This study aimed to explore the application value of new biological specimen oral fluid in SARS-CoV-2 nucleic acid and antibody detection. Oral fluid and paired respiratory and blood specimens from 7 confirmed cases of two COVID-19 cluster epidemic were collected in Beijing from October to November 2021. SARS-CoV-2 virus and IgG antibody were detected by real time PCR kits and serum antibody detection reagents, and SARS-CoV-2 IgG antibody in oral fluids was detected by a new established method of magnetic particle chemiluminescence. The results showed that the nucleic acid amplification test of SARS-CoV-2 on nasopharyngeal swabs, throat swabs and oral fluid specimens from 3 confirmed cases of COVID-19 was positive, among which the Ct value for ORF1a/b and N gene of oral fluid samples in 2 cases was close to that of throat swab, and the Ct value of oral fluid sample for 1 case was higher than that of throat swab. The complete genome sequence of one oral fluid specimen was obtained, which belonged to the VOC/Delta variant strain. The SARS-CoV-2 IgG antibodies of the paired oral fluid and serum were all positive, and the S/CO values of oral fluid were all lower than those of serum. The series of oral fluid results showed that SARS-CoV-2 IgG antibody level increased from 11 to 32 days after the onset of the disease.
COVID-19/diagnosis* ; Humans ; Nucleic Acids ; SARS-CoV-2 ; Sensitivity and Specificity

Human parainfluenza viruses (HPIVs) is one of the main causes of acute respiratory tract infections in children. HPIVs have been grouped into four serotypes (HPIV1~HPIV4) according to serological and genetic variation. Different serotypes of HPIVs have diverse clinical disease spectrum, epidemic characteristics and disease burden. Based on the nucleotide variation in structural protein genes, HPIVs can be further divided into distinct genotypes and subtypes with diverse temporal and spatial distribution features. The standard molecular typing methods are helpful to clarify the gene evolution and transmission patterns of HPIVs in the process of population transmission. However, the development of molecular epidemiology of HPIVs has been hindered by the lack of a standardized molecular typing method worldwide. Therefore, this study reviewed the viral characteristics, genome structure, existing genotyping methods and evolution of HPIVs, and screened the reference strains for molecular typing, so as to improve the understanding of gene characteristics and molecular typing of HPIVs, and provide an important scientific basis for the monitoring and research of molecular epidemiology of HPIVs in China.
Child ; Humans ; Molecular Typing ; Parainfluenza Virus 1, Human/genetics* ; Parainfluenza Virus 2, Human/genetics* ; Parainfluenza Virus 3, Human/genetics* ; Paramyxoviridae Infections/epidemiology* ; Respiratory Tract Infections/epidemiology*

Since January 2022, severe acute hepatitis cases with unknown etiology in children have occurred in many countries in Europe and the United States, and 43.8% of the cases were positive for human adenovirus (HAdV), and some cases were identified as HAdV-41. However, more evidences including etiology, genomics, liver pathology, and immunohistochemistry are needed to determine the main cause of this outbreak. At present, due to the lack of systematic surveillance and research on hepatitis caused by HAdV infection, it is impossible to determine whether there are similar hepatitis cases occurred in China. It is urgent to carry out HAdV virolgocial surveillance based on clinical symptom, and potential risk of HAdV hepatitis should be studied as soon as possible according to the available relevant clinical, epidemiological and virological data, as well as risk factor information, which will provide scientific and technical support for the prevention and control of HAdV-related diseases.

Objective To identify measles vaccine failures in Tianjin,China using a measles virus IgG avidity assay.Methods The China Information System for Disease Control and Prevention (CISDCP) was used to collect information about measles cases and blood specimens in Tianjin from 2013 to 2015.Measles-specific IgM and IgG antibodies were detected using Enzyme-Linked Immunosorbent Assay (ELISA).Avidity testing for measles IgG was performed using a commercial enzyme immunoassay (EIA).Results A total of 284 confirmed measles cases were identified.Of this total,262 (92.25％) were in patients aged ≥ 20 years.High avidity was exhibited in 172 (60.56％) cases,while 80 (28.17％) cases demonstrated low avidity.High avidity was detected in only 21.43％ of cases in patients aged ＜ 1 year.The proportion of high avidity increased with age,and was significantly higher in patients aged 30-39 years at 70.07％ (x2 =17.27,P =0.002).Of the 52 measles cases in patients with a history of vaccinations,41 (78.85％) cases showed high avidity,indicating secondary vaccine failures (SVF).In these vaccinations,there was no significant difference (P ＞ 0.05) in clinical severity between high avidity and low avidity cases.However,regardless of vaccination status,clinical severity was significantly lower in high avidity cases (P ＜ 0.001) than in low avidity cases.The percentages of positive measles IgM results in high avidity and low avidity cases were 66.28％ and 91.25％,respectively.Geometric Mean Concentration (GMC) was significantly lower in high avidity cases at 33.73 U/mL,compared to 166.07 U/mL in low avidity cases.Conclusions Low clinical severity and inconclusive IgM antibody results are more likely in high avidity measles cases.Measles cases were more common in adults.Therefore,a further dose of vaccines should be recommended for 30-39 years in Tianjin.

To study the epidemic characteristics of human rhinovirus (HRV) in children with acute respiratory infections in Gansu Province. 286 throat swabs were collected from children with acute respiratory in fections in Gansu Province during 2011. Multiplex reverse transcription-PCR (multiplex RT-PCR) assay was used to screen those specimens for detection of common respiratory tract pathogens. For HRV-positive samples, nested reverse transcription polymerase chain reaction (nested RT-PCR) was performed to amplify VP1 and VP4/VP2 gene fragments of HRV. The VP4/VP2 and VP1 regions of HRV-positive samples were sequenced and performed genotype analysis. Of 286 specimens fested, 27 were positive for HRV by multiplex RT-PCR and nested RT-PCR, of which 16 children were made (16/185), 8.64%) and 11 female (11/101,10.89%). The positive rate was 9.44% (27/286). The mean age of HRV-positive children was 3 years in this study, children less than one year old had the highest proportion 44.4% (12/ 27, 44.4%). The highest HRV positive rate fell on May, 2011 (6/27, 22.2%). Common cold accounted for the highest proportion, 12.24% (12/98) followed by pneumonia, 8.50% (13/153). The remaining 2 cases were bronchitis. Sequence analysis showed HRV A was the predominant genotype in Gansu Province in 2011, accounting for 84.62% (22/26) of positive cases, followed by HRV C (11.54%, 3/26) and only one HRV B was detected (3.85%, 1/26). HRV could be detected throughout the year in Gansu Province and primarily infected children under one year old. The group A was the epidemic genotype of HRV and move than one genotype existed in Gansu Province during 2011.
Adolescent ; Child ; Child, Preschool ; China ; epidemiology ; Female ; Humans ; Infant ; Male ; Molecular Sequence Data ; Phylogeny ; Picornaviridae Infections ; epidemiology ; virology ; Respiratory Tract Infections ; epidemiology ; virology ; Rhinovirus ; classification ; genetics ; isolation & purification ; Seasons

Objective Human parainfluenza virus (HPIV) types 1,2 and 3 are major viral pathogens responsible for upper and lower respiratory tract infections.In this study,a real-time RT-PCR was developed using multiplex primers-probe (HPIV-1,2,3) for the simultaneous detection of both HPIV1,HPIV2 and HPIV3 genomes.Methods Optimal primers and probes were designed using specialized software.The conditions for multiplex real-time RT-PCR had been optimized.The synthesis of RNA standards of HPIV1,2,3 were used a T7 RNA polymerase.Check the specificity sensitivities and stability of one step RT-PCR assay.Results Obtained in a 10-fold dilution series assay demonstrate a high sensitivity of the assay with a lowest detection limit of 10 copies for HPIV1,100 copies for HPIV2 and 100 copies for HPIV3.Conclusion The assays demonstrates an improved sensitivity and scope of detecting HPIV1,2,3 viruses relative to routine antigen detection assays while the quantitative utility may facilitate investigation of the pre-diagnosis and respiratory virus pathogenesis.

Objective To understand the evolutionary relationship between the C4a evolutionary lineage of human enterovirus 71 (HEV71) strains circulating in mainland of China during 2008-2010 and 2008 Fuyang strains and study the prevalence and transmission patterns of 2008 Fuyang strains.Methods Download all the complete VP1 (≥ 891 bp) or approximate complete VP1 (≥ 876 bp) gene nucleotide sequences from GenBank of HEV71 strains circulating in Mainland of China during 2008-2010.And analyze the phylogenetic relationship between Fuyang strains and other provinces' strains using the MEGA software,version 5.0.Results All of the HEV71 isolates circulating in Mainland of China during 2008-2010 were clustered into evolutionary lineage C4a except for eight strains grouped in the genotype A and one isolate belongs to evolutionary lineage C4b; the homology analysis showed there were 96.5％-100％ identity between C4a viruses circulating in mainland China during 2008-2010 and 2008 Fuyang strains,and they were evolved from C4b viruses of 1998.The transmission chains of Fuyang strains were mainly transmitted in Guangdong,Jiangsu,Shanghai,Hunan,Shandong provinces.Conclusion The predominant viruses circulating in Mainland of China during 2008-2010 were evolutionary lineage C4a of human Enterovirus 71 ;Fuyang transmission chains mainly distributed in southern of China and the Central China around Anhui provinces.

Common Cold ; drug therapy ; epidemiology ; virology ; Humans ; Rhinovirus ; genetics ; isolation & purification

A GeXP based multiplex RT-PCR assay was developed to simultaneously detect twelve different respiratory viruses types/subtypes including influenza A virus, influenza B virus, influenza A virus sH1N1, parainfluenza virus type 1, parainfluenza virus type 2, parainfluenza virus type 3, human rhinovirus, human metapneumovirus, adenovirus, respiratory syncytial virus A, respiratory syncytial virus B and human bocavirus. Twelve sets of specific primers were designed based on the conserved sequences of available respiratory-virus sequence database. The specificity of the multiplex system was examined by positive specimens confirmed previously. The sensitivity to detect twelve respiratory viruses simultaneously was 10(3) copies/microL. Twenty four clinical specimens were further detected by this novel assay and the results were compared with that of the real-time RT-PCR. These results showed that this novel assay based on GeXP is a fast, sensitive, and high throughput test for the detection of respiratory virus infections.
Humans ; Influenza A Virus, H1N1 Subtype ; genetics ; isolation & purification ; Orthomyxoviridae ; genetics ; isolation & purification ; Orthomyxoviridae Infections ; virology ; RNA Viruses ; genetics ; isolation & purification ; Real-Time Polymerase Chain Reaction ; instrumentation ; methods ; Respiratory Syncytial Viruses ; genetics ; isolation & purification ; Respiratory Tract Infections ; virology ; Reverse Transcriptase Polymerase Chain Reaction ; instrumentation ; methods ; Rhinovirus ; genetics ; isolation & purification ; Sensitivity and Specificity

Objective We want to explore the harm degree of human rhinovirus in infants in Beijing area. Methods From May 2008 to September 2009,240 nasopharyngeal aspirates were collected from the children and infants who were hospitalized and with lower respiratory tract infections. These specimens were screened for HRV by real-time reverse transcription PCR(RT-PCR) and statistically analysised. Result In all of 240 hospitalized children, 208 cases were admission diagnosis of pneumonia, accounting for 86.67% (208/240), no deaths, the ratio of male and female patients was 1.93: 1, and the collected samples reached to a maximum number in February 2009. Real-time PCR used to detect human rhinovirus, positive samples number is 71, positive rate is 29. 58% (71/240) ,and the main symptoms and clinical diagnosis was pneumonia. Most cases were less than 2 years old, making up 81.69% (58/71), amony them, 13 months-18 months age and ≥ 24 months groups have the highest incidence rates, the incidence rate is 33.33%.Conclusion Human rhinovirus happened in spring and winter seasons, especially the infants who were under 2 years are the main infection groups, the important symptoms are lower respiratory infections such as pneumonia, bronchitis and bronchiolitis et al. Human rhinovirus is seasonal and contagious, spreads fast, so protective measures in hospitals should be prepared to avoid cross-infection.