COVID-19: Black Swan or clumsy use?

ABSTRACT

"Black Swan" is an unexpected and catastrophic event characterized by three conditions the anomalous and exceptional value, the extreme impact, and predictability a posteriori. On many sides - by politicians, commentators, scientists - there have been attempts to give the COVID-19 pandemic event the meaning of Black Swan. In reality, one should wonder if the Black Swan was not, instead (or even), the way the epidemic was handled. In Italy, an unreasonable use of a two-step protocol - IgM/IgG anti-COVID followed by RT-PCR in the serologically positive only has caused considerable uncertainty, particularly relevant in measures for maintenance or readmission to work of health personnel. This protocol could be affected by serious uncertainties arising from the analytical limitations of the tests used. To quantify this defect, we evaluated the analytical specifications of serological tests under different prevalence conditions. In conclusion, although laboratory diagnostics represent a useful tool, it can only be used for epidemiological purposes and not to provide healthy pass.