Study: Viral load of COVID-19 patients, deaths declining

Editor's Note

This study presented September 24 at the European Society of Clinical Microbiology and Infectious Diseases Conference on Coronavirus Disease finds that the initial SARS-CoV-2 viral load (VL) in nasopharyngeal samples has been decreasing as the pandemic progresses.

The researchers from Wayne State University/Detroit Medical Center, Detroit, Michigan, also found that the decline in VL was linked to a decrease in death rate.

The researchers analyzed VLs of SARS-CoV-2 from 708 hospitalized patient nasopharyngeal swabs from April 4 to June 5. During the week of April 4, 48.7% of COVID-19 patients had an intermediate VL, compared to 25.5% each in the low and high VL patient samples. By the fifth week of the study, 70% of positive COVID-19 swabs were in the low VL category.

This drop in viral production coincided with a decrease in patient deaths—45% of high VL patients died, compared to 32% of medium VL patients, and 14% of low VL patients.

By week 5, about 12% of patients had high VLs and 18% had intermediate VLs. By week 6, no patients had high VLs.

The researchers concluded that the downward trend in VL may indicate that the pandemic is becoming less severe.