Here is a detailed summary on where U.S stands on covid -19 tests till date as it is the most affected nation but with the highest number of tests.
As of now, more than 3.4 million coronavirus tests had been conducted in the United States, according to the COVID – 19 Tracking Project, which relies on state public health data. But to curb the pandemic in a country of more than 329 million people, that’s not nearly enough. As a result, researchers are racing to develop new tests that they can scale up quickly.
Here’s where things stand with tests for COVID-19 including those currently used in clinics and others under development.
PCR Based Tests
The current gold standard for diagnostic tests is based on a method that searches for bits of the virus’s genetic material (SN: 3/6/20). Most available tests rely on swabs from a person’s nose or throat, which are then sent to a lab where researchers use a technique called polymerase chain reaction, or PCR, to detect tiny amounts of the coronavirus. PCR-based tests typically take about three to four hours.
On April 10, the U.S. Food and Drug Administration approved an emergency use authorization for a COVID-19 saliva test using a patient’s spit. That test — developed by researchers at Rutgers University in Piscataway, N.J., and now being rolled out in New Jersey — also relies on PCR to detect viral genes. But it skips the step requiring a health care professional to swab the back of a patient’s throat or nose. Instead, patients spit into a tube. The test aims to help with swab shortages and protect health care workers from getting infected from the close contact needed to take a nasal or throat swab.
A Test For Exposure
Researchers and public health officials are also moving beyond diagnostic tests to better understand how far the pandemic may have spread undetected. Blood tests can help uncover people who have been exposed to the virus .
Such tests look for antibodies, an immune protein that the body produces to fight off an infection. These proteins also stick around in the body long after the infection clears. That allows researchers to identify people who didn’t know they had been infected, either because the patient didn’t have symptoms or wasn’t able to get a diagnostic test. Though a few tests have been approved recently by the FDA for emergency use, they are not yet widely available.