A study analyzed SARS-CoV-2 viral loads in upper respiratory specimens from 18 infected patients in Zhuhai, China, including 4 with secondary infections. The study found that viral loads peaked around 10 days after symptom onset, with higher levels in nasal swabs than in throat swabs. The viral load pattern in SARS-CoV-2 patients resembled that of influenza, differing from SARS-CoV. An asymptomatic patient had a viral load similar to symptomatic patients, suggesting asymptomatic or minimally symptomatic individuals may transmit the virus. Transmission could occur early in the infection, indicating that case detection and isolation strategies may differ from those used for SARS-CoV. The study highlights the need for better data to understand transmission dynamics and improve screening practices. The findings support the possibility of transmission from asymptomatic individuals and suggest that viral load may not always correlate with culturable virus. The study was conducted between January 7 and 26, 2020, involving 14 patients who had recently returned from Wuhan and 4 with secondary infections. Patients with severe illness had lower Ct values in nasal and throat swabs compared to those with mild-to-moderate illness. The study underscores the importance of monitoring viral load and considering asymptomatic transmission in public health strategies.A study analyzed SARS-CoV-2 viral loads in upper respiratory specimens from 18 infected patients in Zhuhai, China, including 4 with secondary infections. The study found that viral loads peaked around 10 days after symptom onset, with higher levels in nasal swabs than in throat swabs. The viral load pattern in SARS-CoV-2 patients resembled that of influenza, differing from SARS-CoV. An asymptomatic patient had a viral load similar to symptomatic patients, suggesting asymptomatic or minimally symptomatic individuals may transmit the virus. Transmission could occur early in the infection, indicating that case detection and isolation strategies may differ from those used for SARS-CoV. The study highlights the need for better data to understand transmission dynamics and improve screening practices. The findings support the possibility of transmission from asymptomatic individuals and suggest that viral load may not always correlate with culturable virus. The study was conducted between January 7 and 26, 2020, involving 14 patients who had recently returned from Wuhan and 4 with secondary infections. Patients with severe illness had lower Ct values in nasal and throat swabs compared to those with mild-to-moderate illness. The study underscores the importance of monitoring viral load and considering asymptomatic transmission in public health strategies.