Development and validation of a nomogram to predict failure of 14-day negative nucleic acid conversion in adults with non-severe COVID-19 during the Omicron surge: a retrospective multicenter study

Background With the variability in emerging data,guidance on the isolation duration for patients with coronavirus disease 2019(COVID-19)due to the Omicron variant is controversial.This study aimed to determine the predictors of prolonged viral RNA shedding in patients with non-severe COVID-19 and construct a nomogram to predict patients at risk of 14-day PCR conversion failure.Methods Adult patients with non-severe COVID-19 were enrolled from three hospitals of eastern China in Spring 2022.Viral shedding time(VST)was defined as either the day of the first positive test or the day of symptom onset,whichever was earlier,to the date of the first of two consecutively negative PCR tests.Patients from one hospital(Cohort I,n=2033)were randomly grouped into training and internal validation sets.Predictors of 14-day PCR conversion failure were identified and a nomogram was developed by multivariable logistic regression using the training dataset.Two hospitals(Cohort II,n=1596)were used as an external validation set to measure the performance of this nomogram.Results Of the 2033 patients from Cohort I,the median VST was 13.0(interquartile range:10.0-16.0)days;716(35.2%)lasted>14 days.In the training set,increased age[per 10 years,odds ratio(OR)=1.29,95%confidence interval(CI):1.15-1.45,P<0.001]and high Charlson comorbidity index(OR=1.25,95%CI:1.08-1.46,P=0.004)were independent risk factors for VST>14 days,whereas full or boosted vaccination(OR=0.63,95%CI:0.42-0.95,P=0.028)and antiviral therapy(OR=0.56,95%CI:0.31-0.96,P=0.040)were protective factors.These predictors were used to develop a nomogram to predict VST>14 days,with an area under the ROC curve(AUC)of 0.73 in the training set(AUC,0.74 in internal validation set;0.76 in external validation set).Conclusions Older age,increasing comorbidities,incomplete vaccinations,and lack of antiviral therapy are risk factors for persistent infection with Omicron variant for>14 days.A nomogram based on these predictors could be used as a prediction tool to guide treatment and isolation strategies.

Laboratory-based Surveillance and Clinical Profile of Sporadic HEV Infection in Shanghai,China

The study aimed to describe the epidemiological,virological and clinical features of sporadic HEV infection in eastern China.A total of 6112 patient sera were tested for anti-HEV IgG or anti-HEV IgM during one consecutive year(between August 2018 and July 2019).HEV RNA presence was evaluated by RT-PCR and HEV sequences were phylogenetically analyzed.Clinical features of confirmed HEV-infected patients were delineated.The sero-positivity rate of anti-HEV IgG maintained stable around 40%,while an obvious winter spike of anti-HEV IgM prevalence was observed.A total of 111 patients were confirmed of HEV viremia by molecular diagnosis.Subtype 4d was predominant.Phylogenetic analyses suggest that certain strains circulate across species and around the country.Subjects with confirmed current HEV infection had a high median age(58 years)and males were predominant(62.2%).Most patients presented with jaundice(75.7%)and anorexia(68.0%).Significantly elevated levels of liver enzymes and bilirubin were observed.Remarkably,the baseline bilirubin level was positively correlated with illness severity.Pre-existing HBV carriage may deteriorate illness.The clinical burden caused by locally acquired HEV infection is increasing.Surveillance should be enforced especially during the transition period from winter to spring.Patients with higher level of bilirubin at disease onset had slower recovery from HEV infection.