Coronavirus: CDC begins retroactive testing to detect undiagnosed Covid-19 cases

Agency to carry out testing on residents who remained un-symptomatic in Covid-19 hotspots

Centers for Disease Control and Prevention (CDC) has began carrying out tests to see how many people in the US have been infected with coronavirus, a spokesperson told Politico.

According to the report, the organisation will even be testing those who never developed symptoms.

STAT reported that testing will focus on three main phases of tests: those who were never diagnosed while in some of the nation’s Covid-19 hotspots, a national survey using samples from different parts of the country, and finally within special populations such health care workers.

The tests, called sero-surveys, will be conducted through blood testing, analysing the antibodies in a person’s blood to detect if they have been exposed to the coronavirus.

Antibody tests are different from those where swab samples are used to determine active cases of Covid-19.

“We’re just starting to do testing and we’ll report out on these very quickly,” Joe Bresee, deputy incident manager for the CDC’s pandemic told reporters.

“We think the serum studies will be very important to understand what the true amount of infection is out in the community.”

Governments have expressed concern that antibody tests are not proving to be as reliable as swab tests.

However, the Food and Drug Administration granted emergency use authorisation of an antibody blood test on Wednesday.

In a letter of authorisation, the organisation said that “it is reasonable to believe” that the test, which is produced by the company Cellex, may be effective in diagnosing Covid-19 cases and that the potential benefits outweigh the risks.

Widespread testing will allow the CDC to determine how far the virus has spread across the US.

If a large number of people are seen to have tested positive for the virus, it could potentially be argued that they could return to work and society.

The CDC has in no way suggested this testing is being undertaken to work towards returning people to the workforce.

Dr Anthony Fauci, one of the top US experts on infectious diseases, said he is ”really confident” that recovered coronavirus patients will have immunity, in an interview with The Daily Show.

“If this virus acts like every other virus that we know, once you get infected, get better, clear the virus, then you’ll have immunity that will protect you against re-infection,” he said, according to Vox.

However, it is still yet to be confirmed whether, or for how long, a person will sustain immunity for the virus after being initially infected with the disease.

The novel coronavirus usually only causes mild to moderate symptoms in most cases, but can lead to more serious complications that can be fatal.

More than 330,000 people have tested positive for the respiratory disease in the US, while the country’s death toll has surpassed 9,500, according to statistics from The John Hopkins University.