by Andrew Walden
The Hawaii Department of Health is throwing cold water on any suggestion that a Corona Virus blood antibody test being widely introduced in Britain, should be imported into Hawaii. In the Governor’s Friday March 27, 2020, COVID-19 bulletin, the DoH explains:
At this time, the DOH is not recommending the adoption of blood testing methods for COVID-19. These blood tests have the possibility to be misleading, and their performance characteristics have not been established.
The DoH has a point, but it has missed another point.
The antibody test being used by the million in Britain produces false negatives. It also produces false positives. The false negatives are dangerous to the uninformed. But the false positives are all potential lifesavers.
As New Scientist, March 27, 2020, explains:
Almost all testing for the virus around the world is based on looking for its genetic sequence. But such tests require nose or throat swabs to be taken by trained personnel and sent to a specialised lab for analysis, and there is a global shortage of equipment. Genetic tests also detect only active infections.
Antibody tests, by contrast, detect the antibodies our bodies produce to kill the virus, which we keep producing even after the virus is eliminated. These tests can reveal who has been infected even after they have recovered. Handheld tests that require only a drop of blood can give results in 10 minutes, and can be mass produced quickly and cheaply.
It takes the body as much as 14 days to begin producing sufficient antibodies to fight COVID-19 off. So anybody taking an antibody test in this critical 14-day period is likely to get a false negative which would lead them to wrongly believe any symptoms they might feel are just a cold or the flu. This false assurance can be deadly to the ignorant.
But the so-called false positives are golden.
Every single positive is either somebody who has antibodies in their bloodstream because they are in the process of fighting off Corona, or because they have vanquished the virus and have a high antibody load swimming around looking for viral particles and not finding them.
The first group of positives need to be quarantined and given medical care.
The second group of positives can be recruited to give blood to save the lives of Corona sufferers who are nearing death in an ICU. An infusion of their antibody laden blood plasma can be used to boost the immune system of another Corona patient whose body has not been as proficient at knocking down the infection.
As Nature explains, March 24, 2020:
Hospitals in New York City are gearing up to use the blood of people who have recovered from COVID-19 as a possible antidote for the disease. Researchers hope that the century-old approach of infusing patients with the antibody-laden blood of those who have survived an infection will help the metropolis — now the US epicentre of the outbreak — to avoid the fate of Italy, where intensive-care units (ICUs) are so crowded that doctors have turned away patients who need ventilators to breathe.
To protect the ignorant from the false assurance they might receive from false negatives, testing should be done in conjunction with every blood draw in Hawaii and treated as a blood screening process rather than a patient testing process.
The few positives this process identifies would then have to be tested again using the existing genetic sequence COVID tests. This second round of testing will separate out the active positives from the recovered Corona patients.
Blood plasma can then be harvested from those who have recovered and used to treat critically ill COVID patients.
UPDATE April 1, 2020: Waikiki doctors to offer blood test that detects exposure to COVID-19
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