What Coronavirus Tests does the World need to Track the Pandemic?

LAGOS (Capital Markets in Africa) – The imperative to “test, test, test” has become a slogan of the coronavirus pandemic since it was voiced last month by Tedros Adhanom Ghebreyesus, head of the World Health Organization. But the simple goal continues to elude even well-off countries that are struggling to track the spread of the virus among their populations.

Germany and South Korea have led the way in rolling out tests on a large scale, but the UK and US have been laggards. The greater the delays, the more prolonged the uncertainty over the size of the virus threat. As the hunger for diagnosis grows, as testing kits are rejected and impatience with government mounts, we look at the available technologies, their potential, and limitations.

What tests are available for coronavirus infection?
There are two main types. The first, an antigen test, detects the presence or absence in the body of the new coronavirus, which causes the disease Covid-19. The second, an antibody test, looks for signs that someone has been infected in the past by searching for an immune response.

Since Chinese scientists in mid-January published the full genetic code of the virus — officially known as Sars-CoV-2 — laboratories anywhere in the world have been able to use antigen testing to identify its genes in samples from patients. They use a procedure called polymerase chain reaction (PCR) that has been standard practice in labs for 30 years.

PCR samples can come from several different sites in the patient. Simplest is the nasal swab taken from well inside the nose. The back of the throat is another option. For patients in hospital, a sample from the lower respiratory tract may give the best results. Antigen testing reveals whether someone has a current infection and could, therefore, pass Covid-19 on to others.