Dear Reader:

Glossary, continued:

Human Viral Immunity: the ability of a human body to resist a harmful virus from entering and multiplying in it.

Active Immunity: happens in one of the following ways: (1) Naturally, when an infected individual produces antibodies for the infecting virus. After recovery, the body remembers the virus, and when encountering it again, it produces the same antibodies as before, or (2) Artificially, when an uninfected individual is vaccinated, that is: a weak form of the virus  is artificially introduced to the body, the body reacts by producing antibodies for that virus. In the future, when encountering the same virus (a stronger version of it), the body will produce the same antibodies as it did following vaccination.

Passive Immunity(also called passive antibody therapy): antibodies from an immune person are transferred to a non-immune person via blood transfusion. The body of the receiver does not develop memory for the antibodies it passively receives, so the person is at risk of being infected by the same virus at a later time. It is a short term immunization.

Herd Immunity (also called population immunity, or social immunity): occurs when a large percentage of a population has become immune to an infection either by having been infected and  recovered from the infection before, producing antibodies as a result, or by being vaccinated. Individuals who are vulnerable to the infection, that is, not immune to it, are protected from the virus by being surrounded by people who are immune.

Viral vaccine (simplified): a weak form of a virus artificially introduced to an uninfected individual so to stimulate the body to produce antibodies for the virus, the body then remembers the virus/ antibodies, and will produce the same antibodies if and when it encounter that virus again. A vaccine can be specific to a particular virus or non specific.

Non-specific vaccine: a vaccine that protects an individual from more than one virus. For example, the BCG vaccine was developed against tuberculosis but has shown to protect individuals against respiratory infection.

Antiviral drugs/ medications: medications that don’t destroy the virus, but inhibit the virus’s development, so that the infected person experiences less severe symptoms and a shorter duration of symptoms. Most antiviral medications are specific to a particular virus, and some are broad spectrum, that is, they treat a variety of viruses.

Flattening the curve: lowering the number of new infections per day, so that there is a spreading out of new infections over a long period of time. That way, fewer new patients need hospitalization per day, and hospitals are able to handle the lesser influx of new patients (instead of being overwhelmed by a spike of new patients, not having enough beds, equipment, staff and services to handle the spike). The flattening of the curve is achieved by social distancing and hygiene practices.

Worldometer: a reference website that provides real time statistics for such things as world population, economics and health. It is owned and operated by data company Dadax which generates revenue through online advertising. It is part of the Real Time Statistics Project, and is managed by an international team of developers, researchers, and volunteers. In 2011, it was voted as one of the best free reference websites by the American Library Association. In early 2020, the website gained popularity during the Covid-19 pandemic.

Wikipedia: a multilingual online encyclopedia, the largest and most popular general reference work on the World Wide Web. It features exclusively free content and no commercial ads, and is owned and supported by the Wikimedia Foundation, a non profit organization funded primarily through donations. Originated in the US in English, it is now available in 285 languages. The English Wikipedia has almost 40 million registered editors, and over 144,000 active editors. Jimmy Wales (one of the two creators of the site) said that “over 50% of all the edits are done by just 0.7% of the users.. 524 people.. And in fact, the most active 2%, which is 1400 people, have done 73.4% of all the edits”.

(I used Wordometer and Wikipedia in my previous threads and will use these resources again).

anita

• This reply was modified 4 years, 7 months ago by .

Dear Reader:

Viruses are by far the most abundant biological entities on Earth. They infect fungi, bacteria, plants and animals. Viruses that infect plants are harmless to animals, and most viruses that infect other animals are harmless to humans.

Some viruses infect one species only (being species-specific, having a narrow host range), for example, the smallpox virus infects only humans. Other viruses infect a few or many species (having a broad host range), for example, the rabies virus infects bats, coyotes, horses, monkeys, rabbits, skunks, racoons, foxes, wolves, cattle, cats, dogs and humans.

Zoonotic viruses are viruses that originated in other animals and transitioned from that other animal to humans through insect  bites, animal bites, contact with feces and bodily fluids (mucus, saliva, blood, urine, semen), and inhaling (respiratory transmission).

Viral populations don’t grow through cell divisions because they are not cells. They grow by using the host cell’s mechanism to multiply. First a virus attaches itself to the host by its surface protein binding to a specific receptor on the outside of the host’s cell. The virus then fuses with the host’s  cellular membrane (or gets taken in by the host’s cell), and the virus finds itself inside the host’s cell. A virus is made of genetic material (DNA or RNA) surrounded by a protein shell called capsid. As the virus enters the host cell, it loses its capsid and all it is by that point is genetic material. Next, the viral genetic material uses the host cell’s resources to synthesize more genetic material and proteins, replicating itself this way, multiplying and finally they getting itself out of the host cell.

DNA viruses contain DNA as their genetic material while RNA viruses contain RNA as their genetic material. DNA viruses are larger, most contain a double stranded DNA, and they replicate themselves in the nuclei of the host’s cells. RNA viruses are smaller, most contain a single stranded RNA, and they replicate themselves in the cytoplasm of the host’s cells.

Some viruses cause no apparent changes in the host’s cells, being inactive there. Some awaken from their dormant state from time to time and cause distressing changes to the host’s cells, for example, the herpes viruses.

Six species of human coronaviruses have been identified, with one of the species subdivided into two different strains (a strain is a genetic variant, a subtype),  making 7 strains of coronaviruses altogether. 4/7 are mild forms that continually circulate in human population all over the world, producing the symptoms of the common cold. 3/7 produce symptoms that are potentially severe:

1. Middle East Respiratory Syndrome-related Coronavirus (MERS-CoV)- almost 2,500 cases, 34.5% mortality rate.

2. Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV)- more than 8,000 cases, about 10% mortality rate.

3. Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)- almost 4 millions today and almost 300,000 dead (today,  May 8, 2020).

The three listed coronaviruses above, all originated in bats (a zoonotic origin). It is not known if SARS-Cov-2, the virus behind Covid-19, transferred from bats to humans directly, or through an intermediate animal/ host.

All coronaviruses are RNA viruses with a broad range host range, infecting birds, mammals (bats, cows, pigs, ferrets, rabbits, laboratory mice and rats, and humans), but there is no significant evidence of the current Covid-19 coronavirus (SARS-Cov-2) infecting farm animals and pets so far.

SARS-Cov-2 (Cov-2 for short), infect human lungs by its surface binding a “spike” on its surface protein with a human enzyme (ACE2) which is abundant in human lungs cells. The higher the density of ACE2 in a group of cells (tissue), the more Cov-2 bind to the tissues and the more severe the symptoms suffered by the human host.

Most of those who die of Covid-19 have pre-existing conditions, including hypertension (high blood pressure), diabetes, and cardiovascular disease (diseases of the heart and blood vessels), chronic respiratory diseases (such as COPD where patients suffer from chronic poor air flow as a result of a breakdown of lung tissue).

In people younger than 50, the risk of death is less than 0.5%. In people older than 70, the risk is 16 times greater, 8%. According to a data table called “case fatality rates (%) by age and country or US state” in Wikipedia, in children 0-9, the case fatality rate is zero in most countries, 0.1% in Italy, and 0.9% in Sweden. In children and adults 10-19 years old, the case fatality rate is zero in most countries, 0.2% in China and the Netherlands, and 0.4% in Spain. In adults 20-29, the case fatality rate is zero in most countries, 0.1% in Italy and the Netherlands, 0.2% in China, Spain and the US, and 0.4% in Sweden.

More Later.

anita

Dear Reader:

1. Glossary:

pathogen: the word comes from pathos which means suffering, and gen which means the producer of (disease).  A Pathogen may be referred to as an infectious agent, or simply a germ. Pathogens are viruses, bacteria, fungi and parasites that produce disease.

Epidemic: the word comes from epi which means upon and demos which means people. An epidemic is the rapid spread of disease to a large number of people in a given population within a short period of time.

Pandemic: the word comes from pan which means all, and demos which means people. A pandemic is an epidemic that spread across multiple continents, or worldwide.

Endemic infection: the word comes from en which means in or within, and demos which means people. it is an infection that is constantly maintained at a baseline level in a particular area without more added to it from other areas. The seasonal flu is an endemic infection; it occurs simultaneously in large regions of the world (not in one region and then spread out, as in an epidemic turned pandemic).

Crimson Contagion: a simulation administered by the U.S. Department of Health and Human Services from Jan to August 2019 (ending four months before the current pandemic started in China), that tested the capacity of the U.S. federal government and 12 U.S. states to respond to severe influenza pandemic originating in China. The simulation involved a scenario in which tourists returning from China spread a respiratory virus in the US, beginning in Chicago. In less than two months the virus infected 110 million Americans killing more than half a million (currently almost 1.4 million Americans tested positive for Covid-19, and over 81,000 died). Among the key findings: “Federal government lacks sufficient funding to respond to a severe influenza pandemic”, “The United States lacks the production capacity to meet the demands for protective equipment and medical devices such as masks and ventilators imposed by a pandemic”, and “Exercise participants lacked clarity on the roles of different federal agencies”.

Bryan Walsh: a graduate of Princeton University, worked as a foreign correspondent, reporter, and editor for TIME for over 15 years, has reported from more than 20 countries on science and environmental  stories like SARS nd global warming, author of the book End Times: A Brief Guide to the End of the World (2019).

2. www. bbc. com/ future/ article/ .. covid 19 the history of pandemics, article by Bryan Walsh, March 25, 2020. Summary of the article and quotes (my comments are in parentheses):

Over the past 15 years, there’ve been plenty of warnings that “a global pandemic involving a new respiratory disease was only a matter of time”. “In 2019, US President Donald Trump’s Department of Health and Human Services carried out a pandemic exercise named ‘Crimson Contagion'”.

“Throughout history, nothing has killed more human beings than the viruses, bacteria and parasites that cause disease. Not natural disasters like earthquakes or volcanoes. Not war- not even close”

Malaria (an infectious disease caused by a unicellular parasite in mosquitoes that is passed to humans via mosquito bites) still kills nearly half a million people every year. The plague of Justinian (caused by a bacterium) in the 6th Century killed as many as 50 million people, maybe half the global population at the time. The Black Death (caused by the same bacterium) in the 14th century may have killed up to 200 million people. Smallpox (cased by a virus aka viral) killed as many as 300 million people in the 20th century alone. The influenza Pandemic of 1918 (viral) killed 50 to 100 million people, the virus infecting 1 in every 3 people on the planet. HIV (viral), a still ongoing pandemic which still lacks a vaccine, killed about 32 million people, and infected 75 million, with more added every day.

Epidemics are rarely discussed in  history classes, and there are few memorials to the victims of disease. Alfred Crosby authored a book about the 1918 flu: America’s Forgotten Pandemic.

When a virus infects a host, that host becomes a cellular factory to manufacturing more viruses. The symptoms created by infectious viruses and other pathogens (bacteria and unicellular parasites), such as sneezing, coughing or bleeding, cause the spreading of the virus to the next host, and the next. Ro, the Replication Number, is how many people one sick person infects.

It is estimated that the Covid-19 virus’s Ro is at 1.5- 3.5.

The reason that at the beginning of the 19th century the global life expectancy was just 29 years was because so many died from infectious diseases beginning in infancy. Cities in the pre-modern era were able to keep up their populations through a continual infusion of migrants to make up for citizens who died off from disease.

“The development first of sanitation, and then of countermeasures like vaccines and antibiotics, changed all that… It was a victory that won us the modern world as we know it”.

“In the developed world, and increasingly in the developing world, we are now far more likely to die from non-communicative diseases like cancer, heart disease or Alzheimer’s than from a contagion”.

There has been a drastic decline of number of deaths from infectious diseases from about 800 in 1900 to about 60  at the end of the 1990’s, with a brief spike in 1918 (The Influenza Pandemic) and in the 1980s (The AIDS Pandemic).

The reason Covid-19 has been so infectious is that in the past 50 years world population has more than doubled, and cities are densely populated, and we have more livestock than ever in the past, and viruses can leap from animals to humans. Our interconnected global economy, and the ability to get to nearly any spot in the world in 20 hours or fewer, made an outbreak in one place easily arrive to a far away location and spread there. So diseases that would have died out in the past in one location without spreading to new locations, now easily spread to other locations far apart, and in a short time.

Antibiotics saved hundreds of millions of lives since the discovery of penicillin in 1928, but bacterial resistance to antibiotics is growing by the year, a development that doctors believe is “one of the greatest threats to global public health. In fact, 33,000 people die each year from antibiotic resistant infections in Europe alone, according to a 2018 study.

“The spread of vaccine skepticism has been accompanied by the resurrection of long- conquered diseases like measles, leading the WHO in 2019 to name the antivaccination movement one of the world’s top 10 public- health threats.”

When Covid-19 hit the world, human response was on one hand modern: scientists around the world are using cutting- edge tools to rapidly sequence the genome of the coronavirus, and easily communicate and collaborate, information is available to all via the internet, on one hand, and on the other hand, we are doing what our ancestors did to halt an outbreak of a plague: shut down society.

“We need to strengthen the antennae of global health, to ensure that when the next virus emerges- which it will- we’ll catch it faster, perhaps even snuff it out.”

“Just as the eventual emergence of something like Covid-19 was easily predictable, so too are the actions we should have taken to shore ourselves against its coming… We need to double down on the development of vaccines, which will include assuring large pharma companies that their investments won’t be wasted should an  outbreak end before one is ready… our health care systems should have the surge capacity to meet the next pandemic. One ongoing challenge in pandemic preparation is what experts call shock and forgetting. Too often politicians make funding promises in the immediate aftermath of a crisis like SARS and Ebola, only to let those pledges lapse as the memory of the outbreak fades… Somehow, I expect that won’t be the case with Covid-19″.

anita

• This reply was modified 4 years, 7 months ago by .

Dear Reader:

In Sweden, there was 1 death (0.03% of all deaths) of a child, 52 (1.6%) deaths of adults 20-49, 105 (3.1%) deaths of people 50-59, and 3,155 (95.6%) deaths of people 60 and older (most in the 80-90 age group), a total of  3,303 deaths as of May 12.

In Italy, there were the following percentages of deaths by age groups: 0.2% children, 1.3% of 20-49, 2.6% of 50-59, and 92.3% of 60 and older (most in the 80-89 age group) as of May 11.

In New York City, there were no deaths of children, 0.8% deaths of adults 18-44, 7.3% deaths of 45-64, and 84% ages 65 and older (most deaths by far in the 75 and older age group) as of May 12.

(www. statistica. com/ coronavirus death rates by age new York city, and other sources).

It is not known if most children don’t get infected with Covid-19 or if they do get infected but are asymptomatic.  (And it is not known if asymptomatic children are able to pass on the virus to other children and to adults).

A very recent article today, May 13 (www. reuters. com/ health coronavirus usa kids) reads: “U.S. scientists have been working to understand the inflammatory syndrome associated with exposure to the new coronavirus, which has stricken children in Italy, Spain, Britain and the United States. In New York, more than 100 children are reported to have developed the syndrome, which may occur days or weeks after a Covid-19 illness. At least three children have died, the state reported Saturday. All three tested positive for the new coronavirus or had antibodies to it, suggesting the syndrome is linked to Covid-19. The syndrome shares symptoms with toxic shock and Kawasaki disease, with symptoms such as fever, skin rashes, swelling of the glands and, in severe cases, inflammation of arteries of the heart.

Scientists are still trying to determine whether the syndrome is linked with the new coronavirus because not all children with it have tested positive for the virus”.

An article  20 hours ago (www. msn. com/ state directing hospitals to prioritize testing for possible covid-19 related illness in children) reads: “Tuesday, Governor Andrew Cuomo issued an order directing all hospitals to prioritize testing in children displaying symptoms similar to atypical Kawasaki disease and toxic shock-like syndrome…

‘the virus is still surprising us,’ Cuomo said. ‘Initially we thought Covid-19 didn’t affect children, and now we’re dealing with a disturbing issue where we have about 100 cases of an inflammatory disease in children that seems to be created by the virus… The state health department has issued an advisory about the serious inflammation disease called ‘Pediatric Multi-System Inflammatory Syndrome Associated with Covid-19’. Health care providers, including hospitals, must now report all cases of the syndrome in those under the age of 21. New York is also notifying the 49 other states across the country of the emerging cases of this condition”.

* Atypical Kawasaki Disease is rare. Blood vessels become inflamed throughout the body. Despite intense search, no specific pathogen has been identified. Toxic Shock Syndrome is rare as well and is caused by identified pathogens (bacteria), and includes such symptoms as skin inflammation and multiple organ failure. Pediatric multisystem inflammatory syndrome associated with Covid-19 is “a systemic inflammation in children, involving persistent fever and organ dysfunction, associated with exposure to Covid-19… Over 100 cases have been reported in Europe and the US in 2020” (from a new entry in Wikipedia).

A letter by a Dr. Daskalakis, MPH (Master of Public Health) Deputy Commissioner Division of Disease Control New York City Health Department (www1. nyc. gov/ covid-19 pediatric multi system inflammatory syndrome. pdf), reads: “Clinical features vary, depending on the affected organ system.. Patients with this syndrome who have been admitted to pediatric intensive care units have required cardiac and/ or respiratory support..  All patients had subjective or measured fever and more than half reported rash, abdominal pain, vomiting, or diarrhea. Respiratory symptoms were reported in less than half of these patients. Polymerase chain reaction (PCR) testing for SARS-Cov-2 has been positive (4), negative (10).. Six patients with negative testing by PCR were positive by serology… patients should be reported regardless of SARS-Cov-2 PCR test results”.

* Serology testing looks for the presence of antibodies in a person’s blood sample. PCR (Polymerase chain reaction) testing checks for the presence of a pathogen’s genetic material (DNA or RNA) in a person’s blood or mucus sample (PCR Covid-19 testing checks for the presence of SARS-Cov-2’s RNA in a person’s mucus sample taken from deep within the nose).

news. yahoo. com/ gastrointestinal distress without respiratory symptoms may indicate covid, May 13: “Children with gastrointestinal symptoms but without associated respiratory problems could be infected with Covid-19, warns a new Chinese study… children admitted to hospital for non-respiratory symptoms could nonetheless test positive for Covid-19… The study, which points to gastrointestinal symptoms in children as a first manifestation of potential Covid-19 infection in the gastrointestinal tract, notes that receptors in the lungs targeted by the virus are also found in the intestines”.

Wikipedia on Angoiotensin-converting enzyme 2 (ACE2): “ACE2 is an enzyme attached to the outer surface (cell membrane) of cells in the lungs, arteries, heart, kidney, and intestines… ACE2 is present in most organs: ACE2 is attached to the cell membrane of mainly lung type 2 alveolar cells (cells that line the inside of the small and large intestines), enterocytes of the small intestine, arterial and venous endothelial cells (cells that line the inside of blood and lymphatic vessels) and arterial smooth muscle cells in most organs. ACE2 mRNA expression is also found in the cerebral cortex (outer layer in the brain),  striatum (part of the brain), hypothalamus, and brainstem. The expression of ACE2 in cortical neurons (nerve cells in the brain) and glia (cells associated with nerve cells) make them susceptible to a SARS-COv-2 attack, which was the possible basis of anosmia (loss of smell).. and dysgeusia (loss of taste) are seen early in many Covid-19 patients”, “ACE2 also serves as the entry point into cells for some coronaviruses”.

From Wikipedia’s entry on Influenza:  an influenza virus invades a human cell by attaching itself/ binding to  protease, an enzyme in the human cell membrane that breaks down proteins. Next, the proteases breaks down the protein covering of the influenza virus, freeing the viral genetic material to enter the human cell (similar to a Covid-19 virus attaching itself to ACE2, an enzyme in the human cell membrane that breaks down proteins. Next, the ACE breaks down the protein covering of the virus, freeing its genetic material to enter the human cell).

Less virulent influenza viruses can attach themselves  to limited numbers of proteases: those found in the upper respiratory tract: nose, throat and mouth. However, highly virulent strains, such as H5N1 (responsible for the 1918 pandemic,,  also regarded in 2006 “to be the world’s largest pandemic thread, and billions of dollars are being spent researching H5N1 and preparing for a potential pandemic”, Wiki on H5N1), can attach themselves to a wider variety of proteases, such as those found deep in the lungs, causing more severe symptoms allowing the virus to spread throughout the body.

My notes on the content of this post, and more, in the next post, later.

anita

* Regarding the Post Awaiting Moderation” May 15, I already adjusted it and posted it, above, so no need to moderate it, thank you.

anita

Dear Reader:

SARS-Cov-2, the virus behind Covid-19 wreaks havoc in people with weakened immune system because of advancing age and/ or pre-existing health conditions. Globally (worldometer), the death rate in people younger than 50 is 0.5%, in people older than 70, it is 8%, 16 times greater.

In New York City (updated April 21, Wikipedia) 44%of the deaths were of ages 0-44, 22.5% were of deaths were of ages 45-64, and 73% of deaths were of ages 65 and older. Why such a higher rate of death in people 44 and younger in NYC?

www. msn. com/ en-us. news/us/azar lays part of the blame for covid-19 death toll on state of americans health today: “Health and Human Services Secretary Alex Azar on Sunday suggested that the underlying health conditions of Americans, in particular in minority communities, contributed significantly to the death toll from the coronavirus. It is a population with significant unhealthy comorbidities..” he told CNN Jake Tapper on ‘State of the Union.’..

African Americans make up about 13% of the population in those places but 27% of Covid-19 deaths for which race and ethnicity is known”.

www. cdc. gov/ vitalsigns/ aahealth, a publication prior to Covid-19: “new analysis shows that younger African Americans are living or dying of many conditions typically found in white Americans at older ages. The difference shows up in African Americans in their 20s, 30s, and 40s for diseases and causes of death. When diseases start early, they can lead to death earlier. Chronic diseases and some of their risk factors may be silent or not diagnosed during these early years..

African Americans ages 18-49 are 2 times as likely to die from heart disease than whites. African Americans ages 35-64 years are 50% more likely to have high blood pressure than whites.”

Wikipedia on African Americans in New York City: “According to the 2010 Census, New York City had the largest population of black residents of any U.S. city, with over 2 million within the city’s boundaries.. more black people than the entire state of California..”

nymag. com/ intelligencer/2020/03/ coronavirus and its high mortality rate among older patients:

“With around 23% of the population over 65 years old, Italy has one of the world’s oldest populations, and the coronavirus is taking a horrific toll among the elderly… The dramatic rise in mortality rates among older populations can be attributed largely to two factors. First, the immune system becomes weaker as we age, with infections becoming more severe, and taking longer to recover from. Second, older people are more likely to have underlying health concerns: of the 105 Italians who had died from the coronavirus as of March 4, two thirds had at least three preexisting conditions, the most common of which were hypertension, coronary heart disease, and diabetes…

In a World Health Organization report on the outbreak in China, researchers found that the case fatality rate for people with no chronic disease was 1.4%, But for those with cancer, it rose to 7.6%. For those with chronic respiratory disease, it was 8%. For those with cardiovascular disease, it was 13.2%

More, later.

anita

Dear Reader:

Based on Wikipedia on Viral evolution: Most mutations are “silent” and do not result in any obvious changes to the new generation of viruses, but some mutations cause the new viral generation (new viral strain) to be so  different from the earlier strain that the antibodies that developed for the earlier strain do not recognize the new strain. This is how re-infection occurs: a person who recovered from a first infection, having produced effective antibodies for the earlier strain virus, gets re-infected by a new strain of the same virus, and the person’s antibodies don’t recognize the new strain. The new strain,  not having been attacked and stopped by antibodies, proceed to cause illness.

Vaccines and antiviral drugs that were developed for the earlier strain will not be effective for a very different new strain, if the new strain is too  different from the earlier strain.

www. latimes. com/ California/ story/ 2020-05-05/ mutant coronavirus has emerged more contagious than original(May 5): “Scientists have identified a new strain of the coronavirus that has become dominant worldwide and appears to be more contagious than the versions that spread in the early days of the Covid-19 pandemic… The new strain appeared in February in Europe, migrated quickly to the East Coast of the United States and has been the dominant strain across the world since mid-March.. In addition to spreading faster, it may make people vulnerable to a second infection after the first bout with the disease, the report warned. The 33-page report was posted Thursday on BioRxiv, a website that researchers use to share their work before it is peer-reviewed, an effort to speed up collaborations with scientists working on Covid-19 vaccines or treatments.

Scientists with major organizations working on a vaccine or drugs to combat the coronavirus have told The Times that they are pinning their hopes on initial evidence that the virus is stable and not likely to mutate the way influenza virus does, requiring a new vaccine every year. .. The mutation identified in the new report affects the now-infamous spikes on the exterior of the coronavirus, which allow it to enter human respiratory cells. The report’s authors said they felt an ‘urgent need for an early warning’ so that vaccines and drugs under development around the world will be effective against the mutated strain.

In  many places where the new strain appeared, it quickly infected far more people than the earlier strains that came out of Wuhan, China, and within weeks it was the only strain that was prevalent in some nations, according to the report… The report was based on a computational analysis of more than 6,000 coronavirus sequences from around the world collected by the Global Initiative for Sharing All Influenza Data, a public-private organization in Germany. Time and again, the analysis found the new version was transitioning to become dominant.

www. msn. com/ en-us/ news/ world/ china’s new outbreak shows signs the virus could be changing, May 19:

One of China’s top critical care doctors, Dr. Qiu, said yesterday that Covid-19 patients in the northeast of China, in comparison to patients in Wuhan, take longer than 1-2 weeks to develop symptoms after infection (longer incubation period). These north-east patients “carry the virus for a longer period of time and take longer to test negative” than Wuhan patients. “The longer period during which infected patients show no symptoms has created clusters of family infections”, and “it is harder for authorities to catch cases before they spread”. Lockdown measures in two north east provinces in China, a region of 100 million people, have been put in effect as a result of this development. Also, Dr. Qiu said that patients in the northeast cluster “seem to have damage mostly in their lungs, whereas patients in Wuhan suffered multi-organ damage across the heart, kidney and gut”, and among the northeast cluster, only 10% have turned critical. Officials believe that the new cluster stemmed from contact with infected individuals arriving from Russia. Genetic sequencing showed a match between the northeast cases and Russian infections.

But it is not certain that the virus has changed since Wuhan. It may be that the differences observed in the north-east have to do with Chinese doctors observe patients in the north east from an earlier stage of the disease and more thoroughly than did the overwhelmed doctors in Wuhan who attended only to the most serious cases.

“Researchers worldwide are trying to  ascertain if the virus is mutating in a significant way to become more contagious as it races through the human population, but early research suggesting this possibility has been criticized for being overblown.. In theory, some changes in the genetic structure can lead to changes in the virus structure or how the virus behaves.. However, many mutations lead to no discernible changes at all… It’s likely that the observations in China don’t have a simple correlation with a mutation and ‘very clear evidence’ is needed before concluding that the virus is mutating”.

anita

• This reply was modified 4 years, 7 months ago by .