COVID-19 'asymptomatic' patients: an old wives' tale.

INTRODUCTION: A novel virus, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) was reported via nucleic acid identification in December, 2019. 'Asymptomatic cases' have arised as an obstacle for an accurate diagnosis, curtailing the elimination of the ongoing pandemic. AREAS COVERED: In this review, we analyze the definition of symptoms and the principles of diagnosing COVID-19. Also, we explore the major reasons for cases presenting a phenotype with mild symptoms. Host, viral and environmental aspects for a COVID-19 leading to mild symptoms are being highlighted. A final aspect regarding a rational asymptomatic COVID-19 is presumed. EXPERT OPINION: Diagnosing a pandemic via a sole test can be risky. Epidemiological administration should be more accurate and precise, not only for the societal pandemic levels and following policies, but for the same scientific community, that studies SARS-CoV-2 and its mutants. Several other issues should be answered before analyzing human genome for the asymptomatic scenario.