157 CMAAO CORONA FACTS and MYTH Viral Load
Dr K Aggarwal
With inputs from Dr Monica Vasudev
992: DG alert: A study published in The American Journal of Pathology showed that non-hospitalised patients with COVID-19, with less severe symptoms, have a higher SARS-CoV-2 viral load (VL) than hospitalised patients with more severe symptoms.
In a cohort of 205 patients treated at a tertiary care centre in New York City who were tested using both qualitative RT-PCR and quantitative RT-PCR to obtain diagnostic SARS-CoV-2 VL at initial presentation, Kimon V. Argyropoulos, New York University Langone Health, New York, New York, and colleagues found that diagnostic viral load (VL) was significantly lower in hospitalised patients than in patients not hospitalised after adjusting for age, sex, race, body mass index, and comorbidities.
Higher VL was associated with shorter duration of symptoms in all patients (P< .001). Among hospitalised patients only, higher VL was also associated with shorter duration of symptoms (P = .002) and with shorter hospital stay (P = .013). No significant association was noted between VL, admission to intensive care unit, length of oxygen support, and overall survival.
Non-hospitalised patients were overall younger (median age, 45 vs 60 years; P< .001). The median duration of symptoms from symptom onset to nasopharyngeal swab collection in the hospitalised group was 5 days compared with 3 days in the non-hospitalised group (P = .017).
In the hospital triage setting, the information from the viral load can be utilised to determine which patient would receive a negative pressure room.
In the outpatient setting, clinicians can utilise viral load as a quantitative metric to reinforce the importance of self-isolation and face coverings to reduce the risk spreading the infection.
Comments: The virus becomes non replicative by 9 days. In hospitalised patients the viral load in this study was done later in the disease course and hence coulc have been lower.
https://www.ahajournals.org/doi/pdf/10.1161/CIRCULATIONAHA.120.049252 SOURCE: Circulation and The American Journal of Pathology