Recurrence of SARS-COV-2: Facts and Myths
The severe acute respiratory syndrome‐related coronavirus‐2 (SARS‐CoV‐2) reactivation or reinfection will be an enduring and disquieting problem. SARS‐CoV‐2 replication in the host reaches its peak in the first week of infection, decreasing rapidly afterwards, due to the development of some levels of immunity. Yet, the infection seems to follow an uncustomary course in some individuals, reactivating after the apparent resolution of symptoms. Reinfection is a major public health concern in terms of global morbidity and possibly mortality. Several thoughts have been raised due to the “Retest Positive” for SARS‐CoV‐2 from “recovered” coronavirus disease‐19 (COVID‐19) patients. At the moment, it is difficult to discriminate if the positive nasopharyngeal swab results are due to real recurrence of COVID- 19 infection or intermittent shedding of RNA fragments, especially in asymptomatic subjects. On the other hand, it cannot be excluded that truly negative discharged patients suffered reactivation or were re-infected with another COVID-19 strain, especially in elderly or in subjects with comorbidities. A report from the largest cohort study confirmed that more than 10% of patients clinically recovered from COVID-19 infection had re-positive RT-PCR at nasopharyngeal swab during post-discharge follow-up, and most of these subjects were asymptomatic at the time of recurrence. The proportion of re-positive patients among discharged COVID-19 patients varied from 2.4 to 69.2% and lasted from 1 to 38 days after discharge, depending on population size, age of patients, and type of specimens.