Face masks

Evidence That Facemasks Prevent COVID-19

As Delta proliferates while the world tries to get back to normal, requirements to wear facemasks in public are also proliferating. The mask mandates are causing no end of consternation in certain segments of the population, which like to claim that there is no evidence that they prevent disease. Their evidence behind this claim is weak and usually boils down to claiming that the virus is similarly prevalent in states with and without mask requirements. For instance, they like to point out that California, with strict mask mandates, has about the same rate of COVID-19 as Florida, which does not have widespread mask mandates.

But, this is not a strong argument. In research, we carefully design studies to compare experimental vs control groups that are as similar as possible in every way except for the variable we wish to test. In other words, we try to isolate the test variable by making all else as equal as possible. This goal for a well-controlled experiment falls apart when comparing California to Florida—they are very different. Differences include age, population and housing density, reliance on public transportation, climate, humidity, and demographics. All of these variables, if not controlled for, will confound the relationship between mask policies and COVID-19 outcomes because each of these variables also affects the spread of disease.

However, comparing counties within a state helps address at least some of these confounding factors since counties within the same state are generally more similar than two different states at opposite ends of the country. Researchers have done just this in Kansas where 21 counties implemented a mask mandate while the others did not. Counties with a mask mandate saw a significant drop in COVID-19 while counties without a mandate saw a 100% increase in new cases during the period of evaluation.

More recently, the ABC Science Collaboration, a partnership between health scientists, K-12 schools and community leaders, in North Carolina collected infection data from >1 million students and staff members between March-June 2021. More than 7000 students and staff caught COVID-19 during that period and contact tracing showed that >40,000 people had close contact with the infected ones. Very few of these close contacts caught the virus and all of them, the infected cases and their close contacts, wore masks. In other words, in schools with mask mandates, there were no outbreaks despite initial COVID infections. And schools are ripe for creating super-spreader outbreaks.

A systematic review and meta-analysis published in The Lancet, examined the efficacy of face masks in reducing the transmission of different coronaviruses (SARS, MERS, and COVID-19). The authors evaluated 39 studies and found that face masks significantly reduced the risk of coronavirus infection compared to no mask wearing.

An article published in the Proceedings of the National Academy of Sciences in January 2021 also reviewed the evidence supporting the use of face masks and similarly concluded that near-universal adoption of non-medical (i.e., cloth) face masks in public could significantly reduce the R0 value of the virus, which is a measure of how well it spreads. In fact, I earlier discussed in these pages a similar finding by British researchers who concluded that widespread mask-wearing could substitute for herd immunity.

There are several other published studies that reach similar conclusions about facemasks. But, perhaps the most comprehensive study was just reported by researchers at Stanford and Yale. It involved a method called cluster randomization where villages in Bangladesh were randomized to get facemasks or not. It involved some 340,000 people in 600 villages. 100 villages received cloth masks and 200 villages received surgical masks. The remaining 300 villages did not receive any intervention to increase mask wearing. The results showed that increased community masking decreased COVID-19 disease in these real-world settings. Surgical masks performed better than cloth masks at reducing COVID-19 disease, though cloth masks were definitely better than no masks.

On a final note, let me reissue my earlier challenge to anti-maskers: If you really think they do not prevent infection, then next time you have surgery, invite the surgical team to throw the masks out when they open you up.

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400,000 Total COVID-19 Deaths In A Year

Shortly after Thanksgiving, I wrote in these pages how the post-turkey surge moved COVID-19 to the top cause of death in the US. I reported that the disease was killing more than 14,000 people a week, above the ~12,000 killed weekly by the former top killers, heart disease and cancer.

Grim.

It is getting grimmer: Now the CDC estimates that 92,000 people will die from the disease in the next three weeks. That is almost 31,000 deaths a week, more than double the death rate in early December. And, a study just published in the Proceedings of the National Academy of Sciences reported that the average life expectancy in the US in 2020, dropped by more than a year. The study was conducted by researchers from Princeton and the University of Southern California using data from the Institute for Health Metrics and Evaluation.

If the pandemic didn’t take place, the study authors note that a person born in 2020 would, on average, live to about 79 years. The virus shaved almost 1.22 years off of that average life span. Black and Latino populations were projected to suffer significantly greater declines in life expectancy compared to White populations.  Reduced life expectancy among minorities was projected to be about triple that for White populations: life expectancy is projected to be 0.73 years lower for the White population, 2.26 years lower for the Black population, and 3.28 years lower for Latinos.

While 400,000 deaths is very tragic, it is a mere drop in the bucket compared to the many more COVID-19 patients who suffer long term, or even permanent morbidity. More on that later.

Shifting Topics: From June to November, Public Health England, tested thousands of healthcare workers in the UK. They reported that out of 6,614 healthcare workers who tested positive for COVID-19 antibodies, there were 44 reinfections. That is a good rate of protection against reinfection, but the reinfection rate still is surprisingly high.

This means that even though you had the virus or even were vaccinated, you might still be able to pass it on. What should you do?

  • Still get the shot.
  • Still mask up.
  • Still socially distance.
  • Still wash your hands.

In other words, be a good neighbor.

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More Than Half CoV-2 Transmission Comes From People Without COVID-19 Symptoms

The Journal of the American Medical Association just reported that 59% of new CoV-2 infections are likely caused by infected people who do not show COVID-19 symptoms. This conclusion is based on the results of a decision analytical model that assessed the spread from pre-symptomatic, never-symptomatic and symptomatic people infected with CoV-2. 35% of viral transmission came from pre-symptomatic people, and 24% from people who never develop symptoms.  

This means that until the vaccines are widely disseminated, identifying and isolating people with COVID-19 will be much less effective at controlling the spread of the virus than previously thought. Effective control of the disease still requires social isolation measures such as wearing face masks indoors, distancing from others, hand hygiene, and limiting indoor contact with other people.


The Statistics Get Grimmer

As of 8 AM Monday EST, the COVID-19 toll is 14,761,732 total cases and 282,345 total deaths, up nearly 1.4 million cases and nearly 15,500 deaths versus this time a week ago.

That makes COVID-19 the leading cause of death for Americans by a considerable margin, topping heart disease and cancer, which each kill roughly 12,000 people in the U.S. each week.

And still people think the inconvenience of wearing a face mask and socially isolating is a bigger problem!


Timeline Of Early COVID-19 Events

Late 2019: In November 2019, analyses of wire and computer intercepts, coupled with satellite images leads the US National Center for Medical Intelligence to suspect that a contagion was emerging in China’s Hubei Province, specifically in Wuhan, China's 10th largest city with a population of ~11 million (for comparison, NYC has a population of just over 8 million). This intelligence is shared with the US Defense Intelligence Agency, the Pentagon’s Joint Chiefs, and the White House. Around Thanksgiving, analysts report that China’s leadership is aware of a growing epidemic, but decided to keep the details secret from the world.

Dec 31, 2019: Chinese officials inform the WHO about a cluster of 41 patients with a mysterious pneumonia.

In the middle of the night on the 31st, Wuhan officials quietly begin disinfecting its wet market.

Jan 1, 2020: A Chinese CDC team from Beijing arrived in Wuhan and collected 585 “environment” samples from a garbage truck, drains and sewers in the market. They report that 33 of samples test positive for the virus. 14 of the positive samples are from the area of the market where wildlife was traded.

The Wuhan market closes.

The Chinese government prohibits genome sequencing of new coronavirus samples and orders existing viral samples destroyed.

Jan 1-3: Wuhan police silence eight medical doctors they call “rumor mongers,” warning them against talking about the novel disease. One of them, Dr. Li Wenliang, an ophthalmologist, contracts the virus on Jan 8 and dies Feb 7.

Jan 2: The Central Hospital of Wuhan prohibits staff from publicly discussing the disease.

Jan 6: The US CDC issues a Level 1 travel watch with recommendations on washing hands, avoiding animals, animal markets, and contact with unwell people if travelling to Wuhan.

Jan 7: Chinese scientists report that the cause of the Wuhan flu is a novel coronavirus.

Jan 11: China records it first death linked to the new virus.

Jan 12: The Shanghai Public Health Clinical Center, the facility that published the first genome sequence of the virus, closes without reason.

Jan 13: Thailand reports the first coronavirus infection outside China.

Jan 14: The first confirmed case of COVID-19 in the US appears in the Seattle area in a 35 year old man who had recently arrived from Wuhan. However, a recent UCLA examination of its hospital records shows that there was an unexpected 50% spike in patients with respiratory illness beginning Dec. 22 and continuing through the end of February. This raises the possibility that COVID-19 might have been in the US at least a month before this patient was diagnosed with it.

The WHO states that there is no evidence of person-to-person transmission of the virus.

Jan 17: The US CDC sends 100 people to three US airports to screen travelers from Wuhan.

Jan 20: Since health care workers have come down with COVID-19, the WHO announces that there is person-to-person transmission of the virus.

Jan 21: Anthony Fauci, head of the National Institute for Allergy and Infectious Disease says that “this is not a major threat for the people of the United States, and this is not something that the citizens….should be worried about.”

China reports COVID-19 cases across several major cities including Beijing and Shanghai.

Jan 22: Countries begin closing borders and restricting travel. This includes North Korea, Singapore, Vietnam, Russia, Hong Kong, Mongolia, Pakistan, Malaysia, Mexico, Philippines, Sri Lanka, Thailand, UK, Papua New Guinea, Palau, Vanuatu, Kazakhstan, Nepal, Tibet, Canada, Italy, Trinidad, Tobago, Jamaica, Poland, Iraq, and Turkey.

The US State Department issues a Level 4 travel advisory to not travel to China. It also advises that Americans in China should consider departing, and authorizes American diplomatic staff and their families to evacuate China.

Jan 23: China completely isolates Wuhan—no traffic, including planes, and trains, is allowed in or out of the city, and all public transportation within the city is suspended. A few days later the entire Hubei province is shut down. The day before the Wuhan travel ban, 100,000 people leave the city on trains. An estimated 5 million people travel out the area in the days prior to the quarantine.

The WHO declares that the virus is not a Public Health Emergency of International Concern.

Jan 24: Chinese doctors publish in the medical journal, Lancet, the first report on “Clinical Features of Patients Infected With 2019 Novel Coronavirus in Wuhan, China.” It includes the first description of symptom-free infected people. It also reports that 13 of the original 41 cases had no link to the Wuhan wet market, indicating probable human transmission of the virus.

Another report in the same issue of Lancet describes person-to-person of the virus within a family and the WHO documents another case of person-to-person transmission in Vietnam.

The WHO changes its mind and warns the world of a possible pandemic.

Jan 25: The beginning of the Chinese New Year (the year of the Rat). Nancy Pelosi and NYC mayor de Blasio encourage Californians and New Yorkers to participate in Chinese New Year Parades and to visit China Towns in NYC and San Francisco.

Jan 26: Fauci advises, “The American people should not be worried or frightened by this. It’s a very low risk to the United States, but it’s something that we, as public health officials, need to take very seriously.”

China bans all wildlife trade and the Chinese CDC begins developing vaccines against the novel coronavirus.

Chinese police drop their case against eight people accused on January first of spreading false rumors about a new SARS-like virus.

Jan 30: WHO reverses its decision from one week earlier to declare the coronavirus outbreak a Public Health Emergency of International Concern and advises "all countries should be prepared for containment, including active surveillance, early detection, isolation and case management, contact tracing,…”

US health experts agree that a ban on travel from epidemic hot areas is needed.

Jan 31: Trump announces a travel ban from China and declares a Public Health Emergency. US borders close to all foreign nationals who pose a threat of transmitting the virus. U.S. citizens returning from Hubei province in China are quarantined for two weeks.

Feb 1: Joe Biden and Nancy Pelosi accuse Trump of fearmongering and xenophobia for the travel ban.

Feb 3: Fauci predicts that because of travel restrictions, the danger to Americans was “just minuscule.” He also warns against “outlandish extrapolations of fear” and advises that “…there is no reason whatsoever to wear a mask.”

Feb 4: Italians embark on a campaign to hug Chinese to encourage them in the coronavirus fight and as an anti-prejudice statement.

Feb 12: COVID-19 cases begin to spike in S. Korea.

Feb 19: COVID-19 cases begin to spike in Iran.

Feb 21: COVID-19 begins to spike in Italy.

Feb 25: The US CDC warns that clusters of outbreaks are likely to arise in the US and that hospitals, businesses, and schools should begin preparing for social distancing. The US has 57 confirmed COVID-19 cases, 40 of whom are connected to the Diamond Princess cruise ship. While there are no signs of sustained transmission in the US, the warning is based on the rising infections in Iran, Korea and Italy.

New Orleans goes ahead with its Mardi Gras parade and celebration.

Feb 28 and 29: Fauci changes his tune and acknowledges that “It could be really bad,” but also adds, “I don’t think it’s gonna be, because I think we’d be able to do the kind of mitigation (sic). It could be mild.” And, “Right now…there is no need to change anything that you’re doing on a day-by-day basis. Right now the risk is still low, but this could change….I mean this could be a major outbreak.”

March 1: The first confirmed COVID-19 case appears in NYC. More cases rapidly appear in following days and viral sequence analyses traces the source of the virus back to China but via Europe. The travel ban from China seems to have worked, but viral entry from Europe was not expected.

March 8: The entire country of Italy goes into complete lockdown.

March 10: Fauci again advises that “…the risk is relatively low,” but also cknowledges that “there are parts of the country right now that are having community spread in which the risk there is clearly a bit more than that.” He cautions, “…we should like the country to realize that as a nation, we can’t be doing the kinds of things we were doing a few months ago.”

A choir practice in Skagit County Washington is attended by 61 people, including one who had developed a “cold” three days prior. In the days following the 2.5 hour practice, 52 COVID-19 cases occur (an infection rate of 87%). Three are hospitalized and two die from the disease.

March 11: WHO declares a pandemic.

Trump bans all travel from 26 European countries.

March 12: Biden rejects all travel bans saying that viruses do not respect borders.

March 13: Trump declares a national emergency.

March 16: Trump urges Americans to avoid restaurants, bars, unnecessary travel, and groups of more than 10 people.

States begin ordering “shelter in place” restrictions.

March 18: Trump signs the Defense Protection Act that allows the military to provide States with PPE and ventilators from the US strategic reserves. He also announces that the US Navy hospital ships, Comfort and Mercy, will be deployed to the East and West Coasts in case hospitals are overwhelmed by COVID-19 cases.

March 23: NYC confirms 21,000 COVID-19 cases making it the epicenter of the US outbreak.

March 31: More than 1/3 of the world population is under some form of lockdown.

April 3: For the first time, Biden supports travel bans to slow spread of CoV-2.

Summary: No one knew we were facing a once-in-a-generation pandemic. The important question is: “Why did it take so long for the health professionals around the world to recognize the extent of the threat and advise the world to act more forcefully? The answer partly is because this virus did not behave as expected based on recent experience with SARS, MERS, avian flu, swine flu, Zika and Ebola outbreaks. Those viruses did not come with “stealth” vectors, or asymptomatic virus spreaders, which led to much faster and unexpected transmission of Cov-2. Also, the constellation of COVID-19 symptoms were confusing and not as straightforward as, say Ebola, where it is unambiguous how the virus affects people. Finally, this range of often unrelated symptoms associated with COVID-19 is further confounded by the long-lasting adverse health sequelae in many patients that are rare in most other viral infections.

In other words, health professionals had a very steep learning curve with this virus that they did not have with other significant pathogens we have encountered in recent decades.  The professionals had to learn on the fly and are still learning. This timeline reflects that learning curve and shows how professional opinions changed over a matter of weeks, or even days, as new information emerged.

This will happen again.

Note on sources: This timeline was assembled from numerous sources including the Washington Post, The Wall Street Journal, The New York Times, The Guardian, Summit News, CNN online, Real Clear Politics, Yahoo News, Business Insider, Forbes, Wikipedia, ABC News, and several medical journals.


An Invitation To Those Who Refuse To Wear Masks

I have been seeing a LOT of resistance to using face masks during this pandemic, mostly from libertarian or anti-authority types who "don't like to be told what to do." For these people I have a question: do you also believe no one should tell people not to  steal your wallet, or drive drunk? After all, preventing people from hurting others is one of the common features of our laws. Masks protect people from others just like drunk driving laws do.

On other forums, and in this blog here and here, I have presented scientific evidence that masks are effective in retarding the spread of infectious diseases, but these nouveau "experts" keep arguing and ignoring the evidence.

So, I have an invitation for those who think masks are ineffective and say that they will never wear one.

Next time you have surgery, tell your surgeon that you don't believe in face masks and insist that he not wear one during the operation.

Tell him that, even though your insides might be open, you are not worried about the spray from his mouth when he utters spray-worthy things like, "scalPel, Please," "sucTion  Please," and "reTracTion Please."

At this point, I am reminded of the Seinfeld episode when Kramer et al., were in a surgical theater overlooking an operation. Kramer brought in a box of Junior Mints like he was just watching a movie, and while leaning over the rail to watch the operation, he popped the candy in his mouth. Just before the surgeons were getting ready to close, he was putting a mint in his mouth, but it dropped into the body cavity of the patient. That would have been prevented if he had been wearing a mask.

Mints