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Background: Few studies have reported on the seroprevalence of antibodies against avian influenza A (H9N2) virus and the incidence of these infections in the northern China and among swine workers. Methods: We conducted a serological cohort study among people working with poultry or swine or the general population in Beijing, China. It comprised four cross‐sectional serological surveys in November 2013, April 2014, April 2015, and April 2016. Blood samples collected from the participants were tested for anti‐H9N2 antibodies using a hemagglutination‐inhibition (HI) assay. Multivariable Poisson regression model was then used to compare the person‐month incidence rates for H9N2 viral infections among the three groups, assessed by incidence rate ratio (IRR). Results: In the four cross‐sectional surveys, the highest seroprevalence of anti‐H9N2 antibodies (HI titer ≥ 80) was recorded in the poultry workers (2.77%, 19/685) in April 2016, while the lowest was recorded in the general population (0.09%, 1/1135) in April 2015. The highest incidence density rate for H9N2 infections across the whole study period was recorded among the poultry workers (3.75/1000 person‐months), followed by the swine workers (1.94/1000 person‐months) and the general population (1.78/1000 person‐months). Multivariable analysis showed that the poultry workers were at higher risk (IRR: 2.42, 95% CI: 1.07‐5.48; P = 0.034) of contracting H9N2 virus than the general population. Conclusions: Although the seroprevalence of H9N2 antibodies was low in Beijing, the poultry workers were at higher risk of contracting H9N2 viral infections than the general population. Closer monitoring and strengthened protection measures for poultry workers are warranted. [ABSTRACT FROM AUTHOR]

Background: Bacterial colonisation of the respiratory tract is commonly described and usually thought to be of no clinical significance. The aim of this study was to examine the presence and significance of bacteria and viruses in the upper respiratory tract of healthcare workers (HCWs), and association with respiratory symptoms.Methods: A prospective cohort study was conducted in China and 223 HCWs were recruited from fever clinics and respiratory, paediatric, emergency/Intensive medication wards. Participants were followed over 4 weeks (7th May 2015 to 4th June 2015) for development of clinical respiratory illness (CRI). Nasopharyngeal swabs were obtained at baseline and at the end of the study. The primary endpoints were laboratory-confirmed bacterial colonisation and viral respiratory infection. Rates of the following infections in symptomatic and asymptomatic participants were compared at the start or end of the study; 1) all bacterial/viral infections, 2) bacterial infection and bacterial-viral co-infections, excluding virus only infections, and 3) only bacterial infections.Results: Bacterial colonisation was identified in 88% (196/223) of participants at the start or end of the study. Among these participants, 66% (148/223) had only bacterial colonisation while 22% (48/223) had co-infection with a virus. Bacteria were isolated from 170 (76.2%) participants at baseline and 127 (57%) participants at the end of the study. Laboratory confirmed viral infections were identified in 53 (23.8%) participants - 35 (15.7%) at the baseline and 20 (9.0%) at the end of the study. CRI symptoms were recorded in 12 participants (4.5%) and all had a positive bacterium isolation at baseline (n = 11) or end of the study (n = 1). Among asymptomatic participants, 187 (87%) had bacterial colonisation or bacterial/viral co-infection at baseline or end of the study. Viruses were also isolated from 5 (2.4%) asymptomatic cases. Rates of all infection outcomes were higher in symptomatic participants, however differences were not statistically significant.Conclusion: We isolated high rates of bacteria and viruses in the upper respiratory tract of hospital HCWs, which may reflect greater exposure to respiratory infections in the hospital. Although respiratory infections are mostly symptomatic, the association between bacterial colonization and symptomatic illness is not clear. In the healthcare setting, HCWs may acquire and transmit infection to patients and other HCWs around them. Larger studies are required to explore ongoing occupational risk of respiratory infection in hospitals HCWs. [ABSTRACT FROM AUTHOR]

Background: Burden of Group A streptococcus (GAS) pharyngitis is scarce in developing countries, still unknown in China. The objective of this study was to determine the incidence of clinical cases of pharyngitis and GAS culture-positive pharyngitis, and their outpatient visits among children aged 0-14 years in Beijing, the capital of China.Methods: Multiplier model was used to estimate the numbers of pharyngitis cases, based on reported numbers of clinical cases and GAS culture-positive rates from GAS surveillances in Beijing, consultation rate, population coverage of GAS surveillances, sampling success rate, and test sensitivity of GAS culture from previous studies, surveys and surveillances.Results: An average of 29804.6 (95 % CI: 28333.2-31276.0) clinical cases of pharyngitis per 100,000 person-years occurred among children aged 0-14 years, resulting in correspondingly 19519.0 (95 % CI: 18516.7-20521.2) outpatient visits per 100,000 person-years from 2012 to 2014 in Beijing. On average, there were 2685.1 (95 % CI: 2039.6-3330.6) GAS culture-positive cases of pharyngitis and 1652.7 (95 % CI: 1256.5-2049.0) outpatient visits per 100,000 person-years during the same period. The estimated burden of GAS pharyngitis was significantly higher than that of scarlet fever. Children aged 5-14 years had a higher burden of GAS pharyngitis than those aged 0-4 years.Conclusions: The present data suggests that GAS pharyngitis is very common in children in China. Further studies and surveillances are needed to monitor trends and the effectiveness of control measures. [ABSTRACT FROM AUTHOR]

Please cite this paper as: Yang et al. (2011) Seroprevalence of pandemic (H1N1) 2009 influenza and effectiveness of 2010/2011 influenza vaccine during 2010/2011 season in Beijing, China. Influenza and Other Respiratory Viruses 6(6), 381-388. Background In the post-pandemic period, pandemic (H1N1) 2009 virus was expected to circulate seasonally and was introduced into trivalent influenza vaccine during 2010/2011 season in the Northern Hemisphere. Objectives The aim of this study was to examine the evolution of herd immunity against pandemic (H1N1) 2009 virus in Beijing, China, during 2010/2011 season and effectiveness of the 2010/2011 trivalent vaccine. Methods Two serological surveys were conducted before and after 2010/2011 season in Beijing. A case-control study was used to investigate vaccine effectiveness against influenza-like illness (ILI) and lower respiratory tract infection (LRI). Results A total of 4509 and 4543 subjects participated in the pre- and post-season surveys, respectively. The standardized seroprevalence of pandemic (H1N1) 2009 influenza increased from 22·1% pre-season to 24·3% post-season ( P < 0·001). Significant elevation in seroprevalence appeared in the ≥60 years age-group ( P < 0·001), but not in others. The 2010/2011 trivalent vaccine contributed to the higher post-seasonal seroprevalence in unvaccinated individuals ( P = 0·024), but not in those vaccinated with monovalent pandemic vaccine ( P = 0·205), as well as in those without prior immunity versus those with immunity. The adjusted effectiveness of the 2010/2011 trivalent vaccine was 79% protection against ILI (95% CI, 61-89%) and 95% against LRI (95% CI: 59-99%). Conclusions A slight increase in herd immunity against pandemic (H1N1) 2009 influenza was observed in Beijing, China, during the 2010/2011 season. Prior vaccination and immunity had a suppressive impact on immune response toward this novel influenza virus, elicited by 2010/2011 trivalent vaccine. This trivalent vaccine conferred good protection against ILI and LRI. [ABSTRACT FROM AUTHOR]

Background: Medical masks are commonly used in health care settings to protect healthcare workers (HCWs) from respiratory and other infections. Airborne respiratory pathogens may settle on the surface of used masks layers, resulting in contamination. The main aim of this study was to study the presence of viruses on the surface of medical masks.Methods: Two pilot studies in laboratory and clinical settings were carried out to determine the areas of masks likely to contain maximum viral particles. A laboratory study using a mannequin and fluorescent spray showed maximum particles concentrated on upper right, middle and left sections of the medical masks. These findings were confirmed through a small clinical study. The main study was then conducted in high-risk wards of three selected hospitals in Beijing China. Participants (n = 148) were asked to wear medical masks for a shift (6-8 h) or as long as they could tolerate. Used samples of medical masks were tested for presence of respiratory viruses in upper sections of the medical masks, in line with the pilot studies.Results: Overall virus positivity rate was 10.1% (15/148). Commonly isolated viruses from masks samples were adenovirus (n = 7), bocavirus (n = 2), respiratory syncytial virus (n = 2) and influenza virus (n = 2). Virus positivity was significantly higher in masks samples worn for > 6 h (14.1%, 14/99 versus 1.2%, 1/49, OR 7.9, 95% CI 1.01-61.99) and in samples used by participants who examined > 25 patients per day (16.9%, 12/71 versus 3.9%, 3/77, OR 5.02, 95% CI 1.35-18.60). Most of the participants (83.8%, 124/148) reported at least one problem associated with mask use. Commonly reported problems were pressure on face (16.9%, 25/148), breathing difficulty (12.2%, 18/148), discomfort (9.5% 14/148), trouble communicating with the patient (7.4%, 11/148) and headache (6.1%, 9/148).Conclusion: Respiratory pathogens on the outer surface of the used medical masks may result in self-contamination. The risk is higher with longer duration of mask use (> 6 h) and with higher rates of clinical contact. Protocols on duration of mask use should specify a maximum time of continuous use, and should consider guidance in high contact settings. Viruses were isolated from the upper sections of around 10% samples, but other sections of masks may also be contaminated. HCWs should be aware of these risks in order to protect themselves and people around them. [ABSTRACT FROM AUTHOR]

As the pandemic (H1N1) 2009 progressed, the Ministry of Health of China advised cases with mild symptoms to remain home for isolation and observation, which may have increased the risk for infection among other household members. Describing the transmission characteristics of this novel virus is indispensable to effectively controlling the spread of disease; thus, the aim of this study was to assess risk factors associated with household transmission of pandemic H1N1 from self-quarantined patients in Beijing, the capital city of China. A 1:2 case-control study with 54 case households and 108 control households was conducted between August 1 and September 30, 2009 in Beijing. Cases were households with a self-quarantined index patient and a secondary case, while controls were households with a self-quarantined index patient and a close contact. Controls were also matched to cases for sex and age of index case-patient. A structured interview guide was used to collect the data. Conditional logistical models were employed to estimate Odds Ratios (OR) with 95% confidence intervals (95% CI). Results indicated that higher education level (OR 0.42; 95% CI 0.22-0.83), sharing room with an index case-patient (OR 3.29; 95%CI 1.23-8.78), daily room ventilation (OR 0.28; 95%CI 0.08-0.93), and hand washing ≥3/d (OR 0.71; 95%CI 0.48-0.94) were related to the household transmission of pandemic H1N1 from self-quarantined patients. These results highlight that health education, as well as the quarantine of the index case-patient immediately after infection, frequent hand hygiene, and ventilation are critical to mitigating household spread of pandemic H1N1 virus and minimizing its impact. Household contacts should be educated to promote these in-home practices to contain transmission, particularly when household members are quarantined at home. [ABSTRACT FROM AUTHOR]

Due to the national dynamic zero-COVID strategy in China, there were no persistent local transmissions of SARS-CoV-2 in Beijing before December, 2022. However, imported cases have been frequently detected over the past 3 years. With soaring growth in the number of COVID-19 cases in China recently, there are concerns that there might be an emergence of novel SARS-CoV-2 variants. Routine surveillance of viral genomes has been carried out in Beijing over the last 3 years. Spatiotemporal analyses of recent viral genome sequences compared with that of global pooled and local data are crucial for the global response to the ongoing COVID-19 pandemic. We routinely collected respiratory samples covering both imported and local cases in Beijing for the last 3 years (of which the present study pertains to samples collected between January and December, 2022), and then randomly selected samples for analysis. Next-generation sequencing was used to generate the SARS-CoV-2 genomes. Phylogenetic and population dynamic analyses were performed using high-quality complete sequences in this study. We obtained a total of 2994 complete SARS-CoV-2 genome sequences in this study, among which 2881 were high quality and were used for further analysis. From Nov 14 to Dec 20, we sequenced 413 new samples, including 350 local cases and 63 imported cases. All of these genomes belong to the existing 123 Pango lineages, showing there are no persistently dominant variants or novel lineages. Nevertheless, BA.5.2 and BF.7 are currently dominant in Beijing, accounting for 90% of local cases since Nov 14 (315 of 350 local cases sequenced in this study). The effective population size for both BA.5.2 and BF.7 in Beijing increased after Nov 14, 2022. The co-circulation of BF.7 and BA.5.2 has been present in the current outbreak since Nov 14, 2022 in Beijing, and there is no evidence that novel variants emerged. Although our data were only from Beijing, the results could be considered a snapshot of China, due to the frequent population exchange and the presence of circulating strains with high transmissibility. National Key Research and Development Program of China and Strategic Priority Research Program of the Chinese Academy of Sciences. For the Chinese translation of the abstract see Supplementary Materials section. [ABSTRACT FROM AUTHOR]

We analyzed the prevalence and genotypes of Parechovirus A (PeV-A) in children with diarrhea in Beijing, China, 2017–2019. A total of 1734 stool samples collected from children <5 years of age with diarrhea were tested for the presence of PeV-A. Viral RNA was detected by real-time RT-PCR, and then genotyped by nested RT-PCR. We detected PeV-A in 93 (5.4%, 93/1734) samples, of which 87 could be genotyped by amplification of either the complete or partial VP1 region or the VP3/VP1 junction region. The median age of PeV-A infected children was 10 months. Most PeV-A infections were observed between August and November, with a peak in September. Seven known genotypes of PeV-A1A, -A1B, −A3, −A4, −A6, −A8 and -A11 were detected and PeV-A1B was the most prevalent genotype. Coinfection with other diarrheal viruses was observed in 30.1% (28/93) of PeV-A positive samples. All strains of PeV-A1A, -A1B, −A4 and -A6 obtained in this study contained the arginine-glycine-aspartic acid (RGD) motif, while all strains of PeV-A3, −A8 and -A11 lacked it. This study revealed a high genetic diversity of PeV-A circulating in Beijing and PeV-A11 was reported for the first time in children with diarrhea in China. • A total of 1734 stool samples were detected, and 93 samples (5.4%) were positive for PeV-A. • Based on VP1 genes and VP3/VP1 junction region genes, 79 and 72 strains were genotyped successfully, respectively. • Seven known genotypes of PeV-A1A, -A1B, −A3, −A4, −A6, −A8 and -A11 were detected. • PeV-A11 was reported for the first time in children with diarrhea in China. [ABSTRACT FROM AUTHOR]

The first locally acquired case in the Chinese mainland was reported on May 31, 2023, lagging behind other countries. In this study, we aimed to examine the early clinical and epidemiological characteristics of the earliest cases of Mpox in Beijing, China. Additionally, we investigated the sequence and transmission patterns of the Mpox virus (MPXV). We analyzed 37 reported cases of Mpox in Beijing from May 31, 2023 to June 21, 2023. The age range of the subjects was 24-51 years. Thirty-six cases (97.3%) were identified in men who have sex with men (MSM), and 19 cases (51.4%) tested positive for the human immunodeficiency virus. Thirty-three cases were symptomatic, while four were asymptomatic. Skin lesions were observed in 32 cases (97.0%), fever in 26 (78.8%), and swollen lymph nodes in 17 (51.5%). Rash typically appeared in the genital or perianal area 1-3 days before fever onset, with a minimum incubation period of 2 days. For individuals with skin rashes, the skin lesion samples showed 100% positivity and low Ct values. There were high oropharyngeal swab (75.8%) and blood (84.6%) positivity rates. All MPXV strains belonged to the B.1.3 branch of the West African lineage. These strains carried 76-86 nucleotide substitutions compared with the reference human MPXV genome, and genetic diversity was observed. Our findings provide the first insights into the landscape of early transmission of Mpox in Beijing and help inform policy formulation in the Chinese mainland.

Norovirus (NoV) is the leading pathogen responsible for global acute gastroenteritis (AGE) outbreaks and sporadic cases. NoV evolves through gene mutation and recombination, leading to the emergence of new strains capable of causing global epidemics. This study aimed to learn the epidemiological characteristics of 39 GI.6[P11] NoV outbreaks in Beijing, China, from 2016 to 2019 and to analyze the genetic diversity and phylogenetic process of GI.6[P11] strains. The Bayesian phylogenetic analysis of partial VP1 and RNA-dependent RNA polymerase (RdRp) genes showed that GI.6[P11] strains were clustered into four subclades. Eleven whole genome sequences were obtained through the amplicon sequencing with 16 pairs of newly designed primers. The phylogenetic trees based on the whole genome and ORF1, 2, and 3 showed that the clustering of the 11 strains was consistent with that of partial VP1 and RdRp genes. The Bayesian inference revealed that the most recent ancestor (TMRCA) for the four subclades of the phylogenetic tree based on the whole genome sequences was 2012.42, 2014.81, 2011.74, and 2015.53, respectively. The recombination sites of GI.6[P11] strains in Beijing were located near the ORF1/2 junction. The histo-blood group antigens (HBGA) binding sites of GI.6[P11] strains in Beijing were conserved and there were some unique amino acid mutations in non-structural proteins in the ORF1 region., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

The transmissibility is a crucial feature for norovirus, yet its quantitative estimation has been limited. Our objective was to estimate the basic reproduction number (R 0 ) of norovirus and investigate its variation characteristics. Norovirus outbreaks reported from September 2016 to August 2021 in Beijing were analyzed. The susceptible-infected-removed compartment model was established to estimate R 0 . Linear regression models and logistic regression models were used to explore the factors affecting the transmissibility of norovirus. The overall median R 0 of norovirus was estimated as 2.1 (interquartile range [IQR] 1.8-2.5), with 650 norovirus outbreaks. The transmissibility of norovirus varied by year, outbreak setting and genotype. The R 0 of norovirus during September 2019 to August 2020 (median 2.1, IQR 1.8-2.4) and September 2020 to August 2021 (median 2.0, IQR 1.7-2.3) was lower than that of September 2016 to August 2017 (median 2.3, IQR 1.8-2.7) (β = 0.94, p = 0.05; β = 0.93, p = 0.008). The R 0 of norovirus for all other settings was lower than that for kindergarten (median 2.4, IQR 2.0-2.9) (primary school: median 2.0, IQR 1.7-2.4, β = 0.94, p = 0.001; secondary school: median 1.7, IQR 1.5-2.0, β = 0.87, p < 0.001; college: median 1.7, IQR 1.5-1.8, β = 0.89, p = 0.03; other closed settings: median 1.8, IQR 1.5-2.0, β = 0.90, p = 0.004). GⅡ.2[P16] outbreaks had a median R 0 of 2.2 (IQR 1.8-2.7), which was higher than that for GⅡ.6[P7] outbreaks (median 1.8, IQR: 1.8-2.0, odds ratio = 0.19, p = 0.03; GⅡ.2[P16] as reference) and mixed-genotype outbreaks (median 1.7, IQR: 1.5-1.8, β = 0.92, p = 0.02; mixed-genotype as reference). In kindergartens and primary schools, norovirus shows increased transmissibility, emphasizing the vulnerable population and high-risk settings. Furthermore, the transmissibility of norovirus may change over time and with virus evolution, necessitating additional research to uncover the underlying mechanisms., (© 2023 Wiley Periodicals LLC.)

Coxsackievirus A16 (CV-A16) is a significant pathogen responsible for causing hand foot and mouth disease (HFMD) and herpangina (HA). This study aimed to investigate the recent evolution and spread of CV-A16 by monitoring HFMD and HA cases in 29 hospitals across 16 districts in Beijing from 2019 to 2021. The first five cases of HFMD and the first five cases of HA each month in each hospital were included in the study. Real-time reverse transcription polymerase chain reaction was used to identify CV-A16, CV-A6, and EV-A71. From each district, two to four CV-A16 positive samples with a relatively long sampling time interval every month were selected for sequencing. A total of 3344 HFMD cases and 2704 HA cases were enrolled in this study, with 76.0% (2541/3344) of HFMD and 45.4% (1227/2704) of HA cases confirmed to be infected by enterovirus. Among the EV-positive samples, CV-A16 virus was detected in 33.61% (854/2541) of HFMD cases and 13.4% (165/1227) of HA cases, with the predominant cluster being B1a. Both B1a and B1b had a co-circulation of local and imported strains, with different origin time (1993 vs. 1995), different global distribution (14 countries vs. 10 countries), and different transmission centers but mainly distributed in the southern and eastern regions of Beijing. Strengthening surveillance of HFMD in southern and eastern regions will improve the prevention and control efficiency of enterovirus infections., (© 2023 Wiley Periodicals LLC.)

Background: Noroviruses are a leading cause of acute gastroenteritis (AGE) worldwide. The geographical characteristics of norovirus outbreaks in Beijing and their influencing factors remain unknown. This study aimed to explore the spatial distributions, geographical characteristics, and influencing factors of norovirus outbreaks in Beijing, China., Methods: Epidemiological data and specimens were collected through the AGE outbreak surveillance system in all 16 districts of Beijing. Data on spatial distribution, geographical characteristics, and influencing factors of norovirus outbreaks were analyzed using descriptive statistics methods. We measured spatial, geographical clustering of high- or low-value deviance from random distribution using Z-scores and P-values as statistical significance measures with Global Moran's I statistics and Getis-Ord Gi in ArcGIS. Linear regression and correlation methods were used to explore influencing factors., Results: Between September 2016 and August 2020, 1,193 norovirus outbreaks were laboratory-confirmed. The number of outbreaks varied seasonally, typically peaking in spring (March to May) or winter (October to December). Outbreaks primarily occurred around central districts at the town level, and spatial autocorrelation was evident in both the entire study period and in individual years. Hotspots of norovirus outbreaks in Beijing were primarily found in contiguous areas between three central districts (Chaoyang, Haidian, Fengtai) and four suburban districts (Changping, Daxing, Fangshan, Tongzhou). The average population numbers, mean number of all schools, and mean number of kindergartens and primary schools for towns in central districts and hotspot areas were higher than those in suburban districts and non-hotspot areas respectively. Additionally, population numbers and densities of kindergartens and primary schools were influencing factors at the town level., Conclusions: Hotspots of norovirus outbreaks in Beijing were in contiguous areas between central and suburban districts with high populations, and high kindergarten and primary school densities were the likely driving forces. Outbreak surveillance needs to focus on contiguous areas between central and suburban districts with increased monitoring, medical resources, and health education., (© 2023. The Author(s).)

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne disease with an increasing annual incidence rate. In this case report, we presented two patients infected with the SFTS virus, suggesting a potential direct transmission route from camels to humans through blood contact. Both patients developed symptoms after engaging in the slaughtering of one sick camel, while their family members living in the same environment or co-diners remained unaffected. Subsequent detection revealed a high viral load of SFTS virus, reaching 10 10 viral RNA copies/ml, in the sample obtained from the sick camel. Metagenomic sequencing did not identify any other pathogens. The SFTS virus was successfully isolated from both patient and camel samples. The complete nucleotide sequences obtained from the infected patients demonstrated a remarkable 100% similarity to those found in the camel, and genetic evolution analysis classified the virus as genotype A. Additionally, partial sequences of the SFTS virus were identified in ticks captured from the camel rearing environment, however, these sequences showed only 95.9% similarity to those found in camel and humans. Furthermore, immunoglobulin M and immunoglobulin G antibodies were detected in serum samples collected from the patient. Our findings provide evidence that camel may serve as a competent reservoir for transmitting the SFTS virus to humans. Further in vitro investigations into SFTS virus infections in large animals are warranted to understand their role in viral maintenance and transmission.

With COVID-19 public health control measures downgraded in China in January 2023, reported COVID-19 case numbers may underestimate the true numbers after the SARS-CoV-2 Omicron wave. Using a multiplier model based on our influenza surveillance system, we estimated that the overall incidence of SARS-CoV-2 infections was 392/100,000 population in Beijing during the 5 weeks following policy adjustment. No notable change occurred after the Spring Festival in early February. The multiplier model provides an opportunity for assessing the actual COVID-19 situation.

We compared the sensitivity and specificity of four commercial coronavirus disease (COVID-19) diagnostic kits using real-time reverse transcription-polymerase chain reaction (RT-PCR). Kits I-IV approved by the State Drug Administration of China were selected, and the detection targets were ORF1ab gene and N gene. Specificity was evaluated by detecting other respiratory viruses. The sensitivity and batch effect of each kit were evaluated by testing 10-fold dilutions of RNA. Clinical application was verified by testing nasopharyngeal swab and sputum specimens from COVID-19 patients. Among the 78 cases infected by other respiratory viruses, no amplification curve was observed using these four COVID-19 RT-PCR kits. The minimum detection limits of kits I-IV were 10 -6 , 10 -5 , 10 -5 , and 10 -6 dilutions, respectively, and concentrations were 10 copies/mL (10 -5 dilution) and 1 copies/mL (10 -6 dilution). The sensitivities of kits I-IV detected using 142 nasopharyngeal swab specimens from COVID-19 patients were 91.55%, 81.69%, 80.28%, and 90.85%, respectively, while they were 92.68%, 85.37%, 82.93%, and 93.90%, respectively, for the 82 sputum samples. The specificity of each kit was 100.00% (77/77). The total expected detection rate using sputum samples was 88.59% (691/780) higher than 86.15% (672/780) of nasopharyngeal swabs. Comparison of nasopharyngeal swab and sputum samples from the same COVID-19 patient led to the detection of ORF1ab and N genes in 16 (100%) sputum samples; only ORF1ab and N genes were detected in 12 (75%) and 14 (87.5%) nasopharyngeal swab specimens, respectively. In conclusion, comparison of commercial COVID-19 RT-PCR kits should be performed before using a new batch of such kits in routine diagnostics., (© 2020 The Authors. Journal of Clinical Laboratory Analysis Published by Wiley Periodicals LLC.)

Abstract: Since December 2019, an outbreak of COVID-19 sweeping the world. Understanding the clinical and SARS-CoV-2 dynamic changes of mild and ordinary patients of COVID-19, so as to provide basis for the prevention and control of COVID-19.On February 1st, 2020, 16 SARS-CoV-2 RNA positive patients diagnosed in the same site in Beijing. The patients symptoms, signs, medication, and SARS-CoV-2 results were recorded.Of the 16 patients, 12 were female. Although they were infected at the same time in the same workplace, their clinical processes were very different and can be roughly divided into three different types: persistent sputum positive, persistent stool positive and persistent both positive. In 7 patients with mild clinical manifestations, the median days of SARS-CoV-2 RNA negative conversion in sputum samples were significantly later than those with obvious lung injury (27 days [range: 18 to 36]; 17 days, [range 6 to 25], P = .021). The negative conversion of SARS-CoV-2 RNA in stool was significant later than in sputum.There were various clinical manifestations after SARS-CoV-2 infection, even if they were infected by the same source of infection in the same place. The presence of SARS-CoV-2 virus RNA in stool samples was longer than that in respiratory tract., (Copyright © 2020 the Author(s). Published by Wolters Kluwer Health, Inc.)

Background: Children aged under 5 years are particularly vulnerable to influenza infection. In this study, we aim to estimate the number and incidence of influenza among young children and estimate the impact of childhood vaccination in different scenarios from 2013/14 to 2016/17 seasons., Methods: The number and incidence rate of influenza infections among children aged under 5 years in Beijing was estimated by scaling up observed surveillance data. Then, we used a susceptible-exposed-infected-recovery (SEIR) model to reproduce the weekly number of influenza infections estimated in Beijing during the study seasons, and to estimate the number and proportion of influenza-attributed medically attended acute respiratory infections (I-MAARI) averted by vaccination in each season. Finally, we evaluated the impact of alternative childhood vaccination programs with different coverage and speed of vaccine distribution., Results: The estimated average annual incidence of influenza in children aged under 5 years was 33.9% (95% confidence interval (CI): 27.5%, 47.2%) during the study period. With the actual coverage during the included seasons at around 2.9%, an average of 3.9% (95%CI: 3.5%, 4.4%) I-MAARI was reduced compared to a no-vaccination scenario. Reaching 20%, 40%, 50%, 60%, 80% and 100% vaccine coverage would lead to an overall I-MAARI reduction of 25.3%, 42.7%, 51.9%, 57.0%, 65.3% and 71.2%. At 20% coverage scenario, an average of 28.8% I-MAARI will be prevented if intensive vaccination implemented in 2 months since the vaccine released., Conclusion: In Beijing, the introduction of a program for vaccinating young children, even at relatively low vaccine coverage rates, would considerably reduce I-MAARI, particularly if the vaccines can be quickly delivered.

Rationale: Medical masks are commonly used by sick individuals with influenza-like illness (ILI) to prevent spread of infections to others, but clinical efficacy data are absent., Objective: Determine whether medical mask use by sick individuals with ILI protects well contacts from related respiratory infections., Setting: 6 major hospitals in 2 districts of Beijing, China., Design: Cluster randomised controlled trial., Participants: 245 index cases with ILI., Intervention: Index cases with ILI were randomly allocated to medical mask (n=123) and control arms (n=122). Since 43 index cases in the control arm also used a mask during the study period, an as-treated post hoc analysis was performed by comparing outcomes among household members of index cases who used a mask (mask group) with household members of index cases who did not use a mask (no-mask group)., Main Outcome Measure: Primary outcomes measured in household members were clinical respiratory illness, ILI and laboratory-confirmed viral respiratory infection., Results: In an intention-to-treat analysis, rates of clinical respiratory illness (relative risk (RR) 0.61, 95% CI 0.18 to 2.13), ILI (RR 0.32, 95% CI 0.03 to 3.13) and laboratory-confirmed viral infections (RR 0.97, 95% CI 0.06 to 15.54) were consistently lower in the mask arm compared with control, although not statistically significant. A post hoc comparison between the mask versus no-mask groups showed a protective effect against clinical respiratory illness, but not against ILI and laboratory-confirmed viral respiratory infections., Conclusions: The study indicates a potential benefit of medical masks for source control, but is limited by small sample size and low secondary attack rates. Larger trials are needed to confirm efficacy of medical masks as source control., Trial Registration Number: ACTRN12613000852752; Results., Competing Interests: All authors have completed the Unified Competing Interests form (available on request from the corresponding author) and declare that: CRM has held an Australian Research Council Linkage Grant with 3M as the industry partner, for investigator driven research. 3M have also contributed supplies of masks and respirators for investigator-driven clinical trials. She has received research grants and laboratory testing as in-kind support from Pfizer, GSK and Bio-CSL for investigator-driven research. HS had an NHMRC Australian based Public Health Training Fellowship at the time of the study (1012631). She has also received funding from vaccine manufacturers GSK, bio-CSL and Saniofi Pasteur for investigator-driven research and presentations. AAC had testing of filtration of masks by 3M for PhD., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

This study described some essential viral and sera-characteristics of A/H7N9 virus infection in a 61-year old case patient. With the antiviral therapy and respiratory support, the patient showed a significant decrease of viral loads from 6.72 log10 copies/mL to 0 in 22 days, and a correlated increase of serum hemagglutination inhibition titers during the same period. Phylogenetic analysis demonstrated that the isolated strain was highly homologous to previous strains isolated in the southeast of China. Drug resistance-associated R292K mutation became detectable 17 days after antiviral therapy, but no remarkable influence on the viral clearance was observed.

Background: A(H1N1) 09pdm and A(H3N2) influenza viruses are the main cause of occasional influenza pandemics and seasonal influenza epidemics around the world. Unfortunately, the understanding of long-term genetic variation in these viruses remains limited., Methods: In this study, hemagglutinin genes from 90 A(H1N1) 09pdm and 48 A(H3N2) influenza viruses in the Beijing area from 2009 to 2014 were sequenced and analyzed., Results: The hemagglutinin genes in A(H1N1) 09pdm and A(H3N2) shared nucleotide similarity that ranged from 93.06% - 99.88% and 98.68% - 99.29%, respectively, compared with current vaccine strains. 10 and 7 amino acid mutations in antigenic sites were identified in these two strains, respectively. In addition, a new site 177 glycosylation, which did not exist in previous circulating strains, was identified in 3 A(H1N1) 09pdm isolates., Conclusions: This study demonstrated the continued evolution of seasonal influenza viruses in the Beijing area, indicating that an update of the vaccine is needed, especially for A(H1N1) 09pdm influenza virus.

Background: Influenza vaccine coverage remains low in China, and there is limited information on the preventive value of local vaccination programs., Methods: As part of influenza virological surveillance in Beijing, China during the 2012-2013 influenza season, we assessed the vaccine effectiveness (VE) of one or more doses of trivalent inactivated influenza vaccine (IIV3) in preventing medically-attended influenza-like-illness (ILI) associated with laboratory-confirmed influenza virus infection using a test-negative case-control design. Influenza vaccination was determined based on self-report by adult patients or the parents of child patients., Results: Of 1998 patients with ILI, 695 (35%) tested positive for influenza viruses, including 292 (42%) A(H3N2), 398 (57%) A(H1N1)pdm09, and 5 (1%) not (sub)typed influenza viruses. The rate of influenza vaccination among all patients was 4% (71/1998). Among influenza positive patients, 2% (57/1303) were vaccinated compared to 4% (14/695) among influenza negative patients, resulting in VE for one or more doses of vaccine (adjusted for age, sex, week, and days since illness onset) against all circulating influenza viruses of 52% (95% CI=12-74%). A significant adjusted VE for one or more doses of vaccine for all ages against A(H1N1)pdm09 of 59% (95% CI, 8-82%) was observed; however, the VE against A(H3N2) was 43% (95% CI, -30% to 75%). The point estimate of VE was 59% (95% CI, 19-79%) for those aged <60 years, but a negative VE point estimate without statistical significance was observed among those aged ≥60 years., Conclusions: IIV3 conferred moderate protection against medically-attended influenza in Beijing, China during the 2012-2013 season, especially against the A(H1N1)pdm09 strain and among those aged <60 years old., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Objective: To analyze the prevalence of super-antigens (SAgs) of group A streptococcus (GAS)isolated from Beijing pediatric patients in 2011, and to explore the relationship between emm types, characteristics of patients and SAgs., Methods: A total of 635 isolates of GAS were collected from children in 36 hospitals in Beijing from May to July, 2011. Thirteen currently known SAg genes were tested by real-time PCR, and emm gene was performed by PCR and sequencing of N-terminal gene fragments of M protein., Results: Prevalence rates of 13 SAg genes speA, speB, speC, speF, speG, speH, speI, speJ, speK, speL, speM, smeZ, ssa were 22.4%, 100.0%, 99.4%, 99.7%, 99.7%, 76.4%, 76.2%, 21.7%,0.6%, 1.1%, 2.2%, 99.7% and 98.0%, respectively. A total of 26 SAgs profiles were observed according to the SAgs inclusion. There were significant differences in frequencies of speA, speH, speI and speJ between emm1 and emm12 strains (P < 0.05). In isolates from patients with pharyngeal infection, the prevalence rates for speK and speL were higher while the frequency for ssa was lower than that from scarlet fever cases (P < 0.05)., Conclusion: The frequencies of speB, speF, smeZ, speG, speC, and ssa were high among strains isolated while speM, speL and speK were relatively low from children in Beijing, 2011. SAg genes appeared to be associated with the emm types. In this study, differences of frequency for speA and speC from strains collected from patients with scarlet fever and pharyngeal infection had not been found.

During surveillance for pneumonia of unknown etiology and sentinel hospital-based surveillance in Beijing, China, we detected avian influenza A(H7N9) virus infection in 4 persons who had pneumonia, influenza-like illness, or asymptomatic infections. Samples from poultry workers, associated poultry environments, and wild birds suggest that this virus might not be present in Beijing.

Scarlet fever is one of a variety of diseases caused by group A Streptococcus (GAS). During 2011, a scarlet fever epidemic characterized by peak monthly incidence rates 2.9-6.7 times higher than those in 2006-2010 occurred in Beijing, China. During the epidemic, hospital-based enhanced surveillance for scarlet fever and pharyngitis was conducted to determine characteristics of circulating GAS strains. The surveillance identified 3,359 clinical cases of scarlet fever or pharyngitis. GAS was isolated from 647 of the patients; 76.4% of the strains were type emm12, and 17.1% were emm1. Almost all isolates harbored superantigens speC and ssa. All isolates were susceptible to penicillin, and resistance rates were 96.1% to erythromycin, 93.7% to tetracycline, and 79.4% to clindamycin. Because emm12 type GAS is not the predominant type in other countries, wider surveillance for the possible spread of emm12 type GAS from China to other countries is warranted.

Active surveillance and diagnosis of the influenza pandemic (H1N1) 2009 (pH1N1) have played a critical role in the effective control and prevention of the pandemic in China. Although several commercially available real-time PCR kits for pH1N1 virus have been used in diagnostic laboratories in Beijing, little has been known about the performance of these kits for detecting pH1N1 virus. In this study, the performance of two commercial real-time PCR kits in Beijing was evaluated. Analysis of clinical samples showed that the positive detection rate for the AgPath-ID™ kit (38.2%) was significantly higher than that for the Da An H1N1 kit (30.0%) (McNemar's chi-square test, P=0.000). The limit of detection (LOD) of the AgPath-ID™ kit was 10(2), 10(2), and 10(3) copies/reaction for the Influenza A (set 1), H1N1 Influenza A (set 2) and H1N1 Influenza A Sub H1 (set 3) genes, respectively, whereas the LOD of the Da An kit was 10(3) copies/reaction for both H1 and N1 genes. Although the AgPath-ID™ kit exhibited a significantly higher detection rate for pH1N1 than the Da An kit, cross-reactivity to A/PR8/34 was found for the AgPath-ID™ kit for H1N1 Influenza A (set 2)., (Copyright © 2012 Elsevier B.V. All rights reserved.)

The continued spread of highly pathogenic avian influenza (HPAI) viruses of H5 and H7 subtypes and low pathogenic avian influenza (LPAI) viruses of H5, H7 and H9 subtypes in birds and the subsequent infections in humans pose an ongoing pandemic threat. It has been proposed that poultry workers are at higher risk of exposure to HPAI or LPAI viruses and subsequently infection due to their repeated exposure to chickens or domestic waterfowl. The aim of this study was to examine the seroprevalence of antibodies against H5, H7 and H9 viruses amongst duck-related workers in Beijing, China and the risk factors associated with seropositivity. In March, 2011, 1741 participants were recruited from (1) commercial duck-breeding farms; (2) private duck-breeding farms; and (3) duck-slaughtering farms. Local villagers who bred ducks in their backyards were also recruited. A survey was administered by face-to-face interview, and blood samples were collected from subjects for antibody testing against H5, H7 and H9 viruses. We found that none of the subjects were seropositive for either H5 or H7 viruses, and only 0.7% (12/1741) had antibody against H9. A statistically significant difference in H9 antibody seroprevalence existed between the various categories of workers (P = 0.005), with the highest figures recorded amongst the villagers (1.7%). Independent risk factors associated with seropositivity toinfection with H9 virus included less frequent disinfection of worksite (OR, 5.13 [95% CI, 1.07-24.58]; P = 0.041; ≤ twice monthly versus>twice monthly) and handling ducks with wounds on hands (OR, 4.13 [95% CI, 1.26-13.57]; P = 0.019). Whilst the risk of infection with H5, H7 and H9 viruses appears to be low among duck-related workers in Beijing, China, ongoing monitoring of infection with the H9 virus is still warranted, especially amongst villagers who breed backyard ducks to monitor for any changes.