Health and Beyond Foundation

Covid 19 Diagnostic Tests

(Prof. Alka Gogate, 1st May 2020)

The novel Corona virus is a RNA virus and highly transmissible. There are 2 types of tests to detect the presence of the virus in the body.
The  antigen test, which detects the virus particle. The samples for this test are from nasal and throat swabs. This usually comes positive by the 5th day of infection
The antibody test which detects the presence of antibodies to the virus.   Antobody tests are done through a blood test. The antibody test shows the immune response by the body against the virus. The tests usually detect two types of antibodies. One, called IgM, is typically produced about a week after infection and could identify patients who may still be infected. This IgM is detected by day 7 of the infection.  Levels of IgM begin to wane as the body makes another type of antibody called IgG, which can persist for longer periods of time.. By Day 10 of infection, immunoglobin G or IgG is shows up. This presence of IgG suggests that the person has been infected for a long time.