- Viral loads seems to be higher soon after the symptom onset, with higher viral loads detected in the nose than in the throat.
- The results suggest a potential transmission potential by asymptomatic or minimally symptomatic patients, as the viral load in the asymptomatic patient was similar to the symptomatic ones.
These data come from analysis of a study monitoring SARS-CoV-2 viral loads in upper respiratory samples obtained from 18 patients in China. A total of 72 nasal swabs and 72 throat swabs were analyzed, with 1 to 9 sequential samples per patient. One patient never had symptom.
Zou L., Ruan F., Huang M., et al. (March 19, 2020) SARS-CoV-2 Viral Load in Upper Respiratory Specimens of Infected Patients. The New England Journal of Medicine, 382(12):1177-1179. DOI:10.1056/NEJMc200173