Background: Upper respiratory tract specimens are widely applicable for the diagnosis of COVID-19. To date, no study has analyzed the actual viral loads in upper respiratory tract and its relationship with the severity of lung lesions, Ct value of RT-PCR and transmission capacity in COVID-19 patients.Methods: We retrospectively enrolled nine COVID-19 patients. Clinical data and close contacts of these patients were investigated. Respiratory samples were tested for SARS-CoV-2 with both normal RT-PCR and droplet digital PCR.Results: All the COVID-19 patients complicated with pneumonia. Viral loads in nasopharyngeal swabs were accurately quantified, and they had no direct correspondence with the severity of lung lesions. The Cycle Threshold (Ct) value of RT-PCR was approximately consistent with the absolute quantification of digital PCR. The spearman correlation coefficient between them was -0.952 with P value < 0.001. Close contacts of patients with very low viral load or no detected virus were not infected.Conclusions: Viral loads in nasopharyngeal swabs, could not predict the severity of lung lesions revealed by CT in COVID-19 patients. The infectious capacity of patients with low or absent viral load in upper respiratory tract was relatively weak, and wearing mask might be helpful for lower its spread.

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BACKGROUND Although internet healthcare services originated in the 1960s, it was only upon the occurrence of the COVID-19 pandemic that the demand for these online services grew at unprecedented rates. To meet the demand, the internet healthcare environment developed rapidly during the pandemic. OBJECTIVE This study aimed to identify the current status of internet healthcare service use in China and explore users’ perspectives on the barriers and facilitators that influence its use. METHODS We conducted 58 semi-structured interviews with people across China between September and October 2022. The 58 interviewees were selected by snowball sampling and described their own experiences of internet healthcare services utilization. RESULTS Online registrations, online consultations with physicians, medical information inquiries, and online payments were the main functions of internet healthcare services used by Chinese residents. The factors positively associated with the use of internet healthcare services were the time-saving characteristic of such services, the COVID-19 pandemic, the distance from the hospital, and e-related knowledge. The factors negatively associated with the use of these services were preference for conventional consultations, disease treatment urgency, cost of internet healthcare services, and doubts about the safety and privacy of the platforms and about the diagnosis made online. CONCLUSIONS Internet healthcare services seem to play the role of an alternative, not a substitute, to conventional healthcare services in China. Our study could provide relevant, up-to-date information that healthcare providers and healthcare policymakers can use when devising relevant measures to improve internet health care service. Related stakeholders should provide clear operation instructions to improve accessibility, and involved authorities should thoroughly regulate these online services to ensure their quality, their safety, and patients’ privacy.