Laboratory Diagnosis of Novel Coronavirus Disease 2019 (COVID-19): A Review

Abstract

A spate of pneumonia cases caused by A novel Coronavirus called severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) was observed in Wuhan, Hubei province of China in late 2019. The outbreak termed COVID-19 has spread rapidly almost throughout the world with a case fatality of approximately 6.9%. The disease spreads by droplet infection from person to person. Early diagnosis is the key for prompt management of cases and control of the spread of the virus. Currently, real-time reverse transcription polymerase chain reaction (rRT- PCR) for the detection of unique sequences of the viral genome is the gold standard for COVID-19 testing where the N, E, S and RdRp (RNA-dependent RNA polymerase) genes are targeted using upper and lower respiratory tract specimens. The rRT-PCR is labor intensive, severely constraining the capacity for quick turnaround time (TAT) from sample collection to results transmission particularly in resource limited settings. Consequently, laboratory testing of suspected cases might be characterized by long wait periods. The exponential increase in demand for tests, coupled with inherent shortage or scarcity of laboratory resources dictates the need to provide for all that is required for effective diagnosis in the laboratory. Also, whether other materials, such as blood, urine, stools, saliva and throat washing, will become valid alternatives has not been unequivocally defined so far. The development and availability of serological assays and point of care molecular testing assays are potentially viable opportunity for purposes of diagnostics and epidemiologic surveillance, although more information is needed on accuracy and reliability of these portable immunoassays as non has been licensed for use in the country according to the Nigerian Centre for Disease Control (NCDC). Majority (80%) of these infections remains asymptomatic and are the major drivers of the spread of the infection around the world. With the perception of our experiences in recent months, it is clear that COVID-19 may have come to stay and we might be living together with this virus for quite a long time. Thus, our level of surveillance (using laboratory testing) and responsiveness against the emergence over burdened local outbreaks must be maintained at the highest possible levels with mitigation strategies to limit the spread of the disease.