COVID-19 Viral Load and Clinical Outcomes: Is There a Correlation?

Over the course of the pandemic, the term, viral load, has been bandied about as clinicians and investigators try to determine its significance and place in understanding COVID-19 and beyond. 

Lizzy Hastie, MD, reminds clinicians there are a whole host of benefits of knowing viral loads in patients including transmissibility, their prognosis, eligibility of treatments, and aids in studying investigational therapies.

Still, the evidence we have presently is confounding, explained Hastie who is a first year infectious diseases fellow at UCSD. “The data we have now is pretty conflicting about the significance of the viral load. Some studies have shown it correlates pretty well with outcomes, others haven’t,” Hastie said. “Some have shown correlations with age and other risk factors, and symptoms so we really wanted to tease it out.”

Hastie and her coinvestigators wanted to look at a new testing technology, Droplet Digital PCR, and to explore the associations between SARS-CoV-2 viral load and patient symptoms, demographics, and clinical outcomes.

Her study was presented as a poster, “Association Between SARS-CoV-2 Viral Load and Patient Symptoms and Clinical Outcomes Using Droplet Digital PCR,” at IDWeek 2022, held October 19-23, 2022, in Washington, DC.

For their findings, the investigators did confirm that a higher viral load was predictive of symptomatic disease and in-hospital mortality. These findings suggest that early viral control may prevent progression of disease.

Hastie sat down with Contagion who offered some insights into their study including the methodology, the technology, and their results.