Coronavirus (Covid-19): What is it? What are the symptoms? How to diagnose?
Coronaviruses are a large family of viruses that are known to cause illness ranging from the common cold to more severe diseases such as Middle East Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS). A novel coronavirus (CoV) is a new strain of coronavirus that has not been previously identified in humans. In terms of their roots, coronaviruses are transmitted from animals to humans (zoonotic). Detailed investigations found that SARS-CoV was transmitted from civet cats to humans and MERS-CoV from dromedary camels to humans. Several known coronaviruses are circulating in animals that have not yet infected humans.
What are the symptoms of the coronavirus disease?
The novel coronavirus 2019 (SARS-CoV-2) was first identified as an epidemic of respiratory diseases with similar complaints among many people in Wuhan city of China. Patients diagnosed with SARS-CoV-2 often applied to healthcare clinics with severe respiratory failure. The main symptoms of the disease are fever, cough, sore throat and respiratory failure.
Which tests can be used for diagnosing the coronavirus disease?
Since the symptoms of the coronavirus (Covid-19) disease are very similar to influenza, it is hard to diagnose coronavirus (Covid-19) by just the clinical picture. Thus, certain laboratory tests are needed to distinguish suspicious coronavirus (Covid-19) cases.
Today, there are 2 main methods used in the identification of the Covid-19 virus, which are not mutually exclusive, but do complement each other. To summarise, the PCR method is used in early diagnosis of infection, while antibody tests are used for diagnosis after the first week of infection. Antibody tests also identify if you had the illness, after your body overcomes the virus.
1- As the gold standard of the coronavirus tests (tests with the highest rate of accuracy), the PCR method identifies the existence of the virus in the body. The ideal sample for the PCR test is the swap taken from the areas of the body where the viruses settle (upper and lower respiratory tract for the coronavirus). By studying the sample in a special instrument, molecules in the sample are replicated and existence of virus molecules is searched. PCR tests play an important role in the early diagnosis of coronavirus infections. Governments take the PCR test results as the basis in the determination of the official number of cases.
2- The second method used to detect coronavirus is antibody tests. Basically, these tests aim to detect the presence or absence of the virus by identifying specific antibodies the body has developed against the virus. The ideal sample for antibody tests is the blood sample. Any potential antibody contained in the blood sample is expected to react with the test, as a result of which a visible marker is expected to appear on the test cassette. Antibody tests are divided into two as ELISA and rapid diagnostic tests. Although ELISA tests are more reliable, they take longer and they are required to be applied under laboratory conditions. On the other hand, rapid diagnostic tests produce results in a very short time or 10 or 20 minutes, in contrast to ELISA. They identify existence of the virus in the body by measuring the antibodies that the body has developed against the virus. Thus, thanks to the antibody tests, you can find out not only if the virus is currently present in your body, but also whether you previously had the disease.
Please refer to our catalogue for the visual comparison between the 2 test methods.