Percent of Positive COVID-19 Tests on Upward Trend

Ask and ye shall receive. In the comments section of a recent post, Don Rippert makes an interesting observation: “The cue for a serious outbreak seems to be a rise in percent positive for those being tested. That’s why Michigan and Indiana are being watched closely right now. As I recall from the article I read once the positive percentage hits about 15% you can be assured that the sh** is about to hit the fan.”

What, then, is the trend in here in Virginia? The percentage of positive tests is running steadily higher, surpassing 15% at least twice in the past four days of data. If Don’s rule of thumb is correct, we’re near the point where the fecal matter soon will strike the rapidly revolving blade.

Any conclusion comes with caveats, mainly pertaining to the quality and consistency of the data. However, holding all other things were equal, one would expect the percentage of positives should be heading down. With access to very few tests early on, medical practitioners hewed to strict testing protocols. Only patients with symptoms most closely matching those of COVID-19 were tested. One would expect a high rate of hits. As testing kits become more readily available, they began administering somewhat more broadly — targeting front-line healthcare workers, even those who don’t show symptoms.

Duck, you  may not like what’s coming. — JAB

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9 responses to “Percent of Positive COVID-19 Tests on Upward Trend

  1. From recent news reports, it seems that hospitals are still using fairly strict criteria for testing eligibility. If you are not a health care worker or a resident of a congregate facility (e.g. nursing home or prison), you pretty much have to be sick enough to be admitted to the hospital before you will be tested. Even if you exhibit symptoms, but do not have to be hospitalized, you are likely not to be tested. So, I am not surprised that the rate of positives is that high. https://www.richmond.com/news/virginia/our-system-is-broken-richmond-woman-with-covid-19-symptoms-cant-get-tested-so-her/article_259c67e8-b4ec-5f2d-b9b2-a24c57b1a3f3.html#tncms-source=infinity-scroll-summary-siderail-latest

  2. I’ve read so many articles on COVID-19 lately I can’t keep them all straight. I did read one that related various levels of percent positives from testing to an inflection point in deaths per capita. There were a couple of inflection points. If I can find the article I’ll post a link.

    The IHM model predicts that Virginia will peak at 59 deaths on a single day on May 20. Given that we’re recording 5 a day right now we have an ugly road ahead.

    Here are some near term estimates of Virginia COVID-19 deaths from that model:

    Apr 4 – 6
    Apr 5 – 7
    Apr 6 – 7
    Apr 7 – 8
    Apr 8 – 9
    Apr 10 – 11
    Apr 11 – 11
    Apr 12 – 13
    Apr 13 – 14
    Apr 14 – 15
    Apr 15 – 18

    The model continues to pick up steam as would be expected with 40 deaths on May 2.

    The total expected to die in Virginia by Aug 4 is 3,152

    Given that we’re one of the last states to peak I’m hoping that the mitigation efforts will result in a lower number.

    On a per capita basis we have 37 deaths per 100,000. Maryland is projected at 29. North Carolina at 15. DC at 34. WVa at 27.

    I have not been able to figure out why the model has our per capita death rate so much higher than elsewhere. While this is only a model it would be useful to see how the epidemiological model makers associated with the University of Washington see the world.

  3. Iron Law –
    In times of great stress in America, long efforts at secrecy typically blows up in leaders’ faces. Americans don’t like being taken for a ride, being made not only fools, but also the ones who end up holding the bags of sh-t.

  4. I think the testing protocols influence the numbers of positives also but there are other metrics. The number of deaths and the the number of people who had it and survived, the number released from hospitals, the number of false positives, etc.

    To really understand the number – one has to know HOW to understand the numbers… they actually give College degrees for that! And one needs to also understand epidemiology also – and yeah they give degrees for that also.

    What’s interesting is watching Dr. Fauci as well as the fair number of other epidemiologists being interviewed on TV and answering these questions.

    When all of them agree on some point – you know that there’s either a scientific consensus or a massive conspiracy depending on one’s own inclinations.

  5. Have the increases in cases been adjusted for the number of test being administered? In other words, are the number of cases exponentially increasing (in part) because testing is increasing? Likewise, are the eligibility requirements changing? Its hard to look at those number without context. Here’s another interesting site: https://healthweather.us/?mode=Atypical

    • exactly. We’re using proxies here and the question is are they properly normalized?

      Playing with data is not as easy as some folks think. It does take a fair amount of mathematical background to know how to understand the data.

  6. Interesting to go back and read the March 10 post from Rippert which really started the Corona “epidemic” on Bacon’s Rebellion. When the crisis passes we need to revisit those mortality projections.

  7. VDH narrowed the test priorities from March 4 on eliminating general public with symptoms unless hospitalized. The VDH testing guidance always included COVID-19 symptoms even for first responders and healthcare workers. Guidance was the same for clinicians using private labs, but they could use their own judgment. (Not sure if some medical facilities and nursing homes decided to start testing everyone privately or only where there was an outbreak which has been covered in VDH guidance.)

    February 29: DCLS began limited testing udue to small number of available tests, using “clinical and epidemiologic criteria to identify patients most likely to be infected”

    March 4:
    1. Anyone with close contact with lab confirmed case AND symptoms.
    2. Person with international travel to country with Level 2 or 3 advisory AND symptoms or in an area with community transmission AND symptoms.
    3. Nursing home or long term care facility resident WITH symptoms and negative panel for other respiratory viruses and no alternative diagnosis.

    March 13: dropped people with symptoms AND travel or community transmission
    1. person with close contact with lab confirmed case within 14 days AND symptoms.
    2. hospitalized with fever and diagnosed pneumonia and negative for flu and other respiratory pathogens and no alternative diagnosis.
    3. Nursing home or long term care facility resident WITH symptoms and negative panel for other respiratory viruses and no alternative diagnosis.

    MARCH 20. first category no longer anyone with contact & symptoms—restricted to healthcare workers and first reponders; added potential clusters; dropped pneumonia for hospitalized – added priority for people on ventilators

    1. Healthcare workers and first line responders who had contact or cared for a patient with COVID-19 within 14 days of last exposure ANDfever or signs/symptoms of a lower respiratory illness.

    2. Potential clusters of unknown respiratory illness where influenza has been ruled out, with priority for healthcare facility outbreaks. All suspected clusters or outbreaks should be reported to the local health department.

    3. Persons hospitalized AND who tested negative for influenza and other respiratory pathogens on a respiratory virus panel on initial work-up** AND no alternative diagnosis. Priority will be given to ICU admissions or people on ventilators, where circumstances require a confirmed COVID-19 for compassionate use treatment with antivirals.

    4. Person who resides in a nursing home or long-term care facility AND who has fever or signs/symptoms of a lower respiratory illness AND who tested negative for influenza on initial work-up** AND no alternative diagnosis

    March 24:
    dropped contact with lab confirmed case for healthcare workers & first responders
    dropped no alternate diagnosis for hospitalized and congregate living situations
    changed 4th category to include residents and staff of any congregate housing facility.

    1. Healthcare worker or first line responder with fever OR signs/symptoms of a lower respiratory illness.

    2. Potential cluster of unknown respiratory illness where influenza has been ruled out, with priority for healthcare facility outbreaks. All suspected clusters or outbreaks should be reported to the local health department immediately.

    3. Person hospitalized with fever OR signs of lower respiratory illness. Priority will be given to patients where circumstances require a confirmed COVID-19 diagnosis for compassionate use treatment with antivirals.

    4. Person who resides or works in a congregate setting (e.g., homeless shelter, assisted living facility, group home, prison, detention center, jail, or nursing home) AND who has fever or signs/symptoms of a lower respiratory illness AND who tested negative for influenza on initial workup.

    April 2: for potential cluster outbreaks and congregate housing residents and workers – dropped who tested negative for flu etc

    1. Healthcare worker or first responder with fever OR signs/symptoms of a lower respiratory illness.

    2. Potential cluster of unknown respiratory illness, with priority for healthcare facility outbreaks. All suspected clusters or outbreaks should be reported to the local health department immediately.

    3. Person hospitalized with fever OR signs of lower respiratory illness. Priority will be given to patients where circumstances require a confirmed COVID-19 diagnosis for compassionate use treatment with antivirals.

    4. Person who resides or works in a congregate setting (e.g., homeless shelter, assisted living facility, group home, prison, detention center, jail, or nursing home) AND who has fever or signs/symptoms of a lower respiratory illness.

    So do the changes increase or decrease the percentage of positive tests?

  8. So if I read Carol’s comment correctly, the State of Virginia walked off most of the battlefield for lack of tests and its efforts to get tests. Likely this occurred at the very time UVa. ran out of its one million dollar private gift for tests and Uva. was unwilling to spend anymore of its own money, as was the state or anyone else in state.

    Quite a state government, leaving its people to fend for themselves while lying about it all to those very people the state abandoned.

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