Epidemiological and Clinical Features of Patients with Scrub Typhus—Guangzhou City,Guangdong Province,China,2012–2018

Summary What is already known about this topic?Scrub typhus(ST)causes public health challenges in the“tsutsugamushi triangle”in the Asia-Pacific area greater than 13 million square kilometers,affecting an estimated one million people each year.What is added by this report?A retrospective study based on 4,501 hospitalized patients with ST in Guangzhou City,China,described the epidemiological and clinical characteristics,laboratory findings of ST.

Outbreaks of Acute Respiratory Disease Associated with Human Adenovirus Infection in Closed Camps,China,December 2011–March 2014

Summary What is already known on this topic?Human adenovirus(HAdV)was frequently associated with acute respiratory disease(ARD)outbreaks in military camps.What is added by this report?HAdV-B7,HAdV-B14,and HAdV-B55 were determined to be responsible for 3,2,and 4 ARD outbreaks in military camps,China,respectively,with a total attack rate of 28.0%during 2011 to 2014.

ARTICLE OPEN Viral dynamics and antibody responses in people with asymptomatic SARS-CoV-2 infection

Over 40% of the coronavirus disease 2019(COVID-19)COVID-19 patients were asymptomatically infected with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)and the immune responses of these asymptomatic individuals is a critical factor for developing the strategy to contain the COVID-19 pandemic.Here,we determined the viral dynamics and antibody responses among 143 asymptomatic individuals identified in a massive screening of more than 5 million people in eight districts of Wuhan in May 2020.Asymptomatic individuals were admitted to the government-designated centralized sites in accordance with policy.The incidence rate of asymptomatic infection is〜2.92/100,000.These individuals had low viral copy numbers(peaked at 315 copies/mL)and short-lived antibody responses with the estimated diminish time of 69 days.The antibody responses in individuals with persistent SARS-CoV-2 infection is much longer with the estimated diminish time of 257 days.These results imply that the immune responses in the asymptomatic individuals are not potent enough for preventing SARS-CoV-2 re-infection,which has recently been reported in recovered COVID-19 patients.This casts doubt on the efficacy of forming"herd-immunity"through natural SARS-CoV-2 infection and urges for the development of safe and effective vaccines.

Antibody-dependent cellular cytotoxicity response to SARS-CoV-2 in COVID-19 patients

Antibody-dependent cellular cytotoxicity(ADCC)responses to viral infection are a form of antibody regulated immune responses mediated through the Fc fragment.Whether severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)triggered ADCC responses contributes to COVID-19 disease development is currently not well understood.To understand the potential correlation between ADCC responses and COVID-19 disease development,we analyzed the ADCC activity and neutralizing antibody response in 255 individuals ranging from asymptomatic to fatal infections over 1 year post disease.ADCC was elicited by 10 days post-infection,peaked by 11-20 days,and remained detectable until 400 days post-infection.In general,patients with severe disease had higher ADCC activities.Notably,patients who had severe disease and recovered had higher ADCC activities than patients who had severe disease and deceased.Importantly,ADCC activities were mediated by a diversity of epitopes in SARS-COV-2-infected mice and induced to comparable levels against SARS-CoV-2 variants of concern(VOCs)(B.1.1.7,B.1.351,and P.1)as that against the D614G mutant in human patients and vaccinated mice.Our study indicates anti-SARS-CoV-2 ADCC as a major trait of COVID-19 patients with various conditions,which can be applied to estimate the extra-neutralization level against COVID-19,especially lethal COVID-19.