Emerging clinically tested detection methods for COVID-19.

At the time of writing, there were 486 761 597 global cases of COVID-19 with 6 142 735 confirmed deaths (World Health Organization, 4 April 2022). According to the scarcity of information about estimation of cases with mild or no symptoms, it is suggested that they could represent 25-80% of all infections. The majority of these cases remain untested, although they are infective. The molecular diagnosis of COVID-19 is based mainly on quantitative reverse transcription PCR. However, this approach faces several challenges related to the shortage of resources and people who are adequately trained to run the tests. Alternative testing methods, targeting effectively several viral compounds at different stages of the infection, have quickly emerged. However, universal systems that are specific, sensitive, affordable, easy, portable and scalable are still warranted. In this review, a comprehensive compilation of the methods available is provided.