Cartoon – Covid Dining

Political Cartoon on Twitter: "Dave Brown's @Independent cartoon...  #RishiSunak #SummerStatement #EatOutToHelpOut #COVID19 #Coronavirus # SuperSpreader - political cartoon gallery in London  https://t.co/dePcTdnXF6… https://t.co/XDxWE1jDGh"

Cartoon – Sheep will be Sheep

Covid Lemmings

Cartoon – Talk About Super Spreaders

6-02 cartoon | Cartoons | heraldandnews.com

Cartoon – Coronavirus Mask Fashions

5-27 cartoon | Cartoons | heraldandnews.com

A single conference may have seeded 20,000 COVID cases

https://mailchi.mp/95e826d2e3bc/the-weekly-gist-august-28-2020?e=d1e747d2d8

COVID-19 'superspreaders' behind most new cases, researchers say | wcnc.com

A conference bringing together 175 Biogen leaders in Boston during the last week of February demonstrated the anatomy of a superspreader event: attendees from all over the world working, eating and drinking together, at a time when little was known about COVID-19 and few precautions were taken.

A new study reveals the magnitude of spread of this single event: 20,000 COVID infections may have been linked to the conference by early May, orders of magnitude greater than the previously reported 99 cases. A group of researchers evaluated the viral genomes from 772 patients across the greater Boston area, finding over 80 separate introductions of the virus, primarily from Western Europe or elsewhere in the US.

But the Biogen event was far and away the largest source of infections, accounting for 37 percent of investigated cases, which extrapolates to an estimated 20,000 cases across the area (the event also seeded clusters in several states and overseas).

Many patients with the Biogen virus had no direct connection with the event, including a large number of homeless individuals.

As college campuses reopen and states flirt with allowing larger gatherings, the study provides an important lesson of the potential for exponential spread of the virus when left unchecked by preventive measures, and the need for testing and contact tracing to quickly stop the chain of transmission. 

 

COVID-related controversy and hope amid a week of politics

https://mailchi.mp/95e826d2e3bc/the-weekly-gist-august-28-2020?e=d1e747d2d8

Democracy vs. disease: the role of freedom in facing pandemics | University  of Nevada, Reno

Week two of the 2020 Pre-Recorded Virtual Presidential Convention-thon wrapped up Thursday night, albeit with a decidedly less Zoom-Webex-FaceTimey feel for this week’s Republicans compared to last week’s Democrats. As delegates and VIPs sat cheek-by-jowl at several in-person events, with scarce masking and plenty of loud cheering, the viewer was left hoping that a rigorous attendee COVID testing protocol was being used.

That hope may have been dashed by a significant change to testing guidelines from the Centers for Disease Control and Prevention (CDC), which reversed course on Monday by recommending asymptomatic people who have been exposed to the coronavirus should no longer be tested.

The altered guidance drew sharp rebukes from doctors and infectious disease experts, who worried that it would undermine the ability to track the spread of the virus, which has now claimed more than 181,000 American lives. The flap over testing guidelines came at the same time as Food and Drug Administration (FDA) commissioner Stephen Hahn was forced to apologize for misleading claims he made over the weekend about the efficacy of convalescent plasma in treating COVID patients. In announcing an Emergency Use Authorization (EUA) for the treatment, Hahn dramatically overstated evidence supporting the lifesaving ability of the therapy. The missteps by CDC and FDA officials were undoubtedly an unwelcome distraction for the Trump administration, overshadowing the president’s bold promise in his acceptance speech that a COVID vaccine would be available before the end of the year.

There was hopeful news on the COVID front this week as well. In what was quickly hailed as a “game changer” in solving the nation’s faltering ability to deliver timely test results, Abbott Laboratories was granted its own EUA for a 15-minute, $5 rapid antigen test, which does not require laboratory analysis. The company plans to produce tens of millions of the new BinaxNOW test kits in the next month, and the US government has agreed to acquire nearly all of the 150M tests the company will produce by the end of the year, at a $760M purchase price. Although some antigen tests have been cited for accuracy problems, the FDA said that the new Abbott test delivers correct positive tests 97.1 percent of the time, and correct negative tests 98.5 percent of the time.

Rapid, reliable point-of-care testing could allow for safer return to schools, workplaces, and public gatherings, and if successfully deployed will be an essential tool in managing the impact of the virus until effective vaccines are fully developed, launched, and administered. A genuine ray of hope as the nation looks ahead to the fall and winter.

US coronavirus update: 5.9M cases; 181K deaths; 81.8M tests conducted.

 

 

Patchwork approach to contact tracing hampers national recovery

Patchwork approach to contact tracing hampers national recovery

Patchwork approach to contact tracing hampers national recovery | TheHill

A patchwork approach to contact tracing across state health departments is making it increasingly difficult to know where people are getting exposed to COVID-19.

While some states like Louisiana and Washington state publicly track detailed data related to COVID-19 cases in bars, camps, daycares, churches, worksites and restaurants, most states do not, creating obstacles to preventing future cases.

The extensive spread of the virus, combined with the country’s 50-state approach to pandemic response, has led to a dearth of information about where transmissions are occurring. Those shortcomings are in turn complicating efforts to safely open the economy and to understand the risks associated with certain activities and settings.

Experts know COVID-19 spreads in crowded indoor spaces, but more specifics could help state and local lawmakers strike a better balance between public health needs and those of the economy.

“If you want to take a more targeted approach to public health measures, the more information you have the better,” said Joshua Michaud, an associate director for global health policy at the Kaiser Family Foundation and an infectious disease epidemiologist.

“Rather than have a blunt, close-everything-down approach, you could be a bit more targeted and surgical about how you implement certain measures,” he added.

The Hill asked every state for information about the data they collect and share as part of their contact tracing programs, one of the main tools public health officials have to slow the spread of COVID-19.

Most states release information about outbreaks and cases at congregate settings like nursing homes, meatpacking plants, and prisons, which comprise the majority of cases. But there is less information publicly available about the numbers of cases or outbreaks tied to other settings commonly visited by people.

A handful of states including ArkansasColoradoKansasLouisianaMaryland, Michigan, Ohio, Rhode Island and Washington track and publicly release data on the settings where COVID-19 outbreaks are occurring, according to responses from state health departments.

For example, Louisiana has tied 468 cases to bars in the state, but most of the new cases in the past week have been tied to food processing plants.

In The Hill’s review of publicly available state data, other settings for COVID-19 transmission include restaurants, childcare centers, gyms, colleges and schools, churches, retailers, weddings and other private social events. It is not clear how widely those settings contributed to infections because widespread transmission of the virus means many people who get sick do not get interviewed by contact tracers — over the past week, there has been an average of 42,000 confirmed cases, though many more are likely going undetected.

State health departments in Idaho, Illinois, Massachusetts, Mississippi, Missouri, New Hampshire, North Carolina, South Carolina, Tennessee, Texas, Vermont, Virginia and West Virginia told The Hill they don’t track location data.

Utah tracks outbreaks and cases tied to workplaces and schools, but not restaurants or bars.

Arizona, California, Delaware, Indiana, Oregon and Pennsylvania track infection locations, but don’t release it to the public.

“The number of people getting COVID-19 from isolated, identifiable outbreaks, such as those in long term care facilities, is decreasing, and more people are contracting COVID-19 from being out and about in their community, such as when visiting restaurants and bars,” said Maggi Mumma, a spokeswoman for the Pennsylvania Department of Health.

Bars, indoor dining and gyms are still closed in most of New York and New Jersey, so there is no current data to track for those settings.

But the state health departments also don’t release data on outbreaks or cases tied to other settings like childcare or retail stores.

MinnesotaMontanaNorth Dakota and Wisconsin release the number of cases tied to outbreaks in the community but do not go into specifics about possible transmission sites.

For example, Minnesota lists nearly 7,000 cases as being tied to “community” exposure, but that includes settings like restaurants, bars and workspaces.

In Iowa, a state health department spokesperson said the agency is working on extracting and sharing this type of data on its website, while Maine would not say if they track by specific location.

The remaining state health departments did not respond to multiple requests for comment from The Hill and don’t have information about outbreaks or exposure settings on their websites.

Several states said local health departments may be tracking infection locations even if the state is not.

Experts said such a decentralized approach can miss outbreaks if local departments aren’t communicating with each other, meaning any data should be public.

“I do think it would be very valuable for states to make that information public,” said Crystal Watson, assistant professor at Johns Hopkins Bloomberg School of Public Health.

“It helps us collectively get a better understanding as policymakers, as people trying to help in the response. It can also help with personal decision making for people to understand … where it’s most dangerous to go related to getting infected,” Watson said.

The disparities between state health departments are partially due to a lack of federal guidance.

There are no federal requirements on the information contact tracers collect; guidelines vary from state to state, and sometimes from county to county.

Tracking data about where people are getting sick would allow states to take a “cluster busting” approach, experts said, by working backwards from confirmed cases to find where patients might have first contracted the disease, potentially stopping future outbreaks.

That approach requires a change in mindset for contact tracers, who typically focus on reaching close contacts of confirmed cases who might have been exposed to the virus. But research shows between 10 and 20 percent of people are responsible for about 80 percent of new infections, mostly through so-called super-spreader events.

“We know that the way this virus has transmitted is highly clustered groups and anytime you have settings where a lot of people are together in one place,” said Kaiser’s Michaud.

“Collecting good information on this — the cluster busting approach — is a good way to find out where your prevention efforts can have the best bang for your buck,” he said.

At the same time, some state programs are still not operating at full force and are struggling to keep up with widespread infections.

“I think that many parts of the country, especially outside of the Northeast … simply have too many cases to use contact tracing as the primary public health measure to control cases,”  said Stephen Kissler, a research fellow at the Harvard T.H. School of Public Health.

“It’s just not enough,” he said. “We just don’t have enough resources, and in a lot of these places enough contact tracers, to follow up on all of the cases.”

 

 

 

 

 

Warren Buffett: An appreciation

https://www.mckinsey.com/business-functions/strategy-and-corporate-finance/our-insights/warren-buffett-an-appreciation?cid=other-eml-alt-mip-mck&hlkid=500c2a923cdd4ff19d66acac00e2a9fa&hctky=9502524&hdpid=e758f2ed-7de7-4263-9faa-7daf7b3bdaa7

Celebrating Warren Buffett on his 90th birthday | McKinsey

As Warren Buffett turns 90, the story of one of America’s most influential and wealthy business leaders is a study in the logic and discipline of understanding future value.

Patience, caution, and consistency. In volatile times such as these, it may be difficult for executives to keep those attributes in mind when making decisions. But there are immense advantages to doing so. For proof, just look at the steady genius of now-nonagenarian Warren Buffett. The legendary investor and Berkshire Hathaway founder and CEO has earned millions of dollars for investors over several decades (exhibit). But very few of Buffett’s investment decisions have been reactionary; instead, his choices and communications have been—and remain—grounded in logic and value.

Buffett learned his craft from “the father of value investing,” Columbia University professor and British economist Benjamin Graham. Perhaps as a result, Buffett typically doesn’t invest in opportunities in which he can’t reasonably estimate future value—there are no social-media companies, for instance, or cryptocurrency ventures in his portfolio. Instead, he banks on businesses that have steady cash flows and will generate high returns and low risk. And he lets those businesses stick to their knitting. Ever since Buffett bought See’s Candy Shops in 1972, for instance, the company has generated an ROI of more than 160 percent per year —and not because of significant changes to operations, target customer base, or product mix. The company didn’t stop doing what it did well just so it could grow faster. Instead, it sends excess cash flows back to the parent company for reinvestment—which points to a lesson for many listed companies: it’s OK to grow in line with your product markets if you aren’t confident that you can redeploy the cash flows you’re generating any better than your investor can.

As Peter Kunhardt, director of the HBO documentary Becoming Warren Buffett, said in a 2017 interview, Buffett understands that “you don’t have to trade things all the time; you can sit on things, too. You don’t have to make many decisions in life to make a lot of money.” And Buffett’s theory (roughly paraphrased) that the quality of a company’s senior leadership can signal whether the business would be a good investment or not has been proved time and time again. “See how [managers] treat themselves versus how they treat the shareholders .…The poor managers also turn out to be the ones that really don’t think that much about the shareholders. The two often go hand in hand,” Buffett explains.

Every few years or so, critics will poke holes in Buffett’s approach to investing. It’s outdated, they say, not proactive enough in a world in which digital business and economic uncertainty reign. For instance, during the 2008 credit crisis, pundits suggested that his portfolio moves were mistimed, he held on to some assets for far too long, and he released others too early, not getting enough in return. And it’s true that Buffett has made some mistakes; his decision making is not infallible. His approach to technology investments works for him, but that doesn’t mean other investors shouldn’t seize opportunities to back digital tools, platforms, and start-ups—particularly now that the COVID-19 pandemic has accelerated global companies’ digital transformations.

Still, many of Buffett’s theories continue to win the day. A good number of the so-called inadvisable deals he pursued in the wake of the 2008 downturn ended paying off in the longer term. And press reports suggest that Berkshire Hathaway’s profits are rebounding in the midst of the current economic downturn prompted by the global pandemic.

At age 90, Buffett is still waging campaigns—for instance, speaking out against eliminating the estate tax and against the release of quarterly earnings guidance. Of the latter, he has said that it promotes an unhealthy focus on short-term profits at the expense of long-term performance.

“Clear communication of a company’s strategic goals—along with metrics that can be evaluated over time—will always be critical to shareholders. But this information … should be provided on a timeline deemed appropriate for the needs of each specific company and its investors, whether annual or otherwise,” he and Jamie Dimon wrote in the Wall Street Journal.

Yes, volatile times call for quick responses and fast action. But as Warren Buffett has shown, there are also significant advantages to keeping the long term in mind, as well. Specifically, there is value in consistency, caution, and patience and in simply trusting the math—in good times and bad.

 

 

Battle over COVID-19 school openings goes to the courts

Battle over COVID-19 school openings goes to the courts

Nearly 800 COVID-19 lawsuits have been filed, according to law firm's  tracker

Teachers unions are waging court fights across the country aimed at unwinding what they say are unsafe and politically motivated timetables for reopening schools that risk exposing personnel to the coronavirus pandemic.

State officials eager to ramp up brick-and-mortar operations are facing lawsuits from Florida to Texas to Iowa over reopening plans as well as access to the COVID-19 infection data needed to monitor the rate of spread within school communities. 

At the same time, lawsuits are flying from the opposition direction: Parents in several states, including New York, Massachusetts and Oregon, dissatisfied with web-based teaching alternatives, are suing to force state officials to reopen physical schools sooner as courts are increasingly called upon to referee the fight over education in the age of coronavirus.

“A legal storm is brewing as safety and social distancing requirements for a physical return to school begin to take shape around the country,” Maria Ferguson, executive director of the Center on Education Policy at George Washington University, wrote on the education website The 74.

As millions of students prepare for the first day of school — whether in-person, remote or a hybrid of the two — the fight over the reopening physical school buildings is likely to intensify.

The debate over in-person K-12 instruction planning is inseparably tied to the issues of child care needs and parents’ ability to return to the workforce to help revive the struggling economy, all of which is playing out against the backdrop of a fast-approaching November election in a country that has seen nearly 6 million cases and more than 181,000 deaths from COVID-19.

Perhaps the highest-profile legal battle is taking place in the courts of Florida, where Republican Gov. Ron DeSantis signed off last month on an emergency order over school reopenings.

Under the order, most Florida school districts would be required to hold in-person classes five days a week by the end of August or risk losing funding. President Trump, who counts DeSantis as a close ally, has also threatened to cut off federal funding for schools if they do not resume in-person learning this fall.

The Florida policy prompted a lawsuit from the Florida Education Association (FEA), a statewide teachers union, and several other plaintiffs in favor of a more cautious return to in-person teaching.

“Public schools are not designed for COVID safety, and indeed, the government has recognized that they are high-contact environments,” said Kendall Coffey, the lead plaintiff’s attorney in the Florida case, who likened prematurely opened schools to “disease factories” and called the Florida policy “financial bullying.”

There are any number of issues, in terms of hallway sizes, the flow of students in and out of classrooms, ventilation, even how many students go into the bathroom,” he told The Hill. “There are many elements that are virtually impossible to guarantee when you’re dealing with children in large amounts.”

On Aug. 24, a Florida judge ruled in favor of the union and temporarily halted the statewide order. In his decision, Judge Charles Dodson struck down the order’s unconstitutional provisions and blasted DeSantis for having “essentially ignored” the state’s constitutional requirement that schools be operated safely.

“The districts have no meaningful alternative,” wrote Dodson, of Leon County. “If an individual school district chooses safety, that is, delaying the start of schools until it individually determines it is safe to do so for its county, it risks losing state funding, even though every student is being taught.”

A Florida appeals court agreed to temporarily halt Judge Dodson’s order from taking effect while DeSantis appeals.

The state contends that the benefit of in-person instruction outweighs the health risks associated with reopening brick-and-mortar schools. Some Florida school officials have also declined to disclose incidents of positive COVID-19 cases to school communities, citing the need for patient privacy. 

Attorneys for Florida have also argued in hearings that courts should not substitute their judgment for that of policymakers who have balanced all the equities and decided a prompt in-person reopening is the best policy.

Randi Weingarten, president of the American Federation of Teachers (AFT), one of the largest teachers unions in the country, said Florida has its priorities backward.

“What their arguments show is that they don’t care about human life,” Weingarten told The Hill.

According to Weingarten, internal AFT polling in June showed that about 3 in 4 teachers said they would be comfortable returning to the classroom if guidelines from the Centers for Disease Control and Prevention (CDC) were implemented in schools.

But she predicts that attitudes among teachers have shifted dramatically in past months as the Trump administration has failed to adequately manage the virus to ensure schools can be reopened safely.

“We’re polling right now,” she said. “And my hunch is that just like the public polls, it’s totally flipped.”

The AFT is backing lawsuits in Florida, New Mexico and Texas. Before schools can reopen safely — for what Weingarten calls “the biggest move indoors that the nation has done since March” — the group says local positivity rates should be below 3 percent and schools should have visibility into daily transmission rates. 

The union is also pushing for protocols that involve testing, contact tracing and isolation and implement best practices from the CDC for things such as ventilation, cleaning, physical distancing, mask-wearing and other safeguards.

As teachers unions make their case in court, parents in at least five states have filed lawsuits of their own to accelerate school reopenings.

A nonprofit litigation group called the Center for American Liberty, co-founded by lawyer and GOP official Harmeet Dhillon, is backing one such suit in California. Democratic Gov. Gavin Newsom’s restrictions on in-person school openings in the Golden State will affect an estimated 80 percent of K-12 students.

“The effects of this ham-handed policy are as predictable as they are tragic,” the lawsuit filed in a federal court in California states. “Hundreds of thousands of students will essentially drop out of school, whether because they lack the technological resources to engage with ‘online learning’ or because their parents cannot assist them.”

The litigation raises concerns about everything from school closures exacerbating the achievement gap and disproportionately harming special needs students and those without convenient internet access to challenges over the constitutional validity of government health orders.

Weingarten, of AFT, said it’s important to remember that despite seemingly irreconcilable differences over the policy details, all parties want to see schools reopen as soon as it’s safe to do so.

“None of us believes that remote is a substitute,” she said. “It’s a supplement.”

 

 

Top U.S. Officials Told C.D.C. to Soften Coronavirus Testing Guidelines

The Centers for Disease Control and Prevention abruptly changed its recommendations, saying people without Covid-19 symptoms should not get tested.

 Trump administration officials on Wednesday defended a new recommendation that people without Covid-19 symptoms abstain from testing, even as scientists warned that the policy could hobble an already weak federal response as schools reopen and a potential autumn wave looms.

The day after the Centers for Disease Control and Prevention issued the revised guidance, there were conflicting reports on who was responsible. Two federal health officials said the shift came as a directive to the Atlanta-based C.D.C. from higher-ups in Washington at the White House and the Department of Health and Human Services.

Adm. Brett P. Giroir, the administration’s coronavirus testing czar, called it a “C.D.C. action,” written with input from the agency’s director, Dr. Robert R. Redfield. But he acknowledged that the revision came after a vigorous debate among members of the White House coronavirus task force — including its newest member, Dr. Scott W. Atlas, a frequent Fox News guest and a special adviser to President Trump.

“We all signed off on it, the docs, before it ever got to a place where the political leadership would have, you know, even seen it, and this document was approved by the task force by consensus,” Dr. Giroir said. “There was no weight on the scales by the president or the vice president or Secretary Azar,” he added, referring to Alex M. Azar II, the secretary of health and human services.

Regardless of who is responsible, the shift is highly significant, running counter to scientific evidence that people without symptoms could be the most prolific spreaders of the coronavirus. And it comes at a very precarious moment. Hundreds of thousands of college and K-12 students are heading back to campus, and broad testing regimens are central to many of their schools’ plans. Businesses are reopening, and scientists inside and outside the administration are growing concerned about political interference in scientific decisions.

Democratic governors who were weighing how to keep the virus contained as their economies and schools come to life said limiting testing for asymptomatic citizens would make the task impossible.

“The only plausible rationale,” Gov. Andrew M. Cuomo of New York told reporters in a conference call from Albany, N.Y., “is that they want fewer people taking tests, because as the president has said, if we don’t take tests, you won’t know the number of people who are Covid-positive.”

Over the weekend, the Food and Drug Administration, under pressure from Mr. Trump, gave emergency approval to expand the use of antibody-rich blood plasma to treat Covid-19 patients. The move came just days after scientists, including Dr. Anthony S. Fauci, the nation’s top infectious disease expert, and Dr. Francis S. Collins, the director of the National Institutes of Health, intervened to stop the practice because of lack of evidence that it worked.

The move echoed a decision by the Food and Drug Administration to grant an emergency use waiver for hydroxychloroquine, a malaria drug repeatedly sold by Mr. Trump as a treatment for Covid-19. The agency revoked the waiver in June, when clinical trials suggested the drug’s risks outweighed any possible benefits.

The testing shift, experts say, was a far more puzzling reversal. Dr. Giroir said the move was “discussed extensively by” members of the White House coronavirus task force, and he named Dr. Redfield, Dr. Atlas, Dr. Fauci and Dr. Stephen M. Hahn, the commissioner of food and drugs. Notably, he did not name Dr. Deborah L. Birx, the White House coronavirus response coordinator. But he said Dr. Fauci was among those who had “signed off.”

In a brief interview, Dr. Fauci said he had seen an early iteration of the guidelines and did not object. But the final debate over the revisions took place at a task force meeting on Thursday, when Dr. Fauci was having surgery under general anesthesia to remove a polyp on his vocal cord. In retrospect, he said, he now had “some concerns” about advising people against getting tested, because the virus could be spread through asymptomatic contact.

“My concern is that it will be misinterpreted,” Dr. Fauci said.

The newest version of the C.D.C. guidelines, posted on Monday, amended the agency’s guidance to say that people who had been in close contact with an infected individual — typically defined as being within six feet of a person with the coronavirus and for at least 15 minutes — “do not necessarily need a test” if they do not have symptoms.

Exceptions might be made for “vulnerable” individuals, the agency noted, or if health care providers or state or local public health officials recommended testing.

Dr. Giroir said the new recommendation matched existing guidance for hospital workers and others in frontline jobs who have “close exposures” to people infected with the coronavirus. Such workers are advised to take proper precautions, like wearing masks, socially distancing, washing their hands frequently and monitoring themselves for symptoms.

He argued that testing those exposed to the virus was of little utility, because tests capture only a single point in time, and that the results could give people a false sense of security.

“A negative test on Day 2 doesn’t mean you’re negative. So what is the value of that?” Dr. Giroir asked, adding, “It doesn’t mean on Day 4 you can go out and visit Grandma or on Day 6 go out without a mask on in school.”

The guidelines come amid growing concern that the C.D.C., the agency charged with tracking and fighting outbreaks of infectious disease, is being sidelined by its parent agency, the Department of Health and Human Services, and the White House. Under ordinary circumstances, administering public health advice to the nation would fall squarely within the C.D.C.’s portfolio.

Experts have called the revisions alarming and dangerous, noting that the United States needs more testing, not less. And they have expressed deep concern that the C.D.C. is posting guidelines that its own officials did not author. A former C.D.C. director, Dr. Thomas R. Frieden, railed against the move on Twitter on Wednesday:

Dr. Tom Frieden
@DrTomFrieden
Two unexplained, inexplicable, probably indefensible changes, likely imposed on CDC’s website. * Dammit, if you come from a place with lots of Covid, quarantine for 14 days * If you’re a contact, get tested. If +, we can trace your contacts and stop chains of spread. A sad day.

Later, in an interview, Dr. Frieden elaborated. He noted that the C.D.C. had recently dropped its recommendation that people quarantine for 14 days after traveling from an area with a high number of cases to one where the virus was less prevalent. And he reiterated that testing the contacts of those infected was an important means of curbing the spread of the virus.

“We don’t know the best protocol for testing of contacts: Should you test all contacts? That’s the kind of study that frankly needs to get done,” Dr. Frieden said. But absent the answer to that question, he added, “I certainly wouldn’t say, ‘Don’t test contacts.’”

Democrats, including Speaker Nancy Pelosi and two governors — Mr. Cuomo and Gavin Newsom of California — were outraged by the changes. Mr. Newsom said California would not follow the new guidelines, and Mr. Cuomo blamed Mr. Trump.

Representative Frank Pallone Jr. of New Jersey, a Democrat and the chairman of the House Energy and Commerce Committee, also chimed in on Twitter: “The Trump Admin has a lot of explaining to do. #COVID19 testing is essential to stopping the spread of the pandemic. I’m concerned that CDC is once again caving to political pressure. This simply cannot stand.”

Mr. Trump has suggested that the nation should do less testing, arguing that administering more tests was driving up case numbers and making the United States look bad. But experts say the true measure of the pandemic is not case numbers but test positivity rates — the percentage of tests coming back positive.

As Dr. Giroir denied that politics was involved, he encouraged the continued testing of asymptomatic people for surveillance purposes — to determine the prevalence of the virus in a given community — and said such “baseline surveillance testing” would still be appropriate in schools and on college campuses.

“We’re trying to do appropriate testing, not less testing,” he said.

Still, the revisions left many public health officials scratching their heads. They might have made sense when the United States was experiencing a shortage of tests, some experts said, but that no longer appears to be the case. Dr. Frieden, however, said it was possible the administration was trying to conserve testing in case of another surge.

“The problem is we have too many cases, so there is basically no way to keep up the testing if you have a huge outbreak,” he said.

Jennifer Nuzzo, an epidemiologist at Johns Hopkins Bloomberg School of Public Health, said she was “not as up in arms about the content of the guidelines” as she was about the idea that the C.D.C.’s own experts did not write them — and that C.D.C. officials were referring all questions about them to the health department in Washington.

“These guidelines are clearly controversial, and many are calling on C.D.C. to explain its rationale for them, but C.D.C. is unable to comment,” she said in an email. “This is really dangerous precedent, and I fear it will erode public trust in C.D.C.”