrich, a virologist and immunologist at the University of California, San Francisco who was not involved in the new research. But the study doesn’t investigate whether this persistent virus is directly responsible for long COVID.

“There are multiple leading hypotheses out there about the cause of long COVID, including viral persistence, and it may be that there are multiple pathways at play, perhaps to some varying degree in any one person,” says Linda Geng, a doctor at Stanford Health Care who co-directs a newly opened Post-Acute COVID-19 Syndrome Clinic for treating long COVID sufferers.

Persisting virus causes worse COVID-19 outcomes

Batra and his team began studying persistent coronavirus infections after observing that some patients who were returning to the hospital were still testing positive for the virus four or five weeks after they were diagnosed with the initial infection.

For their new study, the team analyzed 2,518 COVID-19 patients hospitalized in the Northwestern Medicine Healthcare system between March and August 2020. They focused on PCR tests, which are considered the gold standard, because such tests detect genetic material from the virus and so are highly sensitive and less likely to return false negatives.

The team found that 42 percent of patients continued to test PCR positive two weeks or longer after their initial diagnosis. After more than 90 days, 12 percent of the persistent shedders were still testing positive; one person tested positive 269 days after the original infection.

Viral persistence has been noted before in previous smaller studies. Researchers showed that even patients without obvious COVID-19 symptoms harbored SARS-CoV-2 for a couple of months and beyond. In some immunocompromised patients, the virus may not be cleared for a year. Four percent of COVID-19 patients in a trial on chronic COVID-19 infection at Stanford continued to shed viral RNA in feces seven months after diagnosis. However, Batra’s study illustrates that a larger number of patients take longer to clear the virus than previously realized.

“Persistent RNA shedding would mean that there still is a reservoir of virus somewhere in the body,” says Michael VanElzakker, a neuroscientist affiliated with Massachusetts General Hospital, Harvard Medical School and Tufts University. Such reservoirs are thought to allow the virus to persist over a long period of time and could trigger the immune system to act aberrantly, perhaps causing long COVID.

“Some patients, for variety of reasons, are not able to clear this reservoir, or their immune system reacts in some abnormal way that results in these persistent symptoms that have come to be termed as long COVID,” says Batra.

Still, many scientists don’t think there is sufficient evidence yet to link the persistence of viral RNA to long COVID.

Sleeping viruses

The list of human tissues where SARS-CoV-2 hides long after the initial infection is growing. Studies have identified the virus, or genetic material from it, in the intestines of patients four months after initial infection, and inside the lung of a deceased donor more than a hundred days after recovery from COVID-19. One study that’s not yet peer reviewed also detected the virus in the appendix and breast tissues 175 and 462 days, respectively, after coronavirus infections. And research from the U.S. National Institutes of Health that’s also not yet peer reviewed detected SARS-CoV-2 RNA persisting at low levels across multiple tissues for more than seven months, even when it was undetectable in blood.

“It is not surprising to find viruses encountered during the lifetime” surviving in human tissues, says Kei Sato, a virologist at the University of Tokyo. Indeed, Sato’s work has shown that humans frequently accumulate viruses such as Epstein-Barr virus, varicella zoster virus (which causes chicken pox), and many herpes viruses in dormant forms. These persisting viruses are typically present at low levels, so only extensive genetic sequencing can identify them.

This highlights how complicated it is to prove or disprove the association between persisting SARS-CoV-2 and long COVID. Shingles, for example, occurs decades after a chickenpox infection, when the latent virus gets reactivated during immune stress.

Likewise, lingering SARS-CoV-2 could cause long-term health problems. Henrich thinks when the virus is seeded in deep tissues, it potentially causes the immune system to shift into a dysregulated inflammatory state. Such a state is “probably evidence that the virus is capable of persisting, and maybe getting down into sort of an uneasy truce with the body,” says VanElzakker.

Still, associating any lingering virus with long COVID will require extensive studies. “We still don’t know enough to make strong conclusions about any of the current proposed mechanisms, but research is actively underway to answer those questions,” says Geng.

Clearing up persistent virus might cure long COVID 

Both Geng and Henrich’s groups have reported preliminary case studies that show an improvement in long COVID symptoms after patients were treated with Pfizer’s COVID-19 oral antiviral Paxlovid. Paxlovid stops the virus from replicating, which is why some experts think it can clear any lingering virus. But both authors urge caution before assuming that Paxlovid will be safe, effective, or sufficient and thereby a reliable cure for long COVID.

“There are some interesting hypotheses about how Paxlovid may be useful in the treatment of long COVID, but we’d need further investigation and clinical trials before coming to any conclusions,” says Geng.

The U.S. Food and Drug Administration has warned against off-label uses of Paxlovid, which is not approved for long COVID treatment. The agency has given Paxlovid an emergency use authorization to treat mild to moderate COVID-19 in those who are at risk of developing severe disease, twice daily for five days soon after a positive test.

“It would be important to consider the optimal duration of treatment [of Paxlovid] to ensure long-term and sustained results,” says Geng.

President Joe Biden has directed the secretary of Health and Human Services to create a national action plan on long COVID, and the NIH has launched a multi-year study called RECOVER to understand, prevent, and treat long-term health effects related to COVID-19.

In the meantime, vaccines not only continue to protect against severe disease, but evidence is also emerging that they can prevent many long COVID symptoms. One new study compared 1.5 million unvaccinated COVID-19 patients to 25,225 vaccinated patients with breakthrough infections, and it found that vaccines significantly reduced the risk of developing long COVID symptoms 28 days after an infection. The protective effect of vaccination got even larger at 90 days post-infection.

“Although a majority of people do not develop long COVID, it’s certainly a risk, and COVID doesn’t stop after the first 10 days of becoming infected,” says Henrich. “For those who don’t take COVID seriously, it can be life changing.”

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Women in states with bans are getting abortions at similar rates as under Roe, report says

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Women living in states with abortion bans obtained the procedure in the second half of 2023 at about the same rate as before the U.S. Supreme Court overturned Roe v. Wade, according to a report released Tuesday.

Women did so by traveling out of state or by having prescription abortion pills mailed to them, according to the #WeCount report from the Society of Family Planning, which advocates for abortion access. They increasingly used telehealth, the report found, as medical providers in states with laws intended to protection them from prosecution in other states used online appointments to prescribe abortion pills.

“The abortion bans are not eliminating the need for abortion,” said Ushma Upadhyay, a University of California, San Francisco public health social scientist and a co-chair of the #WeCount survey. “People are jumping over these hurdles because they have to.”

Abortion patterns have shifted

The #WeCount report began surveying abortion providers across the country monthly just before Roe was overturned, creating a snapshot of abortion trends. In some states, a portion of the data is estimated. The effort makes data public with less than a six-month lag, giving a picture of trends far faster than the U.S. Centers for Disease Control and Prevention, whose most recent annual report covers abortion in 2021.

The report has chronicled quick shifts since the Supreme Court’s Dobbs v. Jackson Women’s Health Organization ruling that ended the national right to abortion and opened the door to enforcement of state bans.

The number of abortions in states with bans at all stages of pregnancy fell to near zero. It also plummeted in states where bans kick in around six weeks of pregnancy, which is before many women know they’re pregnant.

But the nationwide total has been about the same or above the level from before the ruling. The study estimates 99,000 abortions occurred each month in the first half of 2024, up from the 81,000 monthly from April through December 2022 and 88,000 in 2023.

One reason is telehealth, which got a boost when some Democratic-controlled states last year began implementing laws to protect prescribers. In April 2022, about 1 in 25 abortions were from pills prescribed via telehealth, the report found. In June 2024, it was 1 in 5.

The newest report is the first time #WeCount has broken down state-by-state numbers for abortion pill prescriptions. About half the telehealth abortion pill prescriptions now go to patients in states with abortion bans or restrictions on telehealth abortion prescriptions.

In the second half of last year, the pills were sent to about 2,800 women each month in Texas, more than 1,500 in Mississippi and nearly 800 in Missouri, for instance.

Travel is still the main means of access for women in states with bans

Data from another group, the Guttmacher Institute, shows that women in states with bans still rely mostly on travel to get abortions.

By combining results of the two surveys and comparing them with Guttmacher’s counts of in-person abortions from 2020, #WeCount found women in states with bans throughout pregnancy were getting abortions in similar numbers as they were in 2020. The numbers do not account for pills obtained from outside the medical system in the earlier period, when those prescriptions most often came from abroad. They also do not tally people who received pills but did not use them.

West Virginia women, for example, obtained nearly 220 abortions monthly in the second half of 2023, mostly by traveling — more than in 2020, when they received about 140 a month. For Louisiana residents, the monthly abortion numbers were about the same, with just under 700 from July through December 2023, mostly through shield laws, and 635 in 2020. However, Oklahoma residents obtained fewer abortions in 2023, with the monthly number falling to under 470 from about 690 in 2020.

Telehealth providers emerged quickly

One of the major providers of the telehealth pills is the Massachusetts Abortion Access Project. Cofounder Angel Foster said the group prescribed to about 500 patients a month, mostly in states with bans, from its September 2023 launch through last month.

The group charged $250 per person while allowing people to pay less if they couldn’t afford that. Starting this month, with the help of grant funding that pays operating costs, it’s trying a different approach: Setting the price at $5 but letting patients know they’d appreciate more for those who can pay it. Foster said the group is on track to provide 1,500 to 2,000 abortions monthly with the new model.

Foster called the Supreme Court’s 2020 decision “a human rights and social justice catastrophe” while also saying that “there’s an irony in what’s happened in the post-Dobbs landscape.”

“In some places abortion care is more accessible and affordable than it was,” she said.

There have no major legal challenges of shield laws so far, but abortion opponents have tried to get one of the main pills removed from the market. Earlier this year, the U.S. Supreme Court unanimously preserved access to the drug, mifepristone, while finding that a group of anti-abortion doctors and organizations did not have the legal right to challenge the 2000 federal approval of the drug.

This month, three states asked a judge for permission to file a lawsuit aimed at rolling back federal decisions that allowed easier access to the pill — including through telehealth.

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How many smoke-related deaths from wildfires are linked to climate change every year?

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Climate change may be contributing to thousands more wildfire smoke-related deaths every year than in previous decades, a new study suggests — results a Canadian co-author says underline the urgency of reducing planet-warming emissions.

The international study published Monday is one of the most rigorous yet in determining just how much climate change can be linked to wildfire smoke deaths around the world, said Sian Kou-Giesbrecht, an assistant professor at Dalhousie University.

“What stands out to me is that this proportion is increasing just so much. I think that it really kind of attests to just how much we need to take targeted action to reducing greenhouse-gas emissions,” she said in an interview.

The study estimates, using mathematical modeling, that about 12,566 annual wildfire smoke-related deaths in the 2010s were linked to climate change, up from about 669 in the 1960s, when far less carbon dioxide was concentrated in the atmosphere.

Translated to a proportion of wildfire smoke mortality overall, the study estimates about 13 per cent of estimated excessdeaths in the 2010s were linked to climate change, compared to about 1.2 per cent in the 1960s.

“Adapting to the critical health impacts of fires is required,” read the study, published in the peer-reviewed journal Nature Climate Change.

While wildfires are a natural part of the boreal forest ecosystem, a growing number of studies have documented how climate change, driven by the burning of fossil fuels, is making them larger and more intense — and contributing more to air pollution.

The same research group is behind another study published in the same journal Monday that suggests climate change increased the global area burned by wildfire by about 16 per cent from 2003 to 2019.

Those climate-fuelled fires then churn out more fine particle pollution, known as PM2.5, that’s tiny enough to get deep into the lungs — and in the long run can have serious health effects.

The study that estimated the scale of those effects is based on modeling, not historical data about reported deaths from air pollution.

Researchers used established public-health metrics for when pollution is thought to contribute to mortality, then figured out the extent to which wildfire smoke may have played a role in that overall exposure to arrive at the estimates.

Meanwhile, Health Canada estimates that between 2013 and 2018, up to 240 Canadians died every year due to short-term exposure to wildfire air pollution.

Kou-Giesbrecht said Monday’s study did not find that climate change had a major influence on the number of smoke-related deaths from Canada’s boreal wildfires.

She suggested that’s likely due to the country’s relatively small population size, and how tricky it is to model forest fires in the region, given its unique mix of shrubs and peat.

But she also noted that a stretch of devastating Canadian wildfire seasons over the past several years was not captured in the study, and she expects future research could find a bigger increase in deaths and public-health problems linked to climate change.

The most affected regions in the study were South America, Australia and Europe.

Kou-Giesbrecht said the more studies that uncover the link between climate change and disasters as “tangible” as wildfires, the more the case for “drastic climate action” will be bolstered.

“I think that the more and more evidence that we have to support the role of climate change in shaping the past 100 years, and knowing that it will continue to shape the next 100 years, is really important,” she said.

“And I find that personally interesting, albeit scary.”

The study used three highly complex models to estimate the relationship between climate change, land use and fire.

The models, which each contain thousands upon thousands of equations, compare what wildfires look like in the current climate to what they may have looked like in pre-industrial times, before humans started to burn vast amounts of fossil fuels.

The researchers used the models to calculate gas and aerosol emissions from wildfires between 1960 and 2019, and then make estimates about annual smoke-related deaths.

The type of methodology used by Monday’s studies, known as attribution science, is considered one of the fastest-growing fields of climate science. It is bolstered in part by major strides in computing power.

This report by The Canadian Press was first published Oct. 21, 2024.

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Some Ontario docs now offering RSV shot to infants with Quebec rollout set for Nov.

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Some Ontario doctors have started offering a free shot that can protect babies from respiratory syncytial virus while Quebec will begin its immunization program next month.

The new shot called Nirsevimab gives babies antibodies that provide passive immunity to RSV, a major cause of serious lower respiratory tract infections for infants and seniors, which can cause bronchiolitis or pneumonia.

Ontario’s ministry of health says the shot is already available at some doctor’s offices in Ontario with the province’s remaining supply set to arrive by the end of the month.

Quebec will begin administering the shots on Nov. 4 to babies born in hospitals and delivery centers.

Parents in Quebec with babies under six months or those who are older but more vulnerable to infection can also book immunization appointments online.

The injection will be available in Nunavut and Yukon this fall and winter, though administration start dates have not yet been announced.

This report by The Canadian Press was first published Oct. 21, 2024.

-With files from Nicole Ireland

Canadian Press health coverage receives support through a partnership with the Canadian Medical Association. CP is solely responsible for this content.

The Canadian Press. All rights reserved.

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