What are the types of Coronavirus tests available in the world?

The Novel Coronavirus has pushed the world economy to a standstill and only those companies, that are essential to life, are running. And this includes the Healthcare industry. The Coronavirus Era ushered in a new age of health-tech. This makes it even important for them to keep developing their technology to fight the Coronavirus. The Union Health Minister has already said that India will be self-producing RT-PCR Kits. So, it has become important to know what types of Coronavirus tests are currently available in the world.

But is India ready for that kind of mass-technology? Here are some popularly used testing methods to find the Coronavirus:

Types of Coronavirus Tests

1. PCR (Polymerase Chain Reaction)

PCR tests are used to directly detect the presence of an antigen. This is different from checking the presence of the body’s immune response, or antibodies. In this test, doctors detect the viral RNA that can tell whether or not someone has the virus very early on. These viruses are present in the body before antibodies form or symptoms of the disease are present. Currently, these tests are for people at risk of developing severe COVID-19.

It’s worth noting that PCR tests can be very labour intensive. It has several stages at which errors may occur between sampling and analysis. False negatives can occur up to 30% of the time with different PCR tests. This means that they are more useful for confirming an infection than give the patient, an all-clear. When people get to know that they have the virus, they can isolate themselves, and prevent further infection.

Some popular PCR testing methods are:

a. Nasal Swab

It is as uncomfortable as it sounds! To collect the sample, a swab (like a bud) is inserted in the nostril. The doctor then moves it to the back of the mouth, about 6 inches in. He then rotates the swab in the nose and throat to collect secretions. Later, he removes and places it into a clean plate, for later analysis.

This method is widely popular for all kinds of respiratory diseases, COVID-19 being the latest one. The test typically takes four to six hours to run to yield results. It requires several steps and high tech testing equipment to detect even a trace of the virus.

Heath-tech companies are constantly trying to make it easier to use and give final results. Nasal tests are available as home kits too.

b. Saliva testing

The FDA recently authorized the first genetic test that uses saliva, rather than a nasal swab. But its availability is limited for now. Doctors are using it instead of the Nasal Swab test where a person has to spit into a vial. On a similar line, European scientists are developing an ultrasensitive laser sensor that detects coronavirus at the earliest point of infection from the saliva sample in minutes.

The testing currently needs the help of a medical professional, but the government will soon mass-produce it as home-tests.

2. Serological Testing

Coronavirus tests break into two broad categories. The first one was the PCR tests which checked for the virus. It saw if you're currently infected. The second test looks for antibodies to see if the Coronavirus had previously infected you. If you have built up an immune response, this test is likely to tell you how much you have recovered.

An antibody test or a serology test can tell if COVID-19 has previously infested you. It also tells if you have built up an immune response through antibodies. It won’t tell you who is infected. Because the body generates antibodies after a week or two. After this, the body clears the virus from the system. The test requires a blood sample because the virus is present in the respiratory tract, but the antibody is flowing through the blood.

Also, if public health officials can get knowledge of what percentage of the population is immune to the virus, it could help lift the social distancing restrictions on movement.

 3. Antigen Testing

Antigen testing technology is not widely proven to test the Coronavirus. But it has the potential to find any antibody flowing through the body.

Think of it as a home-testing kit. You put a body sample like, a throat swab or saliva onto a specially treated strip. It then uses colour or marker to say whether the novel coronavirus is present. This tool can be specifically applied if doctors can uncover what kind of a protein layer surrounds the virus. These likely would not replace PCR tests, which are the most reliable, but they would be a good first step. It would be similar to a home pregnancy kit.

The WHO even said:

These could potentially be used as triage tests to rapidly identify patients who are very likely to have COVID-19, reducing or eliminating the need for expensive molecular confirmatory testing.

The more, the merrier

As the Coronavirus has taken hold of the world, the more testing we do, the faster we will be able to prevent it. For this, we will need high-efficiency, low-cost technology to test for the virus. Both antigen and PCR tests require nasal swabs. But antigen testing is simpler and even primary care physician can conduct the diagnosis. Patients would also get results in less than an hour.