Updates on Laboratory Diagnosis of COVID-19 infections

Abstract

Background: COVID-19, the disease caused by SARS-CoV-2, beginning in the late 2019 as an outbreak in Wuhan, China- now, became the world’s most feared pandemic among communities around the globe. While we are investing almost all our efforts to save us from the infection, the diagnosis, still at the end of about 2-years of dreadful pandemic, remains difficult for common people. Although, this is a notorious, but enveloped virus, and therefore, is easily destroyable with heat (so, cannot easily survive in the environment) and detergents (so, can be easily killed by applying soap and water), is now returning consecutively in waves of variants with increasing virulence and transmissibility. Because of new variants of the virus, diagnostic approaches to identify the virion as a whole (by cell culture) or in parts (by detecting antigens) or viral products (by detecting antibodies against significant antigens) becomes difficult. The currently available laboratory test methods are ranging from rapid tests at point-of-care (detecting viral antigen(s)) to the genome sequencing. In between, majority of the tests like electron microscopy and cell culture are not routinely practiced, because of their high-end costly equipment and set up. All of these tests have extensively different results due to unpredictably variable presence of the virus (and its products) in clinical specimens as well as costs among the brands and these limitations are now putting the healthcare professionals along with their patients in discomforts of unsatisfactory management. Yet, the rapid tests are widely practiced for screening purposes, followed by confirmation by real-time reverse transcriptase polymerase chain reaction (rtRT-PCR) tests. This is a simple and comprehensive review of the diagnostic approaches considering all relevant issues of the virus (SARS-CoV-2) and the disease (COVID-19) immunobiology with the publications available up to February, 2022.

J Monno Med Coll June 2022;8(1): 17-28