According to the World Health Organization, over 2 million new cases of COVID-19 were reported last week. So far, about 37 million people have had the virus. However, the world faced a shortage of tests even in the first wave of SARS-CoV-2. Now, as wave 2 of the virus hits, the world continues to scramble to get enough tests.
In Europe and North America, countries are using antigen tests to quickly identify those who are infected. Antigen tests give results in minutes but are less accurate than the gold-standard, PCR (polymerase chain reaction) tests used for true diagnosis. PCR tests look for genetic components of the virus in the patient sample. Countries worldwide have suffered from shortages of PCR tests for SARS-CoV-2.
Americans hoping for PCR test results this summer often had to wait for a week or more, due to bottlenecks in test supply and problems with laboratory capacity. Antigen tests not only give results in minutes, they are easier to use and much cheaper than PCR tests, which must be done in a laboratory. However, antigen tests can produce more false negatives.
Both antigen and PCR tests require a nasal or throat swab.
Think of it as something like taking the rapid strep test in the doctor’s office, which also tests for antigens, versus getting the diagnostic strep test: the former will give a fast result and is somewhat accurate, but won’t always catch every case. The latter requires a throat culture and may take a few days to give results but is extremely accurate for diagnosing whether a person has the disease.
A third type of test, the antibody test, looks for the antibodies produced by the body after it has been infected. Antibody tests are useful for figuring out if a person has already had COVID-19.
Germany plans to use 9 million COVID-19 antigen tests per month, at a cost of about 5 euros ($5.90) each. In Germany, 329,453 people have been infected with COVID-19; cases there rose by 4,122 Tuesday. The Robert Koch Institute of Germany is recommending use of antigen tests in tandem with PCR tests. Italy, Canada and the U.S. have secured and plan to use millions of antigen tests for COVID-19. Airlines in Italy (Alitalia) and Germany (Lufthansa) are using antigen tests to guarantee flight safety.
Infection rates are high in The Netherlands at present. While testing capacity there is now 280,000 per week, the government hopes to increase weekly testing levels to 385,000 by next week, to close to 500,000 by December and to nearly 600,000 by February. Many people, even those who are asymptomatic, want to be tested, and it can take days to get a test. The government has restricted antigen tests to healthcare workers and teachers. Others must go on a waiting list.
France now does over one million tests per week. The French government allowed free testing, and the French complied, which has resulted in long lines and delayed results. Researchers there have responded by developing a swab-free test that gives results in 40 minutes. Italy now does 800,000 to 840,000 tests a week. Government adviser and University of Padua Professor Andrea Crisanti says Italy needs to test 2 million people per week to control spread of the virus.
Roche (Switzerland) plans to launch an antigen test by the end of 2020 that can be processed at a rate of up to 300 per hour on a machine in the laboratory, once samples are entered into the machine. According to Roche, the tests could be useful in nursing homes or hospitals to stop outbreaks quickly. Roche plans to produce 50 million of the new tests per month by early 2021.
Said a Roche spokesperson:
“The primary use case is the testing of symptomatic patients. The secondary use case is the testing of individuals suspected of infection … which could also include asymptomatic patients.”
Roche has another rapid test on the market as well. Test manufacturers Siemens Healthineers, Abbott Laboratories and Becton Dickinson also sell COVID-19 tests.
In Switzerland, new infections recently rose to about 1,500 after schools reopened. Officials there are working to verify the accuracy of rapid antigen tests. The Swiss federal health ministry plans to update their testing recommendations in November.
While Sandra Ciesek, director of the Institute of Medical Virology at the University Clinic in Frankfurt, Germany, notes that rapid antigen tests could be helpful for testing asymptomatic people who plan to visit a nursing home, she warns that the PCR test is still the “gold standard” and should be used for diagnosis when possible.
Disclaimer: This article does not provide medical advice. Do not take action based solely on this article and always consult with an appropriate healthcare professional. This article is purely for informational purposes.