May 22, 2020 - Health

CDC is conflating diagnostic and antibody tests for coronavirus

Photo: Pavlo Gonchar/SOPA Images/LightRocket via Getty Images

The Centers for Disease Control and Prevention on Thursday confirmed that it has been combining the results of diagnostic coronavirus tests and coronavirus antibody tests, The Atlantic reports.

Why it matters: Including antibody test results distorts data on the prevalence of the coronavirus and can overstate the ability to safely begin the reopening process.

  • A positive COVID-19 test means a person is currently carrying the coronavirus, while a positive antibody test suggests the individual has been infected in the past.

What they're saying: Harvard professor of global health Ashish Jha told The Atlantic, "Because antibody tests are meant to be used on the general population, not just symptomatic people, they will, in most cases, have a lower percent-positive rate than viral tests."

  • Jha says the CDC's combination of the two tests makes their results "uninterpretable," and that the distortion will "drive down your positive rate in a very dramatic way."

Go deeper

World coronavirus updates

Data: The Center for Systems Science and Engineering at Johns Hopkins; Map: Axios Visuals

New Zealand has only eight active novel coronavirus cases and no COVID-19 patients in hospital after another day of zero new infections. However, the death toll rose to 22.

Zoom in: A top health official told a briefing a 96-year-old woman "was regarded to having recovered from COVID-19 at the time of her death, and COVID-19 is not recorded as the primary cause of her death on her death certificate." But it was decided to include her in the overall tally of deaths related to the virus.

U.S. coronavirus updates

Data: The Center for Systems Science and Engineering at Johns Hopkins; Map: Andrew Witherspoon/Axios. This graphic includes "probable deaths" that New York City began reporting on April 14.

More than 100,000 Americans have died of the coronavirus, according to data from Johns Hopkins — a milestone that puts the death toll far beyond some of the most tragic events in U.S. history.

By the numbers: Over 1.6 million have tested positive in the U.S. Nearly 354,000 Americans have recovered and over 15.1 million tests have been conducted. California became the fourth state with at least 100,000 reported cases of the coronavirus on Wednesday, along with Illinois, New Jersey and New York.

New research suggests coronavirus spread began in U.S. in mid-February

Illustration: Aïda Amer/Axios

New research suggests that the coronavirus outbreak in Washington state was likely started by someone who came to the U.S. in mid-February, not by the first confirmed infection in the country, STAT reports.

Why it matters: The research indicates that the U.S. could have been more successful in mitigating community spread of the virus had it acted sooner.