There are different methods of testing that are experimented to trace Corona Virus infection in the human body.
Of them the two prominent tests being:
1) RT-PCR (Reverse Transcription-Polymerase Chain Reaction).
2) Anti-body tests.
RT-PCR (Reverse Transcription-Polymerase Chain Reaction):
This method of testing is pronounced by the health ministry as a ‘gold standard frontline test’ for COVID-19. In this test, a nasal/throat swab sample is collected from the patient. The extraction of RNA or ribonucleic acid, which is a genetic material for the virus is done. If the genome matches the genetic sequence of the SARS-CoV-2 virus, then it is deemed positive. If the actual sample doesn’t carry a virus, or it wasn’t administered properly then it turns negative.
This method of testing came into effect after the ‘rapid anti-body tests’ showed up unreliable results.
These tests are also known as serological tests, used to find the traces of the virus in the body, if present. Blood samples are collected and used to find anti-bodies. Anti-bodies are generally produced to resist the immune system to fight against the invasion of antigens into the body. These antibodies chemically combine with substances that the body identifies as alien, like bacteria, viruses, and any other foreign substances in the blood.
This is an indirect method of testing. It cannot detect the presence of a virus in the body but can determine if the immune system has encountered it. The anti-bodies are shown up in between 9-28 days after infection but by this time the disease can be spread by the infected person, if not isolated.
From the above-mentioned tests, to determine the virus intrusion into the human body through blood, an antibody test is done. By collecting the blood samples from the patients, the type of blood and anti-bodies, if any, produced can be examined.
A new, preliminary study that has been recently conducted by researchers from Southern University of Science and Technology, China, have found a potent relationship between blood type and risk of hospitalization due to COVID-19 virus. According to research, people with ‘A’ blood type are more prone to the risk of getting infected than people with other types of blood groups.
A team of researchers initially looked at the blood group distribution among 2173 patients admitted to hospitals with COVID-19, a new coronavirus disease. These tested blood groups are compared with that of the general population and found that people with blood type ‘A’ were significant in the proportion who were hospitalized with COVID-19 than among the general population.
They also found that people with blood type ‘O’ have a significantly lower risk of infection in comparison with non-O blood groups.
However, it is important to stress that the researchers refer to the risk of need to hospitalization due to COVID-19 rather than the risk of contracting with a disease that leads to death. This is because the researchers looked at data of patients with severity in infection who require hospitalization but not those with mild symptoms responded to home care.
In entirety, it doesn’t mean that people with ‘A’ type blood group have added cause to concern, while those with ‘O’ type blood group can exhale in relief. It is difficult to understand this conclusion without establishing causal links between the coronavirus and ABO blood group antigens. Further scientific research is required to substantiate these claims as the research was conducted among a limited group of people and the blood group distribution varies by country.
Role of blood type in respiration:
Respiration is a process in every living organism which involves the production of energy typically by intake of oxygen and release of carbon dioxide by oxidation of complex organic substances.
Respiration takes place through the lungs and the blood absorbs the inhaled oxygen from the air in the lungs.
The respiratory system (lungs) is mainly affected due to the coronavirus infection. Patients who are more susceptible to respiratory failure with pneumonia or respiratory distress syndrome are mostly driven to mortality. However, this is the case with less than 10 percent of people who got infected with SARS-CoV-2.
Early clinical reports suggest that the ABO blood group system is involved to determine the susceptibility to COVID-19. Further analysis showed that A-positive blood group participants had a 45% increased risk of respiratory failure, while individuals with O-type blood group were at a 35% decreased risk of respiratory failure.
Role of blood type in immunity:
Immunity is the ability of an organism to resist a certain infection or toxin (caused by the foreign body that invaded into the body) by the action of specific antibodies or sensitized white blood cells against them.
It a fact that some people don’t know their blood type and even if they know they may be unaware that the type of blood makes more prone to certain medical conditions. Antigens are a type of proteins on RBCs and based on their type, blood will be categorized into Type A, Type B, Type AB or Type O. The ‘+’ and ‘-‘ signs next to your type of blood come into play based on the Rh factor present on the red blood cells.
An increased or decreased host susceptibility to many infections is due to differences in blood group antigen expression. By serving as receptors and/or coreceptors for microorganisms, blood groups can play a direct role in infection.
The COVID-19 virus is likely to affect more in people with low immunity which is seen mainly in infants and aged people. The immune system in children will be in the maturing stage and learning to adapt to this galaxy of infectious agents whereas in the elderly, especially in people with existing conditions such as diabetes and cardiovascular disease will have an inherent malfunctioning in the immune system.
The viruses have a signature to show up on their surface called antigen and the immune system kicks into action by spotting these antigens thereby producing antibodies and hence the immunity forms basis to be the severity of being prone to this viral infection.
Although there are links between the immune system and blood group phenotypes, antibodies are produced by the cells of the immune system and not by blood type loci. Further clinical research may be required to validate the connection of blood type and immunity in the human body.