ABSTRACT
ObjectivesTo understand SARS-CoV-2 seroprevalence of convalescents and assess their the immunity. Furthermore, we intend to explore the association between antibody levels and with demographic factors. Methods177 COVID-19 convalescents in Sichuan Province were voluntarily participated in our study. 363 serum samples were collected from June, 2020 to November, 2020. Duration of seroprevelance in these convalescents and their demographic characteristics were described, and the risk factors to antibody levels were analysed. ResultsMen had more than twice the odds of having IgM antibody positive compared with women (OR=2.419, 95% CI:[1.232, 4.751]). Participants without symptoms were nearly 0.5 times IgG seropositive than those with symptoms (OR=0.455, 95% CI: [0.220, 0.940]). People aged[≥]60 years were nearly 3 times IgG seropositive than those who aged < 20 years (OR=2.986, 95% CI: [1.058, 8.432]). Seroprevalence in asymptomatic declined quicker than symptomatic. ConclusionsAge and gender may affect the antibody levels and seroprevalence. Asymptomatic appeared more easier to turn to seronegative than symptomatic.
ABSTRACT
An epidemiological investigation was carried out on a local cluster of outbreak caused by imported cases of Coronavirus Disease 2019 (COVID-19) in rural areas of Chengdu in December 2020, to find out the source of infection and the chain of transmission. According to
Subject(s)
Humans , COVID-19 , Disease Outbreaks , Epidemics , Quarantine , SARS-CoV-2ABSTRACT
We summarized the epidemiological investigation results of the first case of human infection with avian influenza A(H9N2) virus in Chengdu,China,in order to provide references for dealing with similar diseases scientifically in the future.The methods of field epidemiology and laboratory testing were used to collect the H9N2 case's clinical and epidemiological data,as well as collect and test the samples of the H9N2 case and the relevant environment,so that the possible sources of infection,the epidemiological characteristics and clinical features could be analyzed.Results showed that the H9N2 case contacted with poultry within 10 days before the onset of illness and the H9N2 virus nucleic acid was detected in the patient's specimen by PCR.This case suffered from several chronic diseases for a long time,although active treatments were taken this time,she died soon after onset.Her living environment,the chicken leftovers from cooking,and surrounding poultry markets were polluted by H9 avian influenza virus.Through the investigation,we could deduce that the infection source of this case was the chicken infecting H9N2 viruses from surrounding poultry markets.This would be the first fatality associated with influenza A (H9N2) virus infections in humans.And though avian influenza A(H9N2) virus was low pathogenic,infection could cause severe symptoms or death in people with severe underlying diseases.
