Acad Emerg Med. 2021 Jan 22. doi: 10.1111/acem.14217. Online ahead of print.
INTRODUCTION: The ongoing COVID-19 pandemic has led to devastating repercussions on healthcare systems worldwide. This viral infection has a broad clinical spectrum broad (ranging from influenza-like disease, viral pneumonia, hypoxemia to ARDS requiring prolonged ICU stays). The prognostic impact of measuring viral load on nasopharyngeal swab specimens (by RT-PCR) is yet to be elucidated.
METHODS: Between March 3rd and April 5th , 2020, we conducted a retrospective study on a cohort of COVID-19 patients (mild or severe disease) who were hospitalized after presenting to the emergency department (ED) and had at least one positive nasopharyngeal swab during their hospital stay. We led our study at the University Hospitals of Strasbourg, in the Greater East region of France, one of the pandemic's epicenters in Europe.
RESULTS: We have collected samples from a cohort of 287 patients with a confirmed diagnosis of COVID-19 who were included in our study. Nearly half of them (50.5%) presented a mild form of the disease, while the other half (49.5%) presented a severe form, requiring mechanical ventilation. Median viral load on the initial upper respiratory swab at admission was 4.76 (3.29-6.06) log10 copies/reaction. When comparing survivors and non-survivors, this viral load measurement did not differ according to subgroups (p=0.332). Additionally, we have found that respiratory viral load measurement was predictive of neither in-hospital mortality (AOR=1.05, 95%CI: 0.85-1.31, p=0.637) nor disease severity (AOR=0.88, 95%CI: 0.73-1.06, p=0.167).
CONCLUSION: Respiratory viral load measurement on the first nasopharyngeal swab (by RT-PCR) during initial ED management is neither a predictor of severity nor mortality in SARS-CoV-2 infection. Host response to this viral infection along with the extent of pre-existing co-morbidities might be more foretelling of disease severity than the virus itself.