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Revista Argentina de Salud Pública

Print version ISSN 1852-8724On-line version ISSN 1853-810X


SALMERON, Mariana B.. Overestimation of COVID-19 cases based on results of the rRT-PCR for detection of SARS-CoV-2. Rev. argent. salud pública [online]. 2021, vol.13, suppl.1, pp.12-12. ISSN 1852-8724.

The detection of the viral genome using the real-time reverse transcription polymerase chain reaction (rRT-PCR) technique to detect the severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) is considered as a reference for the case definition of coronavirus disease 2019 (COVID-19), laboratory confirmed. However, detecting a viral genome is not the same as diagnosing a disease, and its detection sensitivity may exceed clinical significance. In Microbiology, the ranking of a positive result depends on factors such as clinical/epidemiological context, sample collection site and, in many cases, quantification of the pathogen. A fundamental parameter of rRT-PCR is the threshold cycle. The classification of a person as a confirmed case depends on its interpretation. On the other hand, the predictive values of a test vary according to the prevalence of the pathology sought. Given that the positive tests obtained in different scenarios are considered equivalently as confirmed cases, regardless of signs and symptoms, there may have been an overestimation of the real cases of COVID-19 disease, mainly based on tests carried out in the general population. It is essential to train personnel and carry out quality controls in diagnostic laboratories, as well as define threshold cycle cutoff levels that are predictive of infectivity in reference centers, to minimize the impact of false results on society.

Keywords : SARS-CoV-2; COVID-19; Real-time Polymerase Chain Reaction; False Positive Reactions; Predictive Value of Tests.

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