Viral Load Kinetics of SARS-CoV-2 Infection in First Two Patients in Korea

A number of interesting observations regarding SARS-CoV-2 were made in this paper which have implications regarding treatment.

"Unlike SARS-CoV infection,8 we found that viral load was highest during the early phase of the illness (3–5 days from first symptom onset, fever and myalgia were the only symptoms in Patient 1) and continued to decrease until the end of the second week. While she developed cough as well as shortness of breath and infiltration appeared on CXR at the end of first week of illness, the viral load already started to decrease at this phase. This may have a very important implication to determine the optimal time point for antiviral treatment intervention to prevent progression to severe disease. Second, the virus was detected from LRT specimens even before the development of LRT symptoms (cough, shortness of breath, and oxygen requirement) or visible infiltration on CXR. This may suggest that although the patient does not complain of any LRT symptoms, the virus is already there and causing insidious pathology, ultimately leading to LRT symptoms and chest infiltration later. However, the viral load starts to decrease in both URT and LRT specimens at the same time, which may puzzle the clinicians. Third, unlike in MERS-CoV revealing higher concentration of virus in LRT specimens, viral loads were similar in both URT and LRT specimens. Fourth, low concentration of genetic materials, especially E gene, was detected in urine and stool from the end of the first week until the patient recovered from the infection. However, rRT-PCR results did not meet the criteria for SARS-CoV-2 positivity. Further studies need to be performed in non-respiratory specimens such as urine and stool samples."

https://jkms.org/DOIx.php?id=10.3346/jkms.2020.35.e86