Toward to establish selection criteria for rapid serological tests for COVID-19

"COVID-19, the new pandemic is associated to SARS-CoV-2 virus infection. Social distancing and the testing have been the principal measures that have shown to be effective for the reduction of critical cases. Although the gold standard for diagnosis of COVID-19 is the RT-PCR, rapid serological tests could also be used for prevalence studies, and for epidemiological monitoring. In order to characterize the humoral immune response, we analyzed eight immuno-chromatographic test and one ELISA test, as a verification or secondary validation analysis used positive and negative control serum samples. Sera from negative and positive individuals [asymptomatic or symptomatic individuals, outpatient or inpatientor (intensive care unit)] were analyzed, and the following results were found: of all these rapid tests, only 4 exhibit clear banding patterns for IgG and two of these also showed results for IgM (only in a few symptomatic patients). Instead, with an ELISA test a preferential recognition was observed for symptomatic patients who were critically ill, whereas in asymptomatic individuals it did not show more than 25% of positivity. Understanding and validating molecular and serological tests are an essential component for the design of public health measures to response to the pandemic.
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