Objective:To examine the near-complete genomic analysis of norovirus (NoV) subtype GⅡ.17 [P17] outbreaks in Beijing Chaoyang District from 2014 to 2024.Methods:Data and specimens related to outbreaks of the NoV aggregation in Beijing′s Chaoyang District from 2014 to 2024 were collected. The NoV was identified using real-time fluorescence reverse transcription polymerase chain reaction (RT-PCR). Specimens with positive nucleic acid were amplified by standard PCR, whole genome sequencing and evolutionary analysis. Amino acid site variations were compared.Results:In Chaoyang District, from 2014 to 2024, a total of 637 aggregated outbreaks caused by the NoV infection were reported, of which 584 were successfully typed. The epidemic caused by the GⅡ.17 [P17] subtype accounted for 8.79% (56/637), which was the dominant epidemic gene subtype in 2014-2015, sporadic in 2016-2019, reappeared in 2022, and significantly increased in 2024 (27.27%, 24/88). Outbreaks caused by the GⅡ.17 [P17] subtype occurred mainly from October to December, with the main sites of occurrence in primary schools and kindergartens. This study yielded 53 near-complete genome sequences of the GⅡ.17 [P17] subtype from 46 incidents in Chaoyang District. The GⅡ.17 [P17] subtype sequences of Chaoyang District from 2014 to 2024 were segmented into three subgroups on the evolutionary tree, with sequences from 2014 to 2019, 2022 to April 2024, and May to December 2024 clustered into the d, e, and b subgroups, respectively. In the VP1 region′s P2 area, particularly at the HBGA binding site, subgroups b and e exhibited mutations in 22 and two sites, while subgroups b and e showed mutations in four and one sites, predominantly in the RdRp region.Conclusion:The outbreak caused by the NoV GⅡ.17 [P17] subtype in Chaoyang District from 2014 to 2024 continues, with a significant increase in 2024, and it becomes the dominant gene subtype from October to December. The sequence formation of the NoV GⅡ.17 [P17] subtype in Chaoyang District from January to April 2022 and from May to December 2024 shows two different evolutions, with specific mutation sites, requiring continuous monitoring of the NoV GⅡ.17 [P17] subtype.

Objective:To establish a fluorescent quantitative RT-PCR assay based on N_sgRNA of SARS-CoV-2 and preliminarily apply it on real samples.Methods:Recombinant plasmid, specific primers and probes of N_sgRNA were designed and synthesized based on Wuhan-Hu-1/2019_MN908947 and synthesis mechanism of subgenomic RNA (sgRNA). Using recombinant plasmid as amplification templates, the optimal reaction conditions and reaction system were screened according to the Ct value, fluorescence intensity, and shape of amplification curve and was evaluated for sensitivity, reproducibility, and specificity. Meanwhile, the possibility of practical application of the method was explored by testing 172 clinical samples and 256 municipal wastewater samples. Results:A qRT-PCR assay for N_sgRNA in SARS-CoV-2 was initially established. The detection limit of the assay was 20 copies/mL, and the variation coefficients of in-batch (0.002%~0.767%) and batch to batch repetition (0.016%~0.752%) were less than 1%. Only N_sgRNA recombinant plasmid was detected in the specificity assay. So the method is more highly sensitive, specific and reproducible. The RatiosgRNA/ gRNA of clinical samples HK.3, EG.5.1, JN.1 and their sub-lineages and their corresponding urban sewage samples in epidemic period were significantly different ( P<0.05). There is a strong correlation between the median of RatiosgRNA/ gRNA in clinical samples and sewage samples in the same period (correlation coefficient r=1.000, P=0.010). Conclusions:In this study, a qRT-PCR method for detecting N_sgRNA of SARS-CoV-2 was established and the method has the characteristics of higher sensitivity, stronger specificity and better repeatability, and it can be used to detect SARS-CoV-2 infectivity.

Objective:The SARS-CoV-2 has a high natural mutation rate, and dynamic monitoring of virus variants remains a key focus in current COVID-19 prevention and control efforts.Methods:In this study, a sensitive and rapid method for detecting SARS-CoV-2 omicron variant nucleic acid was established based on the BMD-PCR technology.Results:This method showed good specificity, and had no cross-reactivity with 11 common viruses transmitted via the respiratory and gastrointestinal tracts, and the limit of detection is 555 copies/ml. Compared with SARS-CoV-2 whole-genome sequencing result, among 50 samples with original Ct values ≤32 tested for the Omicron variant, 49 samples tested positive for the N679K mutation site using BMD-PCR Omicron variant detection, achieving a concordance rate of 98.00%. For 30 samples JN.1 lineage, 29 samples tested positive for the K356T mutation site using BMD-PCR JN.1 lineage detection, with a concordance rate of 96.67%. For 10 samples with original SARS-CoV-2 detection Ct values between 35 and 32, 7 samples tested positive for the N679K mutation site using BMD-PCR Omicron variant detection, Resultsing in a detection rate of 70.00%. For samples with SARS-CoV-2 nucleic acid detection Ct values>35, the detection rate for the N679K mutation site in the BMD-PCR Omicron variant was 20.00%.Conclusions:This method can serve as a high-throughput supplementary approach for the preliminary identification of SARS-CoV-2 variant genotypes.

Objective:To examine the near-complete genomic analysis of norovirus (NoV) subtype GⅡ.17 [P17] outbreaks in Beijing Chaoyang District from 2014 to 2024.Methods:Data and specimens related to outbreaks of the NoV aggregation in Beijing′s Chaoyang District from 2014 to 2024 were collected. The NoV was identified using real-time fluorescence reverse transcription polymerase chain reaction (RT-PCR). Specimens with positive nucleic acid were amplified by standard PCR, whole genome sequencing and evolutionary analysis. Amino acid site variations were compared.Results:In Chaoyang District, from 2014 to 2024, a total of 637 aggregated outbreaks caused by the NoV infection were reported, of which 584 were successfully typed. The epidemic caused by the GⅡ.17 [P17] subtype accounted for 8.79% (56/637), which was the dominant epidemic gene subtype in 2014-2015, sporadic in 2016-2019, reappeared in 2022, and significantly increased in 2024 (27.27%, 24/88). Outbreaks caused by the GⅡ.17 [P17] subtype occurred mainly from October to December, with the main sites of occurrence in primary schools and kindergartens. This study yielded 53 near-complete genome sequences of the GⅡ.17 [P17] subtype from 46 incidents in Chaoyang District. The GⅡ.17 [P17] subtype sequences of Chaoyang District from 2014 to 2024 were segmented into three subgroups on the evolutionary tree, with sequences from 2014 to 2019, 2022 to April 2024, and May to December 2024 clustered into the d, e, and b subgroups, respectively. In the VP1 region′s P2 area, particularly at the HBGA binding site, subgroups b and e exhibited mutations in 22 and two sites, while subgroups b and e showed mutations in four and one sites, predominantly in the RdRp region.Conclusion:The outbreak caused by the NoV GⅡ.17 [P17] subtype in Chaoyang District from 2014 to 2024 continues, with a significant increase in 2024, and it becomes the dominant gene subtype from October to December. The sequence formation of the NoV GⅡ.17 [P17] subtype in Chaoyang District from January to April 2022 and from May to December 2024 shows two different evolutions, with specific mutation sites, requiring continuous monitoring of the NoV GⅡ.17 [P17] subtype.

Objective:To establish a fluorescent quantitative RT-PCR assay based on N_sgRNA of SARS-CoV-2 and preliminarily apply it on real samples.Methods:Recombinant plasmid, specific primers and probes of N_sgRNA were designed and synthesized based on Wuhan-Hu-1/2019_MN908947 and synthesis mechanism of subgenomic RNA (sgRNA). Using recombinant plasmid as amplification templates, the optimal reaction conditions and reaction system were screened according to the Ct value, fluorescence intensity, and shape of amplification curve and was evaluated for sensitivity, reproducibility, and specificity. Meanwhile, the possibility of practical application of the method was explored by testing 172 clinical samples and 256 municipal wastewater samples. Results:A qRT-PCR assay for N_sgRNA in SARS-CoV-2 was initially established. The detection limit of the assay was 20 copies/mL, and the variation coefficients of in-batch (0.002%~0.767%) and batch to batch repetition (0.016%~0.752%) were less than 1%. Only N_sgRNA recombinant plasmid was detected in the specificity assay. So the method is more highly sensitive, specific and reproducible. The RatiosgRNA/ gRNA of clinical samples HK.3, EG.5.1, JN.1 and their sub-lineages and their corresponding urban sewage samples in epidemic period were significantly different ( P<0.05). There is a strong correlation between the median of RatiosgRNA/ gRNA in clinical samples and sewage samples in the same period (correlation coefficient r=1.000, P=0.010). Conclusions:In this study, a qRT-PCR method for detecting N_sgRNA of SARS-CoV-2 was established and the method has the characteristics of higher sensitivity, stronger specificity and better repeatability, and it can be used to detect SARS-CoV-2 infectivity.

Objective:The SARS-CoV-2 has a high natural mutation rate, and dynamic monitoring of virus variants remains a key focus in current COVID-19 prevention and control efforts.Methods:In this study, a sensitive and rapid method for detecting SARS-CoV-2 omicron variant nucleic acid was established based on the BMD-PCR technology.Results:This method showed good specificity, and had no cross-reactivity with 11 common viruses transmitted via the respiratory and gastrointestinal tracts, and the limit of detection is 555 copies/ml. Compared with SARS-CoV-2 whole-genome sequencing result, among 50 samples with original Ct values ≤32 tested for the Omicron variant, 49 samples tested positive for the N679K mutation site using BMD-PCR Omicron variant detection, achieving a concordance rate of 98.00%. For 30 samples JN.1 lineage, 29 samples tested positive for the K356T mutation site using BMD-PCR JN.1 lineage detection, with a concordance rate of 96.67%. For 10 samples with original SARS-CoV-2 detection Ct values between 35 and 32, 7 samples tested positive for the N679K mutation site using BMD-PCR Omicron variant detection, Resultsing in a detection rate of 70.00%. For samples with SARS-CoV-2 nucleic acid detection Ct values>35, the detection rate for the N679K mutation site in the BMD-PCR Omicron variant was 20.00%.Conclusions:This method can serve as a high-throughput supplementary approach for the preliminary identification of SARS-CoV-2 variant genotypes.

Objective:To analyze the distribution and genetic characteristics of sporadic adult diarrhea virus in Chaoyang District, Beijing.Methods:Fecal samples from 177 adult patients with sporadic diarrhea were collected from 4 enteric outpatient clinics in Chaoyang District, Beijing from May to December 2019. Nucleic acid detection of Norovirus, Sappovirus, Rotavirus, Enteric Adenovirus and Astrovirus in the samples was performed by real-time quantitative PCR. The positive samples were amplified by RT-PCR/PCR and sequenced. The phylogenetic analysis was performed by neighbor-Joining (NJ) methods of Mega 6.0 software.Results:There were 60 of 177 (33.90%) adult sporadic diarrhea samples positive for enteric viral pathogens. Among them, 47 cases were infected with single virus, including 29 cases of Norovirus, 9 cases of Sappovirus, 8 cases of Astrovirus and 1 case of Enteric Adenovirus, in addition with 13 cases of multiple infections. None of rotavirus was detected. Partial sequences were successfully obtained for analysis, including 16 cases of GI Norovirus (7 subtypes and GI.3[P13] predominant), 10 cases of GII Norovirus (5 subtypes and GII.6[P7] predominant), 12 cases of Sappovirus (4 subtypes and GI.2 predominant), and 7 cases of Astrovirus (2 subtypes and AST-1 predominant).Conclusion:Norovirus, Astrovirus and Sappovirus are main pathogens among sporadic adult diarrhea in Beijing in 2019, and and different pathogenic gene subtypes show diverse characteristics.

Objective:To analyze the distribution and genetic characteristics of sporadic adult diarrhea virus in Chaoyang District, Beijing.Methods:Fecal samples from 177 adult patients with sporadic diarrhea were collected from 4 enteric outpatient clinics in Chaoyang District, Beijing from May to December 2019. Nucleic acid detection of Norovirus, Sappovirus, Rotavirus, Enteric Adenovirus and Astrovirus in the samples was performed by real-time quantitative PCR. The positive samples were amplified by RT-PCR/PCR and sequenced. The phylogenetic analysis was performed by neighbor-Joining (NJ) methods of Mega 6.0 software.Results:There were 60 of 177 (33.90%) adult sporadic diarrhea samples positive for enteric viral pathogens. Among them, 47 cases were infected with single virus, including 29 cases of Norovirus, 9 cases of Sappovirus, 8 cases of Astrovirus and 1 case of Enteric Adenovirus, in addition with 13 cases of multiple infections. None of rotavirus was detected. Partial sequences were successfully obtained for analysis, including 16 cases of GI Norovirus (7 subtypes and GI.3[P13] predominant), 10 cases of GII Norovirus (5 subtypes and GII.6[P7] predominant), 12 cases of Sappovirus (4 subtypes and GI.2 predominant), and 7 cases of Astrovirus (2 subtypes and AST-1 predominant).Conclusion:Norovirus, Astrovirus and Sappovirus are main pathogens among sporadic adult diarrhea in Beijing in 2019, and and different pathogenic gene subtypes show diverse characteristics.

Objective:To explore the diagnostic value of Caprini score for acute pulmonary embolism(APE).Methods:Totally 2 764 patients with suspected APE admitted to Yuncheng Central Hospital were enrolled from January 2012 to January 2019, and 312 patients were diagnosed APE and assigned to APE group finally.Among the patients without APE, 312 patients(control group) were matched with the patients in APE group according to age, gender, weight, blood pressure, surgical history, etc.The general clinical data of the two groups were collected, and the Caprini score of each patient was recorded.The differences between the two groups in clinical data and Caprini score were compared.The area under curves(AUC) of receiver operating characteristic(ROC) was calculated to predict the diagnostic efficacy of Caprini scale for patients with APE.Results:The Caprini score of the APE group was significantly higher than that of the control group[(5.41±2.47)points vs.(2.16±1.28)points, t=1.180, P=0.004]. The Caprini score had a favorable diagnostic efficacy for patients with suspected APE(AUC=0.915, 95% CI: 0.878-0.995, P<0.001), and when the 3.5 cutoff value of Caprini score was determined, the specificity and sensitivity were 87.76% and 95.24%, respectively, with 7.778 of positive likelihood ratio, 0.054 of negative likelihood ratio, and 0.83 of Youden index. Conclusion:Caprini score has strong diagnostic efficacy in patients with APE.

Objective: To evaluate the epidemiologic characteristics of hand, foot and mouth disease in Zhejiang province between 2009 and 2017, so that scientific evidence could be provided for prevention and control of hand, foot and mouth disease. Methods: Spatial, temporal and population distribution of HFMD was analyzed. Real-time reverse transcription polymerase cain reaction was used to test Enterovirus A71 and Coxsackievirus A16 in samples. Results: Between 2009 and 2017, 1 108 093 HFMD cases were reported in Zhejiang with the prevalence of 226.24/100000; 2010, 2012, 2014 and 2016 had a higher prevalence than other years. Prevalence of HFMD peaked in April-July and September-October. Wenzhou, Taizhou and Ningbo had a higher prevalence than other cities. In total, 69.27% cases were children who were not enrolled in nursery school, and 65.67% were 1-3 years old. Pathogen surveillance showed that EV-A71 decreased in mild cases, whereas other enterovirus increased. However EV-A71 was still predominant in severe and fatal cases (56.0%). Conclusions Temporal and spatial distribution of HFMD is characteristic in Zhejiang province. EV-A71 predominated in severe cases and fatal cases, while other enterovirus (non-EV-A71, non CV-A16) were the main pathogen for mild cases.