Coronavirus aggressively invades lung cells in chilling new images
The images were published in the New England Journal of Medicine and show how prolific coronavirus can become in a mere four days.
10 September, 2020
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<p>Even cast sterile monochrome, the pictures are spine shivering. At first blush, they appear to depict some unknown fungus devouring a sea anemone or maybe spider egg sacs infesting some poor soul's hair. But the actual subject is far too familiar these days. <a href="https://bigthink.com/tag/coronavirus" target="_self">Those pictures show novel coronavirus</a> in the microscopic flesh.</p><p><a href="https://www.nejm.org/doi/full/10.1056/NEJMicm2023328" target="_blank" rel="noopener noreferrer">Published in the New England Journal of Medicine</a>, the images offer an up-close and far-too-personal look at lung cells teeming with coronavirus. They were produced by Camille Ehre, an assistant professor at the University of School of Medicine's Marsico Lung Institute, and her team. They wanted to research how coronavirus occupied human airways and what happened to the inundated cells. And they vividly got their answer.</p>
Not exactly camera shy
<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzg2MjU2MS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0MDcyMzY5N30.P9-pN3720tOzXNrYTybx3X7qc_7ZO8ZdF15ztj5cgXA/img.jpg?width=1245&coordinates=0%2C52%2C0%2C68&height=700" id="9dbf0" class="rm-shortcode" data-rm-shortcode-id="dd5152d7ead13cca82f0f19be988f538" data-rm-shortcode-name="rebelmouse-image" />Another image of novel coronavirus. This one shows the virions 10 times closer than the above image.
<p>To start, Ehre and her team exposed epithelial cells to novel coronavirus in a biosafe laboratory. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4457445/" target="_blank" rel="noopener noreferrer">Epithelium tissues</a> are found at the barriers between the human body and the outside world, often lining the outer surfaces of organs and blood vessels. They serve many functions, including protection, fluid balance, particle clearance, and triggering immune responses. These functions make them important to the health and safety of our respiratory system.</p><p>The researchers took their epithelial cells from a bronchus, major airway passages by which air moves from the windpipe and into the lungs. The initial cells were taken from a transplanted lung and later grown in lab dishes. So, unlike your typical photoshoot or family portrait, this experiment remained ethically above board.</p><p>After exposing the cells to coronavirus, they waited for the infection to take hold. They then captured images of the epithelial cells with a <a href="https://serc.carleton.edu/research_education/geochemsheets/techniques/SEM.html" target="_blank" rel="noopener noreferrer">scanning electron microscope</a>, a device that uses a focused beam of high-energy electrons to produce images. They discovered a high density of virions—individual particles of the virus existing outside the host cell—had been produced and were swarming over the cells. In a mere 96 hours, virus production skyrocketed to reach a multiplicity of infection of three to one. That means there were three virions for each targeted airway cell.</p><p>"When we looked at these infected cultures under an SEM microscope, the most striking observation was the astonishing number of virions produced by a single infected cell," <a href="https://gizmodo.com/horrifying-images-show-how-the-coronavirus-ravages-our-1844946904" target="_blank" rel="noopener noreferrer">Ehre told Gizmodo in an interview</a>. "Some of these infected cells were so engorged with viruses that they rounded up and detached from the epithelium, giving the impression that they were about to burst."</p><p>The image at the top of this article shows the invasion at one-micrometer magnification. The tentacle-looking projections are <a href="https://medlineplus.gov/ency/imagepages/19533.htm#:~:text=The%20bronchus%20in%20the%20lungs,the%20bronchus%20and%20trap%20microorganisms" target="_blank" rel="noopener noreferrer">respiratory cilia</a>, hair-like organelles on epithelium that move microbes and other debris out of our airways. That spider-web looking stuff is mucus produced by goblet cells; it's used to trap microorganisms and protect the bronchus. Neither are effective against the locust-like plight of virions.</p><p>Above is the same scene but at 100 nanometers (10 times closer). From this all-too intimate vantage, you can clearly see <a href="https://www.oxfordreference.com/view/10.1093/oi/authority.20110803100316752" target="_blank" rel="noopener noreferrer">the peplomers</a>—those spiky protrusions on the virions' envelopes. These peplomers give the coronavirus family its name as they have <a href="https://www.hopkinsmedicine.org/health/conditions-and-diseases/coronavirus" target="_blank" rel="noopener noreferrer">a crown-like appearance</a> when viewed under such a high magnification—<a href="https://www.dictionary.com/browse/corona?s=ts" target="_blank" rel="noopener noreferrer"><em>corona</em></a> coming from the Latin for "garland or crown."</p>Protect your lungs, wash those hands
<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="9626d989ee28bca36e49da0bbbc6c064"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/deJ3nZhK8KI?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p>These images are a stark reminder of why COVID-19 infections can so devastate the human body. It's not only that our bodies serve as their viral birthing centers. It's that we're their all-in-one resource smorgasbord.</p><p>Because <a href="https://www.genome.gov/genetics-glossary/Virus" target="_blank" rel="noopener noreferrer">viruses can't reproduce on their own</a>, they have to inject their genetic material into host cells. They incorporate their DNA or RNA into a host cell's genome, and a bouncing baby virion is born, one that often kills the host upon release. It's basically the backstory of "<a href="https://www.imdb.com/title/tt0090605/?ref_=fn_al_tt_1" target="_blank" rel="noopener noreferrer" style="">Aliens</a>" at a Lilliputian scale, and should viral proliferation spread too quickly, even our immune-responsive Marines can't put up a fight. If enough cells are destroyed, the harm can affect the entire host organism—which now includes us.</p><p>"These images of SARS-CoV-2 infected cultures showing ciliated cells jam-packed with viruses releasing large clumps of virus particles make a strong case for the use of masks by infected and uninfected individuals to limit SARS-CoV-2 transmission," Ehre said.</p><p>They certainly do. Warnings about coronavirus in the abstract can make the case for physical distancing, shuttered schools, and wearing stifling makes while shopping. For a while. But as we've seen, people will eventually tire of their social sacrifices. Perhaps the idea of the above horror show occurring more closely to home will spur us to keep up the fight and listen to the experts for a while longer.</p>
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Chadwick Boseman's death is tragic. Here's what you need to know about colon cancer.
Despite Boseman's young age, this cancer is increasingly common in people under 50.
03 September, 2020
Photo by Gareth Cattermole/Getty Images for Disney
- Though Chadwick Boseman was only 43, rates of cancer in people under 50 have been increasing since 2006.
- African-Americans are 20 percent more likely to get this cancer and 40 percent more likely to die from it than other racial groups.
- Preventive measure include better diet, exercise, regular screenings, and a reduction in smoking and drinking.
<p>The shock of Chadwick Boseman's death continues to reverberate around the world. Boseman's story hit especially hard considering he kept news of the colon cancer that took his life hidden for four years. Beyond his outrageous talent and humanitarian bent, the fact that someone in such great shape was taken out at the age of 43 woke up the entire world about the dangers of colon cancer—which is, in fact, affecting younger demographics every year. </p><h3>What it is</h3><p>Colon cancer forms in the large intestine. This process begins with small, noncancerous polyps. Some of these polyps become colon cancers. Screenings are especially important since polyps do not show symptoms. When identified, they can be removed before turning into a cancer.</p><p>The major types of polyps are adenomas, which are often precancerous; hyperplastic polyps and inflammatory polyps, common polyps that are usually not precancerous; and sessile serrated polyps and traditional serrated adenomas, which carry a high risk of <a href="https://www.cancer.org/cancer/colon-rectal-cancer/about/what-is-colorectal-cancer.html" target="_blank">colorectal cancer</a>. </p><p>Polyps are more likely to contain cancer when larger than one centimeter, more than three are found, and when dysplasia (precancerous cells) is discovered after removal. Cancer first grows in the walls of the colon or rectum after originating in a polyp. If untreated, the cancer can spread to lymph nodes around the body. </p><p>While most colorectal cancers are adenocarcinomas, other types include carcinoid tumors, gastrointestinal stromal tumors, lymphomas, and sarcomas. The exact causes of these cancers are unknown, but lifestyle and environmental factors (listed below) appear to promote colorectal cancers, especially in younger people.</p><h3>Who it affects</h3><p><a href="https://www.cancer.org/cancer/colon-rectal-cancer/about/what-is-colorectal-cancer.html" target="_blank">Colorectal cancer</a>—the collective term for colon cancer and rectal cancer—is the third most common cancer in the world (excluding <a href="https://www.statnews.com/2020/08/31/disparities-kill-king-of-wakanda-chadwick-boseman-changing-landscape-colon-cancer-demographics/" target="_blank">skin cancer</a>). The regions affected are the ascending colon, transverse colon, descending colon, and sigmoid colon. </p><p>Colorectal cancer <a href="https://www.ctpost.com/local/article/No-one-is-immune-Boseman-s-death-shows-15530635.php" target="_blank" rel="noopener noreferrer">affects</a> men and women equally. In 2020, 147,950 people are expected to be diagnosed with colorectal cancer. It is also the second-leading cause of death in America, with an expected 53,000 people dying from it this year. </p><p>Colorectal cancer affects African-Americans particularly hard. They're 20 percent more likely to get this cancer and 40 percent more likely to die from it than any other racial groups. While <a href="https://www.cancer.org/cancer/colon-rectal-cancer/detection-diagnosis-staging/survival-rates.html" target="_blank">90 percent</a> of individuals survive this cancer for five years or more when detected early, only <a href="https://seer.cancer.gov/csr/1975_2017/browse_csr.php?sectionSEL=6&pageSEL=sect_06_table.12" target="_blank">9 percent</a> of Black men survive five years or more when discovered in an advanced stage. </p><p>While age is a factor, that too is changing. In 2001-02, the average age for getting this cancer was 72; 15 years later, it dropped to 66. More disturbingly, the rate of people dying from colorectal cancer in their 40s is increasing. Between 2007-16, there was a 2 percent increase in deaths in this age group <em>every year</em>. <a href="https://coloncancercoalition.org/get-educated/what-you-need-to-know/colon-cancer-facts/" target="_blank">Twenty percent</a> of colorectal cancers are now found in people aged 20-54. This fits with an ongoing trend: an estimated 18,000 Americans under age 50 are expected to be diagnosed with cancer this year. </p>
What is Colorectal Cancer?
<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="42f9d31fe776910c0e2b852fe7f9e89f"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/fW4Y_poPPxg?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><h3>Signs and symptoms</h3><ul><li>An increase in diarrhea or constipation</li><li>Changes in the consistency of stool </li><li>Rectal bleeding</li><li>Constant abdominal discomfort</li><li>Feeling that your bowel never completely empties</li><li>Fatigue or extreme tiredness</li><li>Unexplainable weight loss</li></ul><h3>Risk Factors </h3><ul><li>Old age</li><li>Being African-American</li><li>Having a personal history of polyps or colon cancer</li><li>Inflammatory intestinal conditions</li><li>Inherited syndromes, such as familial adenomatous polyposis (FAP) and Lynch syndrome</li><li>Family history of colorectal cancer</li><li>Radiation therapy during other cancer treatments</li><li>A diet low in fiber and high in fat, aka the "Western diet" </li><li>Increased risk from eating red meat and processed meats</li><li>Sedentary lifestyle</li><li>Diabetes</li><li>Obesity</li><li>Smoking</li><li>Alcohol</li></ul><h3>Interventions</h3><ul><li>A varied diet with lots of fruits, veggies, and whole grains</li><li>Moderate to no alcohol use </li><li>Stop smoking</li><li>Regular exercise</li><li>Maintain a healthy body weight</li><li><a href="https://www.cancer.org/cancer/colon-rectal-cancer/detection-diagnosis-staging/acs-recommendations.html" target="_blank">Regular screenings</a> after the age of 45</li></ul><img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzYyMTA5NC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0MzkyMjg5N30.0HCoYxlY7_3odMVhCwk-97Qky-kY9T5BJsf4XhsXk80/img.jpg?width=1245&coordinates=0%2C47%2C0%2C59&height=700" id="8b343" class="rm-shortcode" data-rm-shortcode-id="7308d48ee92b59ac924d52506afbde12" data-rm-shortcode-name="rebelmouse-image" alt="Chadwick Boseman" />
Actor Chadwick Boseman attends the 2018 MTV Movie And TV Awards at Barker Hangar on June 16, 2018 in Santa Monica, California.
Photo by Emma McIntyre/Getty Images for MTV
<h3>Survivor Stories</h3><p>Sara Stewart is a <a href="https://www.cnn.com/2020/09/02/health/colon-cancer-seriousness-awareness-wellness/index.html" target="_blank">survivor</a> of stage III colon cancer. While all cancers are terrible, she says people are especially unlikely to discuss colon cancer—and that needs to change. Colorectal cancers are predicted to increase by 90 percent by 2030. She advises broader discussions on this topic, an especially important point as she didn't take her own symptoms seriously for two years. Her gastroenterologist discovered a sizable tumor after she finally agreed to a colonoscopy. </p><p>Incredibly, a connection in Hollywood helped her change her perspective on cancer. This connection never told anyone about her own struggle with colon cancer because "she would be blackballed from jobs, written off as unreliable and sickly, even though she continued to work long hours around her treatments." In fact, she lost a big job after someone discovered her cancer. Stewart continues, </p><p style="margin-left: 20px;">"Is it any wonder that Boseman, with his meteoric rise to fame and the responsibility of being one of the preeminent faces of Black empowerment in Hollywood and beyond, didn't share his diagnosis publicly?"</p><p>Fabian Alsultany has worked in the music industry for over a quarter-century, and he did not remain quiet about his struggle with colon cancer 2B—a tumor perforated his colon. A surgery to remove the tumor (and cut out inches of his colon) and six months of chemotherapy <a href="https://riseupeight.org/how-to-succeed-in-music-overcoming-cancer/" target="_blank">left him exhausted</a>.</p><p style="margin-left: 20px;">"My reality was existing in a two-week cycle of death and rebirth. I experienced every side effect in the book: extreme nausea, neuropathy, dizziness, loss of appetite, hair loss, inability to hold any food in…you get the point: it was miserable. I was fortunate to have my family and friends around me through it all."</p><p>Fortunately, Alsultany was able to confide in those around him. He also documented his cancer journey through <a href="http://alsultany32.blogspot.com/" target="_blank">his blog</a>. While he's an outspoken advocate for discussing cancer, not everyone feels safe in this regard. </p><p>Social connections are especially important when struggling with cancer. Hopefully, the ridiculous stigma around cancer, as evidenced in Stewart's writing above, will end with Boseman's death. We need to have these conversations without fear of retribution, and our health care system must make screenings affordable and available to everyone. </p><p>--</p><p><em>Stay in touch with Derek on <a href="http://www.twitter.com/derekberes" target="_blank" rel="noopener noreferrer">Twitter</a>, <a href="https://www.facebook.com/DerekBeresdotcom" target="_blank" rel="noopener noreferrer">Facebook</a> and <a href="https://derekberes.substack.com/" target="_blank" rel="noopener noreferrer">Substack</a>. His next book is</em> "<em>Hero's Dose: The Case For Psychedelics in Ritual and Therapy."</em></p>
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Does warm weather impact COVID-19?
Various studies examine the impact of humidity, temperature, rain, and sunshine on COVID-19.
01 September, 2020
- Researchers around the world have been working to analyze and understand this virus since the global pandemic started earlier this year.
- While the first SARS-CoV virus (2003) did not circulate long enough for researchers to distinguish any specific seasonal pattern, daily weather did have an impact on the number of cases.
- Other studies from China, Australia, Brazil, and the UK take a look at how our weather can impact the transmission of COVID-19.
<p>Many people believe warmer weather protects us from respiratory illnesses - but the reality is that COVID-19 is unlike many of the other respiratory illnesses we've seen. Researchers around the world have been working to analyze and understand this virus since the global pandemic started earlier this year.</p><ul class="ee-ul"></ul>
How does weather impact virus transmission?
<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzU5OTg4OC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyNTU1NjA2MX0.SvtcZz2PxVjC9AFLhC0sRpMDbcFp-RkAPJhuwTsZyWg/img.jpg?width=1245&coordinates=0%2C0%2C100%2C0&height=700" id="e5f2d" class="rm-shortcode" data-rm-shortcode-id="92f1bc5a03e54cc3f2f981acd09d14e2" data-rm-shortcode-name="rebelmouse-image" alt="COVID-19 virus SARS-CoV-2 under microscope weather virus" />How does weather impact the COVID-19 virus?
Image by MIA Studio on Shutterstock
<p><strong>Studies of the first SARS-CoV (in 2003) might help us understand.</strong><br></p><p>While this virus did not circulate long enough for researchers to distinguish any specific seasonal pattern, daily weather did have an impact on the number of cases. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2870397/" target="_blank" rel="noopener noreferrer">According to this study</a>, new cases of SARS-CoV were 18x higher in lower temperatures (under 24.6°C). </p><p><strong>Cold weather impacts your likelihood of getting sick in different ways. </strong></p><p>One factor, according to <a href="https://sciencing.com/cold-weather-affect-immunity-22739.html" target="_blank" rel="noopener noreferrer">Sciencing</a>, that may increase your susceptibility in cold weather is how your sinuses respond to the humidity and temperature changes. Your nose is a natural air filter for your body. When you spend time in cold temperatures, your nasal passages dry out due to the constriction of blood vessels. When you return to warmer temperatures (like coming inside after time spent out in the cold), the sudden influx of moisture can cause your nose to run.</p><p>This usually forces you to breathe through your mouth, robbing you of the filter and making you susceptible to viruses or bacteria in the air. </p><p><strong>Cold weather = more time spent indoors, which can increase the likelihood of transmission.</strong></p><p>Regardless of the weather, it takes exposure to a virus to get a virus. One common reason why virus infections may become more common during cold months is that more people are spending time indoors (and together). </p><p><a href="https://bigthink.com/politics-current-affairs/social-distancing-math" target="_self">As research has determined</a>, social distancing can heavily impact the spread of the COVID-19 virus. Being clustered closer together indoors can increase the likelihood of transmission, giving the effect of the virus spreading faster in the colder months. </p>The weather and COVID-19 studies from around the globe
<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzU5OTg5MC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyNTcwNzgxNH0.t5SY7q3HULHvoWIz5SpPA-DnPHjcgZqa0fANRn8ksxI/img.jpg?width=1245&coordinates=0%2C52%2C0%2C52&height=700" id="fb167" class="rm-shortcode" data-rm-shortcode-id="f3c84c531fb1b51decdb63e5f4a7c516" data-rm-shortcode-name="rebelmouse-image" alt="concept of condensation humidity impact COVID-19 condensation on window" />How do things like humidity, rainfall and sunshine impact the spread of COVID-19?
Photo by matuska on Shutterstock
<p>Laboratory and observational studies of COVID-19 patients have shown there is an impact of humidity on SARS-COV-2.</p><p><strong>Humidity and its impact on COVID-19:</strong></p><p><a href="https://wwwnc.cdc.gov/eid/article/26/9/20-1806_article#r7" target="_blank" rel="noopener noreferrer">A lab-generated aerosol of SARS-CoV-2</a> was stable at a humidity of 53 percent at room temperature (23°C). The virus had not degenerated much, even after 16 hours, and was more robust than SARS-CoV. </p><p>Although laboratory studies cannot be used to explicitly explain how the virus will act in the real world, these findings are very important in deepening our understanding of the virus and its transmission. </p><p><a href="https://www.sciencedirect.com/science/article/pii/S004896972032026X?via%3Dihub" target="_blank" rel="noopener noreferrer">Another study in China</a> (with more than 50 cases of COVID-19) found a link between humidity and reductions in COVID-19 cases. In this simulation, the team measured humidity as absolute humidity (the total amount of water in the air) and found that for every gram per cubic meter in absolute humidity, there was a 67 percent reduction in COVID-19 cases after a lag of 14 days. </p><p>Similar studies (with similar results) have been conducted in <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/tbed.13631" target="_blank" rel="noopener noreferrer">Australia</a>.</p><p><strong>Rainfall and its impact on COVID-19:</strong></p><p>Rainfall may also impact the spread of the virus. <a href="https://www.sciencedirect.com/science/article/pii/S0048969720325146?via%3Dihub" target="_blank" rel="noopener noreferrer">Research out of Brazil</a> looked at rainfall worldwide and confirmed a pattern: for each average inch per day of rain, there was an increase of 56 COVID-19 cases per day. There was no link found between the COVID-19 deaths and rainfall. </p><p><strong>Sunshine and its impact on COVID-19: </strong></p><p>A Spain study found (after 5 days of lockdown) the longer the hours of sunshine, the more cases there were of the virus. This positive association held true with a lag (between sunshine hours and cases) of both 8 and 11 days. </p><p>However, it's important to note that this actually contradicts findings from Influenza research, which suggests a lower transmission with longer hours of sunshine. While influenza and COVID-19 are obviously different, it's interesting to note this contrast, as they are both viral infections.</p><p><strong>While all of these studies are interesting, does it really prove COVID-19 is impacted by weather? </strong></p><p><a href="https://www.medrxiv.org/content/10.1101/2020.05.21.20108803v1" target="_blank" rel="noopener noreferrer">Research out of Oxford</a> actually lists reasons why people should not use these observational studies on the weather and COVID-19 cases to establish if the virus is more or less transmittable based on the season. </p><p>While it's important to note that there are still things we don't know about COVID-19 and that each country has different testing and studying methods, the more we know about how this virus behaves in different climates the more we can work to prevent further infection. </p>
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Study identifies animal species that may be susceptible to coronavirus
On the list of animals at risk are several endangered species.
25 August, 2020
Image source: Jorge Franganillo/Unsplash
- SARS-CoV-2 enters our cells by binding with ACE2 receptors.
- A study finds many animals may provide a similar point of entry for the infection.
- COVID-19 has already been seen in a range of non-humans.
<p>SARS-CoV-2, the novel coronavirus behind COVID-19, has proven to be a dangerously crafty opportunist that in many ways continues to baffle doctors. As of this writing, the official worldwide tally of humans who have died from it stands at <a href="https://www.worldometers.info/coronavirus/?utm_campaign=homeAdvegas1?" target="_blank">nearly 820,000</a>. As if that's not horrifying enough, a new study from <a href="https://www.ucdavis.edu/news/genomic-analysis-reveals-many-animal-species-may-be-vulnerable-sars-cov-2-infection" target="_blank">University of California Davis</a> finds that many other species share the disease's primary receptor. The list includes mammals, amphibians, reptiles, birds, and fish. Already at-risk old world primates and apes are among their number.</p><p>The study is published in <a href="https://www.pnas.org/content/early/2020/08/20/2010146117" target="_blank">Proceedings of the National Academy of Sciences</a>. </p>
ACE2
<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzU4MTgwMC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyMTI3NDU4NH0.BceDb6l6wcwImHgniUPCNX_F5NeJ8vSsrAWNH7DG-x0/img.jpg?width=980" id="2fb6e" class="rm-shortcode" data-rm-shortcode-id="77a7d2b0d83cfc72479f2b9089e512ac" data-rm-shortcode-name="rebelmouse-image" alt="3D illustration of SARS-CoV-2 binding with ACE2 receptors" />3D illustration of SARS-CoV-2 binding with ACE2 receptors
Image source: Kateryna Kon/Shutterstock
<p>SARS-CoV-2's main point of entry into our systems, its main cellular receptor, is an angiotensin converting enzyme-2 known as ACE2. There are many types of cells and tissues in humans that contain ACE2, including the epithelial cells found in the mouth, nose, and lungs. SARS-CoV-2 binds to 25 ACE2 amino acids to get into our cells.</p><p>The researchers investigated the presence of these amino acids in other organisms on the assumption that their presence would provide SARS-CoV-2 entry to their cells as they do in ours. Says first author of the study <a href="https://www.ucdavis.edu/person/articles/27275" target="_blank">Joana Dama</a> of UC Davis, "Animals with all 25 amino acid residues matching the human protein are predicted to be at the highest risk for contracting SARS-CoV-2 via ACE2."</p><p>The precise mechanism by which SARS-CoV-2 infections occur and lead to COVID-19 is still under exploration. Nonetheless, the study operates on the principle that more of the 25 amino acids an animal has, the higher its risk of infection. "The risk is predicted to decrease the more the species' ACE2 binding residues differ from humans," says Dama.</p>Which species are at risk?
<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzU4MTgwMi9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTYwMzA5ODY4Nn0.oZHKdhpvHJjihgp2R3E23hMotY-yazjh0vCw5S_L2F8/img.png?width=980" id="3130d" class="rm-shortcode" data-rm-shortcode-id="8edb6a4f609576554b9067ee019ab08b" data-rm-shortcode-name="rebelmouse-image" alt="species risk chart" />Image source: Matt Verdolivo/UC Davis
<p>Their analysis leads Dama and her co-authors to the conclusion that about 40 percent of the species at risk of SARS-CoV-2 infection are on the International Union for Conservation of Nature's <a href="https://www.iucn.org/resources/conservation-tools/iucn-red-list-threatened-species" target="_blank">"threatened" list</a>.</p><p>Sumatran orangutans, Northern white-cheeked gibbons, and the Western lowland gorillas are all critically endangered and are vulnerable to infection. Some marine animals are also at high risk, including bottlenose dolphins and gray whales.</p><p><span></span>The study asserts that many animals most likely to live among humans are apparently at low risk, including cats, dogs, cattle, sheep, horses, and pigs. Chinese hamsters carry a high risk.</p><p>It's worth noting, however, that there <em>are</em> cases on record of SARS-CoV-2 infections in <a href="https://www.statnews.com/2020/05/13/cats-can-catch-covid-19-from-one-another-study-finds-the-question-is-can-we/" target="_blank">cats</a> and <a href="https://www.aphis.usda.gov/aphis/newsroom/stakeholder-info/sa_by_date/sa-2020/sa-06/sars-cov-2-dog" target="_blank">dogs</a>. <a href="https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciaa325/5811871" target="_blank">Hamsters</a>, too. Less likely house pets like <a href="https://www.aphis.usda.gov/aphis/newsroom/news/sa_by_date/sa-2020/ny-zoo-covid-19" target="_blank" rel="noopener noreferrer dofollow">lions, tigers</a>, and <a href="https://www.npr.org/sections/goatsandsoda/2020/06/25/882095588/dutch-minks-contract-covid-19-and-appear-to-infect-humans" target="_blank">mink</a> have also been infected.</p><p>Bats, the presumed <a href="https://www.nature.com/articles/s41586-020-2012-7" target="_blank" rel="noopener noreferrer dofollow">source of SARS-CoV-2</a>, are found by the study to be at very low risk of infection due to a lack of ACE2 receptors. Other experimental data lines up with the study's finding, which suggests that spread of SARS-CoV-2 from bats is likely to have involved intermediate hosts en route to infecting humans.</p><p>The authors have made available for <a href="https://www.pnas.org/highwire/filestream/945399/field_highwire_adjunct_files/1/pnas.2010146117.sd01.xlsx" target="_blank">download</a> the full list of animals its authors find may be susceptible to SARS-CoV-2 infection.</p>Animal exposure to SARS-CoV-2
<p>Lead author Harris Lewin explains the importance of the research:</p><p>"The data provide an important starting point for identifying vulnerable and threatened animal populations at risk of SARS-CoV-2 infection. We hope it inspires practices that protect both animal and human health during the pandemic."</p><p>The study finds the same 40 percent of animals may also be especially likely to encounter the infection through human contact. The main locus of such interaction cited by the study is zoos. (Both the <a href="https://nationalzoo.si.edu/animals/news/covid-19-update" target="_blank">National Zoo</a> and the <a href="https://zoo.sandiegozoo.org/videos?playlistVideoId=6151893073001" target="_blank" rel="noopener noreferrer dofollow">San Diego Zoo</a> contributed genetic material to the researchers for the study.)</p><p>Co-author Klaus-Peter Koepfli of the Smithsonian-Mason School of Conservation explains that zoo personnel already guard against such transmissions, saying, "Zoonotic diseases and how to prevent human to animal transmission is not a new challenge to zoos and animal care professionals." The study makes keeping animals and humans apart at zoos more urgent than ever, though, and "this new information allows us to focus our efforts and plan accordingly to keep animals and humans safe."</p>
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COVID-19 symptoms appear in a specific order, study finds
One reason to suspect you have COVID-19 may be the order in which the symptoms appear.
21 August, 2020
Image source: Pormezz/Shutterstock
- USC researchers identify a distinct order in which COVID-19 symptoms present themselves.
- SARS-CoV-2 affects the digestive tract in a way that distinguishes it from other similar infections.
- If you experience these symptoms in this order, call your doctor.
<p>One of the scary things about COVID-19 is that the early symptoms it presents are also common indicators of a flu or infection: fever, cough, and so on. When a person experiences any of these symptoms these days, it's reasonable to wonder if they have COVID-19.</p><p>Now researchers from the <a href="https://kuhn.usc.edu/people/" target="_blank">Kuhn Lab</a> as University of Southern California have discovered something that may be useful for anyone questioning whether they've been infected with COVID-19. According to their investigation, <a href="https://news.usc.edu/174346/covid-19-symptoms-usc-research-fever-cough/" target="_blank" rel="noopener noreferrer dofollow">it's likely that coronavirus symptoms present in a particular order</a>. This is unusual — other illness that produces these symptoms don't follow any known sequence — and if a person gets these symptoms in this particular order, they should self-isolate and get tested.</p><p>The study is published in <a href="https://www.frontiersin.org/articles/10.3389/fpubh.2020.00473/full" target="_blank">Frontiers in Public Health</a>.</p>
The symptoms in order
<p>The USC team says that coronavirus' symptoms present in this order:</p><ol><li>fever</li><li>cough and muscle pain</li><li>nausea and/or vomiting</li><li>diarrhea</li></ol><p>What really sets apart COVID-19 from other diseases is the timing of the nausea/vomiting and diarrhea. While the respiratory symptoms are similar to those associated with Middle East respiratory syndrome (MERS) and severe acute respiratory syndrome (SARS), the gastrointestinal sequence of COVID-19 is distinctive. COVID-19 attacks the upper GI tract first, causing nausea/vomiting before moving down to the lower GI tract, producing diarrhea. This is the opposite of the way in which these symptoms appear with MERS and SARS.</p><p>"This order is especially important to know when we have overlapping cycles of illnesses like the flu that coincide with infections of COVID-19, says study co-author Peter Kuhn. "Doctors can determine what steps to take to care for the patient, and they may prevent the patient's condition from worsening."</p><p>The study calls for further investigation into the presenting symptoms of COVID-19, since unanswered questions remain. Might the order of symptoms vary with outlier strains of SARS-CoV-2? Do other risk factors such as obesity, or environmental factors such as temperature affect their order?</p><img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzU3MzgyOC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyMzU4MTYzOH0.OB7tF_mF_grw-81Mq1ETBzOP6UWJMtpqwm30MjDf-c8/img.jpg?width=980" id="af33e" class="rm-shortcode" data-rm-shortcode-id="9c94a7be3f9f5659b1de411db2429bea" data-rm-shortcode-name="rebelmouse-image" alt="man grimacing from illness" />Image source: fizkes/Shutterstock
Clue in the data
<p>The core data set used by the USC team were case histories of 55,000 people who contracted COVID-19 in China. The data was collected by the World Health Organization from February 16-24, 2020. Their analysis was supplemented by data from almost 1,100 additional cases documented by the China Medical Treatment Expert Group via the National Health Commission of China — these came from December 11, 2019 to January 29, 2020.</p><p>To assess the similarity of COVID-19's symptom ordering to the flu, the researchers looked at the data from 2,470 North American, European, and Southern Hemisphere flu cases from 1994 to 1998.</p>Early diagnosis
<p style="margin-left: 20px;"><em>"The importance of knowing first symptoms is rooted in the need to stop the spread of COVID-19, a disease that is two to three times more transmissible than influenza and results in outbreaks of clusters.' — Larsen, et al</em></p><p>Lead study author Joseph Larsen says that in addition to slowing transmission, an understanding of COVID-19's progression could also facilitate more effective treatment. </p><p>"The order of the symptoms matter. Knowing that each illness progresses differently means that doctors can identify sooner whether someone likely has COVID-19, or another illness, which can help them make better treatment decisions," says Larsen, who adds, "Given that there are now better approaches to treatments for COVID-19, identifying patients earlier could reduce hospitalization time."</p>
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