Crazy change in Virus tests

The CDC, under pressure from Trump, just changed its guidance on who gets testing: People exposed to the virus, but without symptoms, aren't to be tested.

It's crazy. It will spread the disease.

Packing Covid test sample to send to lab.

An Up Close observation of virus testing.

Under the new CDC rules, if you don't have symptoms, don't get tested. CNN described the new guidance this way: 

     "In a shift that perplexed some doctors, the US Centers for Disease Control and Prevention has changed its Covid-19 testing guidelines to say some people without symptoms may not need to be tested, even if they've been in close contact with someone known to have the virus." They went on to quote an emergency room physician, a professor at George Washington University, who said "That's exactly who should be tested.'

Last week I had a fever of 102.6 and widespread muscle soreness, two of the symptoms for Covid. I was tested. Negative. I had something else.

If I had tested positive, they would have sent me home to quarantine. I live with my wife and my Covid-sheltering stepson, the now familiar situation of the adult child moved from a city apartment to live, again, in his childhood basement. The tall office building where he normally works is shut down.

Had I tested positive, I would have immediately moved out of the house to quarantine away from them in an isolated place--if they tested negative. There would be a high probability that if I had it, they would have it. We don't social distance from each other. My wife and I share a bed, and all three of us eat meals together. They would have been exposed, but had no symptom of Covid. 

"If people are getting exposed, and they're
 not getting tested, and they're not isolating,
 that's a huge problem."

They would want to be tested promptly. In some areas people can simply show up at a test center, but not here. We are in a low priority area. A patient needing a physician referral may encounter one--or an insurer--who said they were 'following CDC guidelines" and may not approve the prescription, nor would the insurance company. Both my wife and stepson have lives to live and places to go. If they are Covid-positive, but a-symptomatic, each needs to quarantine, but if not, they could carry on with their lives--away from me. To be good citizens and good stewards of their own health, they would need to be tested.


That was my potential situation. More common ones would be co-workers who test positive. Or someone at a meeting. Or people with whom you shared a meal. Or a barber or housekeeper who tested positive. Or the playmate of ones child.

Question: Why in the world wouldn't the CDC, or Health and Human Services, or the Trump administration want asymptomatic people who had been exposed to be tested??

Answer: Trump has been open about this. We should test less so we have fewer known cases. He wants to manage the number. If a co-worker tests positive, and you don't get tested, well, you must be OK and you aren't added to the list of the infected. It is a "sweep the problem under the rug" approach, a short term cosmetic fix, with the result that the virus spreads faster by exposed asymptomatic people.

Does it matter? One percent of people who get it, die from it, and maybe 3 to 5 percent of people age 70 and older. I am 70. This isn't an abstract, theoretical problem. 

A college classmate, Richard L. Holmes, has been publishing a daily update on the Covid virus status, but wrote his final update yesterday.  He is stopping because the data he was using became useless under the CDC guidelines, so there was no value in continuing to share it. The most useful way to monitor and control the virus was abandoned: test lots of people, including the asymtomatic. 

This blog has attempted to recognize the things Donald Trump has done well. He is an extraordinary self promoter and he had far, far better insight than did Democrats into the racial resentments, and fears of White Americans over demographic change. He changed the Republican Party because he understood its voters better than did its Governors and Senators, and it got him elected president. He became famous and popular.

But his gift for self promotion led him to try to manage his popularity, rather than manage the virus, with catastrophic consequences. 

Richard L. Holmes Testing and Positivity

    "Perhaps the single most important pervasive needed government process is testing for infectious people, without which it is not possible to know where outbreaks are occurring in time to curtail spread. This type of testing is "antigen" testing for whether a person currently has the virus, not "antibody" testing to see if they were exposed at some time in the past. Only "antigen" testing is addressed here.

     People who test positive may in fact be "false positives" -- usually caused by cross-reactivity of a similar shaped antigen to Covid-19. Different tests have different false positive rates, although false positives cause more nuisance and inconvenience than harm. People who test negative may be "false negatives" -- usually caused by a test not sensitive enough to detect low levels of the virus. Different tests have different false negative rates (and the infamous 15 minute test of the last few months was reported to have a 15% false negative rate), and false negatives unleash infectious people on future contacts with neither the person nor the contacts knowing spread is happening, so these are very harmful and even can cause deaths.

     To control the pandemic in a population, governments need to test broad swaths of the public -- not just those who are symptomatic and seek care, nor just those who could cause a lot of spread (like bus drivers). Worst of all would be to test only those people who are symptomatic, since most infectious people do not show symptoms. (The change of the CDC guidance to do exactly this mistake is why I had to stop publishing daily updates, because compliance with CDC guidance means there is no longer a method to tell how many cases are in the states that comply with the CDC bad science.)

     The easiest and quickest way to tell if enough testing is being performed is the positivity rate -- the higher the positivity rate, the more inadequate is the level of testing. My suggested guide:

     Over 10% positivity: Too little testing to be useful -- the outbreak could be just big, or enormous and getting bigger.

     8-10%: Borderline adequacy of testing to estimate whether spread is increasing or not by whether daily new cases are increasing or not.

     5-8%: Adequate testing to assess whether the pandemic is getting better or worse, although not sufficient to control the outbreak.

     3-5%: Adequate testing to assess pandemic status and possibly to control the outbreak if exactly the right people are the ones tested.

     Under 3%: Sufficient testing to suppress the virus, assuming it is paired with contact tracing and isolation of cases.

     Those of you who are Americans looking for positivity rates (and weekly trends) of your state can find the state-specific data, updated daily about 3 AM EDT, at: https://coronavirus.jhu.edu/testing/tracker/overview

     Those of you who want positivity rates for outside of the USA, although these are only at country level and not all countries can be found, will find them at https://coronavirus.jhu.edu/testing/international-comparison"