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Blogfinger between the lines: testing, testing, testing.

 

From an infected person: virus is yellow; cell is blue. Electron microscope image.

 

Once a person is infected with coronavirus, the viral invasion can incubate for 1-14 days. A few days before symptoms appear, the infection can be transmitted to another person. All the details of the dynamics of infection are still being worked out.

At some point during the infection, the patient will “sero-convert” meaning his immune system begins to make antibodies which can combat the evil germs.

Antibodies can be found in persons who are recovered from acute coronavirus infection or who are still infected and beginning to make antibodies.

As for the virus itself, it can be detected while it is active by finding it in the respiratory secretions of sick patients or asymptomatic (no symptoms) patients who have yet to show signs such as fever, cough or shortness of breath, usually 2-3 days before symptoms have surfaced.

The virus name is SARS-CoV-2   (ie COVID-19,  or Coronavirus, or 2019 Novel Coronavirus) causing an acute respiratory distress syndrome.  All these names are confusing.  Victims can shed virus for 2-3 days after recovery. Also the virus can be stable for several hours to days in aerosols and on surfaces.  It is active for 24 hours on cardboard and up to to 2-3 days on plastic and stainless steel.

The virus test identifies those persons who have active disease. A sample is taken from a nasal swab.   The Corona test identifies genetic material proving the presence of the virus. This is the test which has received so much publicity in recent weeks.  You can also swab surfaces.

And now we have a 15 minute virus identification test, authorized by the FDA, which will be a huge help in sorting out seemingly normal people and those with mild symptoms suspicious for Corona.  It will make triage at the hospital’s front door be more accurate and will help in many other ways whenever knowing if a person is infected is important.

It would be great if an OTC version were available with guidelines by the CDC. Power to the people!

Abbott Labs will churn out 50,000 tests per day starting next week.

 

Viral antigen stimulates antibody production. RND Systems. com

 

Tests for viral antibodies identify those with immunity.

On April 4, the FDA granted emergency authorization for the first rapid antibody test for COVID-19.  A drop of serum, plasma or whole blood is placed in a well on a small cartridge, and the results are read 15-20 minutes later—

Dr. Krammer at Mt. Sinai Hospital in NYC, where such a test has been developed, says, “That means serological tests could be used to survey a population to determine how widespread infection rates were. It also could allow public health agencies to figure out who is already immune to COVID-19.

“So if you would roll this out on a very wide scale, you could potentially identify everybody who is immune and then ask them to go back to their regular life and go back to work,” Krammer says.

“This approach could be especially useful for health care providers who are working with COVID-19 patients.”

“This is not a test for [ongoing] infections,” he says. “It basically looks for antibodies after the fact, after you had an infection.”

His lab is currently running a serological assay to find potential plasma donors. On Tuesday the FDA approved the emergency use of plasma for critically ill coronavirus patients.

There are many unanswered questions about the pandemic, but you first need the tests and then you can answer the questions.

–Paul Goldfinger, MD.  Blogfinger.net

 

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