Symptomatic and Asymptomatic SARS-CoV-2 Infection and Follow-up of Neutralizing Antibody Levels

Objective To investigate neutralizing antibody levels in symptomatic and asymptomatic patients with coronavirus disease 2019(COVID-19)at 6 and 10 months after disease onset.Methods Blood samples were collected at three different time points from 27 asymptomatic individuals and 69 symptomatic patients infected with severe acute respiratory syndrome coronavirus 2(SARS-Co V-2).Virus-neutralizing antibody titers against SARS-CoV-2 in both groups were measured and statistically analyzed.Results The symptomatic and asymptomatic groups had higher neutralizing antibodies at 3 months and 1–2 months post polymerase chain reaction confirmation,respectively.However,neutralizing antibodies in both groups dropped significantly to lower levels at 6 months post-PCR confirmation.Conclusion Continued monitoring of symptomatic and asymptomatic individuals with COVID-19 is key to controlling the infection.

Difference of Clinical Characteristics in Patients with Omicron and Delta Variants of SARS-CoV-2 in Beijing,China

Background Delta and Omicron are two main variants that have been prevalent since 2021.However,the Omicron variant of severe acute respiratory syndrome coronavirus 2 shows a less severe clinical presentation and high transmissibility.Therefore,we carried out this retrospective study to evaluate Omicron severity compared with the Delta variant and further comprehend the differences in clinical characteristics in patients with the Omicron variant.Methods We extracted clinical data and compared clinical severity,symptoms,vaccination status,laboratory parameters,viral shedding time,and computed tomography(CT)imaging between the two groups of patients,which included 109 COVID-19 cases with the Delta variant and 183 cases with the Omicron variant,from January 19 to April 1,2022,in Beijing Ditan Hospital.In addition,the Beijing Center for Disease Prevention and Control conducted whole-genome sequencing.Results We obtained 94 strains of variants of concern/Delta and 110 strains of variants of concern/Omicron.For the 110 Omicron strains,three were assigned as BA.1.1,53 as BA.2,and 54 as BA.2.2.Among patients with the Delta variant,54%(59/109)were moderate,which was significantly higher than that of patients with the Omicron variant(7%(12/183),P<0.001).The number of patients with mild symptoms in the Omicron group was significantly higher than in the Delta group(80%vs.35%,P<0.001).Compared with the Omicron group,patients with underlying diseases or obesity,60 years or older,or unvaccinated in the Delta group had more severe disease,and there was a significant difference between the two groups.The viral shedding time in the Omicron group was shorter than in the Delta group((11.9±5.9)vs.(14.0±5.8)days,P=0.003).Among the 183 patients in the Omicron group,104(57%)had dry or sore throat symptoms,more than those in the Delta group(34%(37/109);P<0.001).In the Delta group,patients in the moderate group had more fever and cough symptoms than those in the mild group.The remission time of CT imaging in the Omicron group was shorter than in the Delta group((9.0±5.2)vs.(13.2±4.2)days,P=0.018).Conclusions Patients with Delta variants are more likely to have pneumonia,mainly with fever and cough symptoms,while patients with the Omicron variant are mostly mild,with more prominent dry or sore throat symptoms.In addition,patients with the Omicron variant have a short viral shedding time and rapid absorption of pneumonia.

The first local case of mpox caused by an imported case in the Chinese mainland

Monkeypox (mpox) is a zoonotic disease caused by the mpox virus (MPXV) that has been primarily limited to Central and West African nations since its discovery. The recent spread of the West African lineage of MPXV in historically unaffected countries has raised concerns for global public health. Despite a significant decrease in global mpox cases, there is still a risk of a global resurgence. This study reports the first local case of mpox caused by an imported case in the Chinese mainland. Polymerase chain reaction (PCR) diagnosed the two cases, and the viral genomes were obtained by next-generation sequencing. Genomic analysis revealed that the two strains shared an identical genome sequence and belonged to the B.1.3 branch of the West African lineage, which is the first local case of mpox caused by an imported case in the Chinese mainland, highlighting the potential threat of mpox in China and the immediate need for adequate surveillance measures.

A Comparison of Clinical Characteristics of Infections with SARS-CoV-2 Omicron Subvariants BF.7.14 and BA.5.2.48-China,October-December 2022

Summary What is already known about this topic?Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)continues to evolve,the clinical manifestations resulting from different SARS-CoV-2 variants may demonstrate significant variation.What is added by this report?We conducted a comparative analysis of the clinical features associated with SARS-CoV-2 Omicron subvariants BF.7.14 and BA.5.2.48 infections.The results of our study indicate that there are no substantial differences in clinical manifestations,duration of illness,healthcare-seeking behaviors,or treatment between these two subvariants.What are the implications for public health practice?Timely identification of alterations in the clinical spectrum is crucial for researchers and healthcare practitioners in order to enhance their comprehension of clinical manifestations,as well as the progression of SARS-CoV-2.Furthermore,this information is beneficial for policymakers in the process of revising and implementing appropriate countermeasures.

The First Detection of Echinococcus Granulosus DNA in Residents’Hands,Dogs’Hair,and Soil in Highly Endemic Region of Echinococcosis-Naqu City,Xizang Autonomous Region,China,2020

Summary What is already known about this topic?Echinococcosis is a serious zoonotic parasitic disease that predominantly infects humans;domestic animals like cattle or sheep;as well as wild animals such as small rodents.To date,there is a lack of comprehensive information about all potential environmental transmission routes for Echinococcus.What is added by this report?This study assesses the importance of under-researched environmental factors for the transmission of Echinococcus.It concludes that hand hygiene is an important factor in the robust environmental transmission of Echinococcus granulosus.What are the implications for public health practice?This study suggests that residents are at risk of catching echinococcosis through hand-oral transmission routes.Health education given to local residents is thus a key intervention,as well as avoiding close contact with dogs and ensuring proper hand-washing practices are followed.

Superior effectiveness and acceptability of saliva samples for the detection of SARS-CoV-2 in China

In response to problems of poor sampling quality,low sensitivity,and high demand for medical personnel regarding the current severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)oropharyngeal(OP)swab sampling used in China,we aimed to evaluate the diagnostic performance and acceptability of saliva-based nucleic acid amplification tests(NAATs)in China.The results showed that,using nasopharyngeal(NP)swab results as the gold standard,the overall sensitivities for saliva specimens and OP swabs were 93.3%and 85.0%,the specificities were 92.6%and 93.8%,respectively.The results of an acceptability survey showed that the scores for saliva,OP,and NP samples were 9.46±1.69,8.11±2.42,and 4.58±3.82 out of 10,respectively,with significant differences among the three groups(P<o.05).With higher sensitivity,compa-rable specificity,and strong public preference,saliva-based NAATs represent a convenient and effective method for detecting SARS-CoV-2 in future epidemics.

Application of a ddRT-PCR to quantify seasonal influenza virus for viral isolation

Viral isolation in cell cultures has been regarded for decades as the“gold standard”for the laboratory diagnosis of influenza viral infections.Not all viral strains could be isolated from clinical samples.This study aimed to quantify the viral load in the samples before isolation to save working time and improve working efficiency.Four hundred samples from patients with influenza-like cases were confirmed pdmH1N1 positive(200 cases)and B Victoria(BV)positive(200 cases)by whole-genome sequencing and analyzed by ddPCR for viral load in samples before isolation,and isolation results were verified by hemagglutination(HA)assay and hemagglutination-inhibition(HI)tests.Probit regression analysis was used to calculate the isolation viral load limit with a 95%probability level by SPSS 19.0 software.The results showed that the isolation limit of viral load was 4.9×10^(4)(95%CI:2.5×10^(4)–9.0×10^(4))copies/mL for pdmH1N1 and 1.9×10^(4)(95%CI:7.8×103–3.6×10^(4))copies/mL for BV.The isolation rate of clinical samples is positively correlated with the viral load in clinical samples,which can be used for viral culture,providing important guidance for daily work.

Adaptively temporal graph convolution model for epidemic prediction of multiple age groups

Introduction:Multivariate time series prediction of infectious diseases is significant to public health,and the deep learning method has attracted increasing attention in this research field.Material and methods:An adaptively temporal graph convolution(ATGCN)model,which leams the contact patterns of multiple age groups in a graph-based approach,was proposed for COVID-19 and influenza prediction.We compared ATGCN with autoregressive models,deep sequence learning models,and experience-based ATGCN models in short-term and long-term prediction tasks.Results:Results showed that the ATGCN model performed better than the autoregressive models and the deep sequence learning models on two datasets in both short-term(12.5%and 10%improvements on RMSE)and longterm(12.4%and 5%improvements on RMSE)prediction tasks.And the RMSE of ATGCN predictions fluctuated least in different age groups of COVID-19(0.029±0.003)and influenza(0.059±0.008).Compared with the Ones-ATGCN model or the Pre-ATGCN model,the ATGCN model was more robust in performance,with RMSE of 0.0293 and 0.06 on two datasets when horizon is one.Discussion:Our research indicates a broad application prospect of deep learning in the field of infectious disease prediction.Transmission characteristics and domain knowledge of infectious diseases should be further applied to the design of deep learning models and feature selection.Conclusion:The ATGCN model addressed the multivariate time series forecasting in a graph-based deep learning approach and achieved robust prediction on the confirmed cases of multiple age groups,indicating its great potentials for exploring the implicit interactions of multivariate variables.

Genetic Features of 84 Genomes of Monkeypox Virus in Recent Circulation-Beijing Municipality,China,2023

The first indigenous incidence of Mpox(previously known as monkeypox)within Chinese mainland was documented in May 2023,with subsequent local and imported cases identified.A comprehensive understanding of the Mpox virus’s(MPXV)characteristics within Beijing remains incomplete.In this study,84 MPXV genomes from 82 local incidents and two imported instances,detected between May and July 2023,were analyzed.All MPXV strains fell within lineage C.1 of the West African clade,displaying limited genetic heterogeneity,encompassing 76–87 nucleotide substitutions and holding nucleotide identities between 99.996%and 100%.Phylogenetic exploration indicated that all genomes exhibited high homology to those presently prevalent in neighboring East Asian and Southeast Asian regions.Forty-six distinct haplotypes were identified among the strains,with 36.90%of genomes corresponding to four common haplotypes,suggesting repeated cross-regional introductions and restrained distribution via recurrent local transmission.These findings elucidate the genetic diversity and phylogenesis of MPXVs during their nascent transmission within Beijing and provide vital information to enhance future Mpox containment strategies.

The First Outbreak of Omicron Subvariant BA.5.2—Beijing Municipality,China,July 4,2022

On July 4,2022,the first case of Omicron subvariant BA.5.2 in Beijing Municipality was discovered in Yanqing District.The case was a 49-yearold Chinese male who had arrived in Shanghai Municipality via international flight DL9927 from North Carolina,U.S.on June 15.He stayed in a hotel for the 14-day arrival quarantine and was discharged on June 30.He arrived in Beijing via domestic flight MU5103 on July 1 and was transferred point-to-point from the airport to his residence community in Yanqing District.On July 3,his sample was collected through community mass screening and reported positive in the next morning.The case had received 3 doses of Moderna’s mRNA vaccines in the U.S.,with the last shot on May 26,2022.

Phylogenomic tracing of asymptomatic transmission in a COVID-19 outbreak

SARS-CoV-2 has caused over 100 million deaths and continues to spread rapidly around the world.Asymptomatic transmission of SARS-CoV-2 is the Achilles’heel of COVID-19 public health control measures.Phylogenomic data on SARS-CoV-2 could provide more direct information about asymptomatic transmission.In this study,using a novel MINERVA sequencing technology,we traced asymptomatic transmission of COVID-19 patients in Beijing,China.One hundred and seventy-eight close contacts were quarantined,and 14 COVID-19 patients were laboratory confirmed by RT-PCR.We provide direct phylogenomic evidence of asymptomatic transmission by constructing the median joining network in the cluster.These data could help us to determine whether the current symptom-based screening should cover asymptomatic persons.

Acute hepatitis of unknown aetiology among children around the world

By 26 August 2022, the number of cases of acute hepatitis of unknown etiology (AHUA) has drastically increased to 1115 distributed in 35 countries that fulfill the World Health Organization definition. Several hypotheses on the cause of AHUA have been proposed and are being investigated around the world. In the recent United Kingdom (UK) report, human adenovirus (HAdV) with adeno-associated virus (AAV) co-infection is the leading hypothesis. However, there is still limited evidence in establishing the causal relationship between AHUA and any potential aetiology. The leading aetiology continues to be HAdV infection. It is reported that HAdV genomics is not unusual among the population in the UK, especially among AUHA cases. Expanding the surveillance of HAdV and AAV in the population and the environment in the countries with AUHA cases is suggested to be the primary action. Metagenomics should be used in detecting other infectious pathogens on a larger scale, to supplement the detection of viruses in the blood, stool, and liver specimens from AUHA cases. It is useful to develop a consensus-specific case definition of AHUA to better understand the characteristics of these cases globally based on all the collected cases.