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Covid-19 origins: Earliest cases in humans point to Wuhan market as the source of the coronavirus

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A fresh look at what we know about the first covid-19 cases shows that the earliest known instance was in a person who worked at the Huanan market in Wuhan, which was suspected as the source from the start of the pandemic



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18 November 2021

A sign pointing to the Huanan market in Wuhan, China, where people may have been infected with the coronavirus in the early stages of the covid-19 pandemic

BJ Warnick/Newscom/Alamy

An analysis of what we know about the earliest covid-19 cases has strengthened the argument that the coronavirus pandemic began when animals at the Huanan market in Wuhan, China, passed the virus on to people. Among other things, it concludes that the first case was a woman who worked as a seafood vendor at the market, who became ill on 11 December 2019.

It is clear that the SARS-CoV-2 virus derives from bat coronaviruses. What isn’t clear is where, when and how it got from bats into people. It has been suspected right from the start that live animals at the Huanan market might be the intermediate host, as the initial cases were clustered around this site.

A World Health Organization report on the origins of SARS-CoV-2, published earlier this year, states that the first person known to have covid-19 became ill on 8 December and had no connection to the market. This was partly why the report concluded that no firm conclusion about the role of the market could be drawn.

However, this man – a 41-year-old accountant living 30 kilometres away from the market – went to hospital on 8 December because of dental problems and only developed covid-19 symptoms on 16 December, says Michael Worobey at the University of Arizona in his analysis.

These dates are confirmed by media interviews with the accountant, hospital records and a scientific paper, Worobey says. That means that the earliest known cases were indeed linked to the market, with the first being the seafood vendor who became ill on 11 December.

Why this isn’t in the WHO report is unclear, as the team did speak to the accountant. “My guess is that they were told that this was the ‘December 8’ patient and just accepted it as read,” Worobey says. “But it would be interesting to learn more about that interview, for sure.”

When asked if their report had got it wrong, a WHO spokesperson said it was difficult to comment on particular cases. “The team did meet with some early patients, but those were not epidemiological interviews collecting health data that would put them in the timeline,” the spokesperson told New Scientist. “Those interviews were done by Chinese authorities in 2020.”

Overall, according to the WHO report, a third of 168 retrospectively identified cases in December had links to the Huanan market. This is in line with what one would expect if the market was the source, Worobey says. Because the original SARS-CoV-2 virus was highly infectious and could spread asymptomatically, many cases would soon lack a direct link to the source.

However, it has been suggested that this apparently strong link to the market is due to bias, because once authorities were alerted on 29 December, they specifically began looking for cases linked to the market.

Worobey says this can be checked by looking at what happened at the three hospitals where doctors first realised something was amiss. They had identified 19 unexplained pneumonia cases, of which 10 were linked to the market, before higher authorities were alerted.

“There was a genuine preponderance of early covid-19 cases associated with Huanan market,” he writes.

What’s more, not only are many early cases linked to the market, they are specifically linked to the western part of the market where live animals such as raccoon dogs were housed. Raccoon dogs are a potential intermediate host – they can be infected by SARS-CoV-2, but display few symptoms.

“Combined, this is compelling evidence that covid-19 has a live-animal-associated market origin much like the first SARS virus,” says David Robertson at the University of Glasgow, UK. “Whether the initial transmissions were from animals to customers in the market, via vendors or both is hard to say.”

Not everyone agrees. “There is nothing new in this article which could make a natural origin of SARS-CoV-2 more likely than a laboratory one,” says Rossana Segreto at the University of Innsbruck in Austria.

But other recent findings have weakened the case for a lab origin, which some researchers say was never strong. In particular, coronaviruses that are the closest match yet found to SARS-CoV-2 have been discovered in bats in Laos. These wild viruses have features in common with SARS-CoV-2 that some had claimed could only have arisen in a lab during so-called gain-of-function experiments, showing these features can and do evolve in the wild.

Journal reference: Science, DOI: 10.1126/science.abm4454

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Solar storms may cause up to 5500 heart-related deaths in a given year

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In an approximate 11-year cycle, the sun blasts out charged particles and magnetised plasma that can distort Earth’s magnetic field, which may disrupt our body clock and ultimately affect our heart



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17 June 2022

A solar storm

Jurik Peter/Shutterstock

Solar storms that disrupt Earth’s magnetic field may cause up to 5500 heart-related deaths in the US in a given year.

The sun goes through cycles of high and low activity that repeat approximately every 11 years. During periods of high activity, it blasts out charged particles and magnetised plasma that can distort Earth’s magnetic field.

These so-called solar storms can cause glitches in our power grids and bring down Earth-orbiting satellites. A handful of studies have also hinted that they increase the risk of …

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UK Covid infection rate rising, with more than a million cases in England | Coronavirus

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Coronavirus infections are rising in the UK, figures have revealed, with experts noting the increase is probably down to the more transmissible BA.4 and BA.5 Omicron variants.

The figures from the Office for National Statistics (ONS), based on swabs collected from randomly selected households, reveal that in the week ending 11 June an estimated one in 50 people in the community in England are thought to have had Covid – around 1.13 million people.

The figure is even higher, at one in 45, in both Wales and Northern Ireland, while it was highest in Scotland where, in the week ending 10 June, one in 30 people are thought to have been infected.

While the figures remain below the peak levels of infection seen earlier this year, when around one in 13 people in England had Covid, the findings are a rise on the previous week where one in 70 people in England were thought to be infected. Furthermore, the data reveals increases in all regions of England, except the north-east, and across all age groups.

Experts say that a key factor in the increase is probably the rise of the Covid variants of concern BA.4 and BA.5.

“Infections have increased across all four UK nations, driven by rising numbers of people infected with the BA.4 and BA.5 Omicron variants,” said Kara Steel, senior statistician for the Covid-19 Infection Survey.

While Steel said it remained too early to say if this was the start of another wave, others have warned it may already have begun, with increased mixing and travelling among other factors fuelling a rise in cases.

Among concerns scientists have raised are that BA.4, BA.5 and another variant on the rise, BA.2.12.1, replicate more efficiently in human lung cells than BA.2.

Prof Azra Ghani, an epidemiologist at Imperial College London, said the latest figures were not surprising, and might rise further.

“This increase in infection prevalence is likely due to the growth of the BA.4 and BA.5 Omicron subvariants, which as we have seen elsewhere in Europe, appear to be able to escape immunity generated from previous Omicron subvariants,” she said.

“It is therefore possible that we will continue to see some growth in infection prevalence in the coming weeks and consequently an increase in hospitalisations, although these subvariants do not currently appear to result in any significantly changed severity profile. This does however serve as a reminder that the Covid-19 pandemic is not over.”

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NHS to offer women in England drug that cuts recurrence of breast cancer | Breast cancer

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Thousands of women in England with breast cancer are to benefit from a new pill on the NHS which reduces the risk of the disease coming back.

The National Institute for Health and Care Excellence (Nice) has given the green light to abemaciclib, which cuts the chance of breast cancer returning after a patient has had surgery to remove a tumour.

Trials showed that patients who had the drug with hormone therapy had a more than 30% improved chance of their cancer not coming back after surgery, compared with hormone therapy alone.

“It’s fantastic thousands of women with this type of primary breast cancer will now have an additional treatment option available on the NHS to help further reduce the risk of the disease coming back,” said Delyth Morgan, the chief executive of charity Breast Cancer Now.

“The fear of breast cancer returning or spreading to other parts of their body and becoming incurable can cause considerable anxiety for so many women and their loved ones.

“New effective treatments such as abemaciclib, which can offer more women the chance to further reduce the risk of the disease recurring, are therefore extremely welcome and this is an important step change in the drug options available for this group of patients.”

The twice-a-day pill is suitable for women with hormone receptor-positive, HER2-negative, node-positive early breast cancer at high risk of recurrence who have had surgery. About 4,000 women will benefit initially, Nice said.

Helen Knight, the interim director of medicines evaluation at Nice, said the draft recommendation came less than a month after abemaciclib received its licence.

“The fact that we have been able to produce draft recommendations so quickly is testament to the success of our ambition to support patient access to clinically and cost effective treatments as early as possible,” said Knight. “Until now there have been no targeted treatments for people with this type of breast cancer.

“Abemaciclib with hormone therapy represents a significant improvement in how it is treated because being able to have a targeted treatment earlier after surgery will increase the chance of curing the disease and reduce the likelihood of developing incurable advanced disease.”

Abemaciclib works by targeting and inhibiting proteins in cancer cells which allow the cancer to divide and grow. It normally costs £2,950 for a packet of 56 150mg-tablets, but the manufacturer, Eli Lilly, has agreed an undisclosed discounted price for NHS England.

“Thanks in part to this latest deal struck by NHS England, NHS patients will be able to access another new targeted drug for a common and aggressive form of breast cancer,” said Prof Peter Johnson, the cancer director of NHS England.

“Abemaciclib, when used alongside a hormone therapy, offers a new, doubly targeted, treatment option, helping to increase the chances of beating the cancer for good, as well as meeting the NHS’s commitment to delivering improved cancer care under our long-term plan.”

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