Published January 11, 2021, 12:00 am

The importance of COVID-19 testing and Screening

For the early identification, treatment, diagnosis, reporting, and isolation, timely and correct testing is a significant prerequisite.

Coronavirus testing or screening can directly impact:
• Effectiveness of infection prevention
• Effectiveness of pandemic control

According to the WHO, testing of the coronavirus infection is the utmost need of the world. WHO has delivered a message to the whole world to focus on frequent testing and repetitive screening.

Coronavirus testing
Currently, health providers are using two types of tests for the diagnosis of coronavirus:
• Antigen test
• Antibody test

An antigen test or RNA test is for confirming the virus's presence in the sample or specimen.

Antibody test or serological test is the test for confirmation of antibodies in the body to fight infection.

Both of these tests have their risks and benefits with multiple variations. 

RNA test can detect the infection even before the production of antibodies for fighting the virus. This test's reliability has almost 75% accuracy, detecting the virus even before the antibody test. This test requires swabs of 6-inches in length.These swabs pass through the nasal passage through one of your nostrils. In the nostril, this swab is rotated for about 15 seconds to collect the mucus sample. Then this swab goes into lab testing using PCR testing for generating the result.

While antibody tests require the blood sample of the person to check for antibodies present in the blood, the presence of IgM antibodies can indicate the exposure of the virus. While the presence of IgG antibodies indicates a later stage of the infection. IgG represents the later stages of the infection, which is almost the 14thday of the infection. Antibody test requires some time for yielding the results after coronavirus exposure.

Why is testing vital?
Identification of infection source:
Testing or screening for coronavirus infection is vital. Testing helps with identifying infection sources and helps in facilitating the overall planning of infection control and prevention.

Testing or screening is the central source for the identification of infection. Itprovides measures for control or infection prevention.

In China, health care facilities tested several infectors for identifying or confirming the presence of the virus in them. On the basis of screening and mass testing, China took control over the pandemic in a short time. Chinese health care facilities adopted measures to test the target, tracing close contacts, epidemiological testing, and quarantining. These measures were effective in preventing the spread of the disease.

Early diagnosis and treatment:
Testing also helps with early diagnosis and treatment for reducing the mortality rate and improving the prognosis. For diagnosis of the coronavirus infection, virus testing or screening is the only diagnostic criterion.

Suppose a person gets testing or screening on time. In that case, he can improve his infection prognosis and reduce the mortality rate due to infection.

According to the National Health Commission statistics, China decreased the proportion of coronavirus infections from 38% to 18% in Wuhan with early detection and effective treatment after hospital admission. 

Categorization of the patients:
In coronavirus disease, different patients can suffer from the different intensity of the infection. For instance, some patients will have influenza-like symptoms or mild symptoms, while some patients can have severe conditions.

Testing and screening help with the categorization of the patients according to their health conditions. Categorization of patients helps with effective interventions and treatments. It determines the level of treatment that the patient needs according to the symptoms and severity of the disease.

Screening strategy in China
Coronavirus pandemic started in China. 

China regulated their facilities for effective testing and screening. With time, China discovered cost-effective or low-cost testing for this infection. The cost-effective screening showed exceptional results in infection control. With different strategies, China instantly improved its efficiency and capacity in testing for coronavirus.

According to the statistics, Hubei province is capable of testing more than 10,000 suspects of infection in one full day. Along with swab testing, nucleic acid testing can also yield results within two hours of the testing. Simultaneously, China took measures to guarantee cost-effective testing for several potential coronavirus infectors.

The whole world is now focusing on measures to build low-cost machines and testing equipment for coronavirus testing. This will increase the diagnosis rate andhelp the individuals in early treatment for these patients.

Concerns with the coronavirus testing and screening
There are a few concerns with coronavirus testing and screening. 
One of the main concerns regarding coronavirus testing is contact investigation. In the contact investigation, health care practitioners have to test all the individuals who came in contact with the positive infection patient. This practice needs a lot of hard work and time. Most of the time, the contacted patients' data is uncertain or unavailable, making it difficult to conduct the testing and screening of suspected individuals. The contact investigation is the need of the time to minimize the infection spread, but it seems too difficult to practice. Contact infection is a vital reason for the infection spread.

Another significant test or screening for coronavirus infection is testing patients who already had an illness. This test confirms the presence of the virus even if the patient has unknowingly recovered from the infection.

When a person is infected with a certain virus, the patient's immune system stays unfamiliar with the foreign object. With time, the virus tends to multiply and reproduce multiple copies in the human body. This replication of the virus can yield several manifestations of the disease like cough, SOB, fever, and pain, which triggers the individual's immune response.

During an immune response, our bodies produce antibodies. These antibodies are evidence for a patient about his past infection or exposure. Confirmation of an individual for his disease can help the health officials and health systems to understand the level of community immunity. Suppose a large percentage of immunity exists in the community. In that case, it refers to herd immunity, which is profitable for the coronavirus prognosis.

Knowing about the patients who have recovered from the infection and immunity can work safely in the work settings, maximizing public safety. 

This seroconversion process shows the conversion of a healthy individual to infection and then recovery from the infection leading to immunity. Coronavirus testing and screening can confirm such patients to transplant their plasma having antibodies to infected patients.

Significance of coronavirus testing in employees
Coronavirus screening can:
• Help the employers to maintain a safe working capacity for their return to work
• Inform the employees for creating their plans and decisions to continue their work
• Identify the patients who don’t show any symptom for preventing the large loss of workforce
• Give all the significant information which is necessary for acting quickly if the employee becomes infected.

Surface testing
Surface testing is another type of testing, which involves screening high touch surfaces in workplaces or facilities. Surface testing uses RT-PCR technology,which determines the presence of coronavirus. The surface testing involves fomites and all the hard surfaces.

Surface testing provides the other layer of accountability, prevention, accountability, and the ability to have containment measures and proactive control. 
We can conduct surface testing, either pre or post the disinfection. Health care associations recommend that surface testing be a regular preventive measure regularly after performing the preventive disinfecting regimen.