CDC is blending counts for COVID cases

The CDC is lumping positive COVID-19 viral and antibody tests together. Here’s why that’s bad. | Live ScienceBy Nicoletta Lanese – Staff Writer – May 2020

The U.S. Centers for Disease Control and Prevention (CDC) and several state health departments have been reporting COVID-19 diagnostic tests and antibody tests as one grand tally, rather than keeping their results separate, The Atlantic reported

Reporting these numbers as a lump sum, rather than two distinct data points, presents several major issues. 

The CDC is doing with COVID cases exactly what they did to opioid overdose death counts: blending two very important separate counts. With overdoses it was counting prescription opioids along with illicit heroin and fentanyl into “opioid overdoses”, which made it look like everyone was overdosing on prescription medication. 

If those two counts are separated, it’s clear that prescription opioids are causing only a tiny (and steadily decreasing) portion of overdoses, while illicit opioid overdoses continue climbing.

as the tests serve profoundly different purposes, “positive” results from either test cannot be interpreted in the same way.

Reporting all the positive results together, as one number, could skew our understanding of how many new COVID-19 cases emerge over time — a crucial metric to help control outbreaks.

I’m shocked, but not terribly surprised that the CDC is doing this. Their utter incompetence in categorizing (or not) illicit opioids versus medical opioids is now displayed again.

But this time the stakes are much higher. I hope this will result in the CDC’s methods and counting to be closely examined to see where else they’ve done this.

Diagnostic tests for COVID-19 work by detecting viral genetic material in nasal swabs, throat swabs and saliva samples collected from patients, Live Science previously reported. The tests, although not 100% accurate, can reveal whether a given patient has an active COVID-19 infection right now, at the time of testing.

Antibody tests cannot be used to diagnose an active COVID-19 infection; rather, the tests scan patient blood samples for evidence of past infections.

A positive antibody test result would indicate that the person has already been exposed to the virus and likely already recovered from an infection.

If a person tests negative on an antibody test, they could still have an active COVID-19 infection, as their body has yet to build up enough specific antibodies to be detected by the tests.

Combining these two signals makes the data difficult to interpret and could be misleading to the public, because the combined number does not reflect the rate of new infection.

I hope the outrage and pushback from other health authorities will finally straighten out the methods that the CDC uses to count and categorize.

With overdose deaths, only a small portion of the population was affected, but with COVID, their mistake involves every American.

In addition, people are most likely to receive a diagnostic test if they’re suspected to be infected, meaning they’re showing symptoms of the disease or have been in contact with an infected person

The percentage of positive diagnostic tests provides a sense of how much virus is currently circulating in a community, and if skewed, that warped statistic could wrongly influence public health policy decisions.

Just like the warped counts of “opioid overdoses” led to a crackdown on prescription opioids instead of illicit opioids.

When asked about the mess-up, CDC spokesperson Kristen Nordlund said that the agency “hopes” to separate the data on their COVID Data Tracker within the next few weeks.

Now, if they would only do the same for overdose deaths.

Other thoughts?

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