ABSTRACT
The dynamics of SARS-CoV-2 replication and shedding in humans remain poorly understood. We captured the dynamics of infectious virus and viral RNA shedding during acute infection through daily longitudinal sampling of 60 individuals for up to 14 days. By fitting mechanistic models, we directly estimate viral reproduction and clearance rates, and overall infectiousness for each individual. Significant person-to-person variation in infectious virus shedding suggests that individual-level heterogeneity in viral dynamics contributes to superspreading. Viral genome load often peaked days earlier in saliva than in nasal swabs, indicating strong compartmentalization and suggesting that saliva may serve as a superior sampling site for early detection of infection. Viral loads and clearance kinetics of B.1.1.7 and non-B.1.1.7 viruses in nasal swabs were indistinguishable, however B.1.1.7 exhibited a significantly slower pre-peak growth rate in saliva. These results provide a high-resolution portrait of SARS-CoV-2 infection dynamics and implicate individual-level heterogeneity in infectiousness in superspreading.
ABSTRACT
Objective To investigate the effects of postoperative adjuvant chemotherapy (CT) and chemoradiotherapy (CRT) or radiotherapy(RT) for Ⅰ b-Ⅱ a cervical cancer with risk factors.Methods From March 1995 to June 2010,there were 137 patients underwent radical hysterectomy and systematic pelvic lymphadenectomy for stage Ⅰ b-Ⅱ a cervical cancer admitted at Peking University First Hospital.These patients had risk factors,intermediate risk factors including bulky tumor (＞4 cm),lymph vascular space invasion,deep stromal invasion; high risk factors including positive surgical margin,parametrial invasion,lymph node involvement.Of the all patients,79 cases of them were treated with CT,58 of them were treated with RT or CRT.The 5-year survival and prognosis factors were analyzed retrospectively,the prognosis was compared between two adjuvant therapy groups.Results The univariate analysis shown that types of pathology,different grade of risk factors,stroma invasion and lymph node involvement were prognostic factors of 5-year overall survival Patients with squamous cell carcinoma,intermediate risk factors,no parametrial invasion,and no lymph node involvement had better prognosis (P ＜ 0.05).Whether patients with high-risk factors or intermediate-risk factors,the 5-year overall survival and 3-year disease-free survival had no difference between CT and RCT or RT groups respectively.Cox regression multivariate analysis of survival indicated that clinical stages,types of histology,different grade of risk factors were independent prognostic indicator.Patients with early stage,squamous cell carcinoma,intermediate risk factors had better prognosis.Univariate and multivariate analysis indicated that different postoperative adjuvant therapies had no effects on the prognosis.The 5-year overall survival was 88.6％ in patients treated with CT,and 89.7％ in patients treated with RT or CRT (P =0.455).Conclusion There are equivalent therapeutic results between CT and RT or CRT for patients with risk factors after radical surgery,CT may be as one choice of postoperative adjuvant therapy for stage Ⅰ b-Ⅱ a cervical carcinoma with risk factors.