Characterization of genetic variants in children with refractory epilepsy / 中华医学遗传学杂志

OBJECTIVE@#To analyze the characteristics of genetic variants among children with refractory epilepsy (RE).@*METHODS@#One hundred and seventeen children with RE who had presented at the Affiliated Jinhua Hospital of Zhejiang University School of Medicine from January 1, 2018 to November 21, 2019 were selected as the study subjects. The children were divided into four groups according to their ages of onset: < 1 year old, 1 ~ 3 years old, 3 ~ 12 years old, and >= 12 years old. Clinical data and results of trio-whole exome sequencing were retrospectively analyzed.@*RESULTS@#In total 67 males and 50 females were included. The age of onset had ranged from 4 days to 14 years old. Among the 117 patients, 33 (28.21%) had carried pathogenic or likely pathogenic variants. The detection rates for the < 1 year old, 1 ~ 3 years old and >= 3 years old groups were 53.85% (21/39), 12.00% (3/25) and 16.98% (9/53), respectively, with a significant difference among the groups (χ2 = 19.202, P < 0.001). The detection rates for patients with and without comorbidities were 33.33% (12/36) and 25.93% (21/81), respectively (χ2 = 0.359, P = 0.549). Among the 33 patients carrying genetic variants, 27 were single nucleotide polymorphisms (SNPs) or insertion/deletions (InDels), and 6 were copy number variations (CNVs). The most common mutant genes were PRRT2 (15.15%, 5/33) and SCN1A (12.12%, 4/33). Among children carrying genetic variants, 72.73% (8/11) had attained clinical remission after adjusting the medication according to the references.@*CONCLUSION@#28.21% of RE patients have harbored pathogenic or likely pathogenic variants or CNVs. The detection rate is higher in those with younger age of onset. PRRT2 and SCN1A genes are more commonly involved. Adjusting medication based on the types of affected genes may facilitate improvement of the remission rate.

Analysis of genetic variants in a case with Rotor syndrome / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a patient featuring Rotor syndrome.@*METHODS@#Clinical data of the patient was collected. Whole exome sequencing (WES) based on high-throughput sequencing technology was carried out. Long-interspersed element-1 (LINE-1) insertion in intron 5 of the SLCO1B3 gene was detected by using tri-primer single tube PCR.@*RESULTS@#WES revealed that the patient has carried homozygous c.1738C>T nonsense variants of the SLCO1B1 gene. He was also found to harbor a homozygous insertion of LINE-1 in intron 5 of the SLCO1B3 gene, which has caused skipping of exon 5 or exons 5 to 7 and introduced a stop codon in the SLCO1B3 transcript.@*CONCLUSION@#The homozygous c.1738C>T variant of the SLCO1B1 gene and homozygous insertion of LINE-1 in intron 5 of the SLCO1B3 gene probably underlay the Rotor syndrome in this patient.

Effects of pre-existing antibody on seroconversion rate after influenza vaccination / 中华微生物学和免疫学杂志

Objective:To investigate the effects of pre-existing antibody on seroconversion rate after influenza vaccination.Methods:This study recruited 1 900 healthy volunteers to receive influenza split vaccines in Xinjiang Uygur Autonomous region and Yunnan Province from September 2009 to October 2018. Hemagglutinin agglutination inhibition assay was used to detect the titers of specific antibodies in blood samples collected before vaccination and 28 d after vaccination and the effects of pre-existing antibody on the seroconversion to different influenza vaccine components were analyzed.Results:Trend analysis showed that with the increasing titer of pre-existing antibody, the seroconversion rates to A/H1N1, A/H3N2, B/Victoria and B/Yamagata vaccine components were gradually decreased (χ 2=121.76, P<0.001; χ 2=67.58, P<0.001; χ 2=45.25, P<0.001; χ 2=54.55, P<0.001). After adjusting for factors such as region, gender and age, multivariate logistic regression showed that pre-existing antibody titer equal to or higher than 40 was an independent factor that affected the seroconversion to A/H1N1, A/H3N2 and B/Victoria vaccine components, and the adjusted OR (95%CI) values were 2.50(2.00-3.13)、1.64(1.35-2.00) and 2.50(1.79-3.45), respectively. Conclusions:The seroconversion rate to each vaccine component was negatively correlated with the pre-existing antibody titer. The factor that pre-existing antibody titer equal to or higher than 40 was detrimental to the seroconversion to A/H1N1, A/H3N2 and B/Victoria vaccine components, but had no significant influence on B/Yamagata seroconversion.

Analysis of ANKRD11 gene variant in a family affected with KBG syndrome / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a pedigree affected with KBG syndrome.@*METHODS@#Clinical data of three patients from the pedigree (the proband, his mother and sister) was collected. Genomic DNA was extracted from peripheral blood samples and subjected to whole exome sequencing (WES). Suspected variant was verified by Sanger sequencing.@*RESULTS@#The proband was found to harbor a heterozygous c.4398_4401del (p.Glu1467AsnfsTer63) frameshift variant of the ANKRD11 gene by WES. Sanger sequencing confirmed that the same variant was also present in his mother and sister, but not in his father.@*CONCLUSION@#The c.4398_4401de (p.Glu1467AsnfsTer63) variation of the ANKRD11 gene probably underlies the KBG syndrome in this pedigree.

Research progress in establishing baselines and thresholds of influenza epidemic / 中华预防医学杂志

Influenza is an acute respiratory infection that seriously harms the world and public health. Because influenza viruses are prone to mutations and difficult to predict, the World Health Organization has been promoting global continuous strengthening of influenza surveillance to monitor the level of influenza activity and epidemic trends in real time. Establishing baselines and thresholds for influenza epidemic helps to gauge the start and severity of influenza seasons. At present, there are various methods for calculating baseline and threshold, such as annual median value, percentile approach, moving epidemic method, and control chart method. This paper will summarize the methods of establishing influenza baseline or threshold at home and abroad, and hope to provide reference for the establishment of baseline or threshold of influenza in China.

Evaluation of the application of moving epidemic method on making influenza epidemic thresholds in the 7 climate zones in China / 中华预防医学杂志

Objective@#We planned to evaluate the effectiveness of moving epidemic method (MEM) in calculating influenza epidemic threshold of 7 climatic zones in China mainland.@*Methods@#The positive rate of influenza virus was obtained from the National Influenza Surveillance Network System from 2010/2011 to 2017/2018. We divided the 31 provinces into 7 climatic zones according to previous literatures and applied MEM to calculate the influenza epidemic threshold of 2018/2019 influenza season for these climatic zones. Sensitivity, specificity, positive predictive value and negative predictive value were calculated to evaluate the effectiveness of MEM.@*Results@#Pre-epidemic threshold (the positive rate of influenza virus) varied from 9.66% (temperate zone) to 16.36% (subtropical zone) for 2018/2019 influenza season. The gap between pre-epidemic and post-epidemic thresholds was less than 5% except for plateau zone. The sensitivity was 86.16% (95CI:66.81%-98.23%), the specificity was 94.92% (95CI: 91.13%-98.41%), the positive predictive value was 89.87% (95%CI: 84.39%-94.38%), the negative predictive value was 92.96% (95%CI: 84.46%-99.17%).@*Conclusion@#Overall, moving epidemic Method performs well in calculating influenza epidemic threshold in China, much better than the previous study.

Influenza-like illness outbreaks in China during 2017-2018 surveillance season / 中华预防医学杂志

Objective@#To analyze epidemiological characteristics of influenza-like illness outbreaks in mainland China during 2017-2018 surveillance season, and to provide scientific evidence for developing influenza prevention and control strategies.@*Methods@#We collected the data on reported influenza outbreaks in 2017-2018 surveillance season from China Influenza Surveillance Information System and China Public Health Emergency Management Information System and analyzed the data of laboratory-confirmed influenza-like illness outbreaks by descriptive epidemiological methods.@*Results@#During the surveillance season, a total of 2 398 influenza-like illness outbreaks (with 10 or more incidences in an outbreak) in mainland China were reported, involving 87 084 patients, of which 2 323 were influenza outbreaks, involving 85 531 patients. The reported influenza-like illness outbreaks occurred most frequently from November 2017 to January 2018 in both the southern and northern regions and the highest peaks were in December 2017. During the period 1 850 influenza-like illness outbreaks (77.15%) were reported in the southern region, and 548 influenza-like illness outbreaks (22.85%) were reported in the northern region. The most of the outbreaks occurred in primary, secondary schools and nursery care schools, with a total of 2 210 reports (92.16%). And the majority of the outbreaks involved 10-29 incident cases. The dominant isolated virus strains for the outbreaks were influenza B (1 505 outbreaks, 62.76% of all the outbreaks).@*Conclusion@#Seasonality of influenza outbreaks were observed in mainland China during 2017-2018 surveillance season and the reported influenza outbreaks were most frequently occurred in autumn-winter season and in southern China. Primary, secondary schools and nursery care schools are high-risk places for outbreaks, and the dominant isolated virus strains for the outbreaks were influenza B.

Technical guidelines for seasonal influenza vaccination in China, 2018-2019 / 中华流行病学杂志

Seasonal influenza vaccination is the most effective way to prevent influenza virus infection and its complications.Currently,China has licensed trivalent (IIV3) and quadrivalent inactivated influenza vaccine (IIV4),including split-virus influenza vaccine and subunit vaccine.In most parts of China,influenza vaccine is a category Ⅱ vaccine,which means influenza vaccination is voluntary,and recipients need to pay for it.To strengthen the technical guidance for prevention and control of influenza and the operational research on influenza vaccination in China,the National Immunization Advisory Committee (NIAC),Influenza Vaccine Technical Working Group (TWG),updated the 2014 technical guidelines and compiled the "Technical guidelines for seasonal influenza vaccination in China (2018-2019)",based on most recent existing scientific evidences.The main updates include:epidemiology and disease burden of influenza,types of influenza vaccines,northern hemisphere influenza vaccination composition for the 2018-2019 season,and,IIV3 and IIV4 vaccines' major immune responses,durability of immunity,immunogenicity,vaccine efficacy,effectiveness,safety,cost-effectiveness and cost-benefit.The recommendations include:Points of Vaccination clinics (PoVs) should provide influenza vaccination to all persons aged 6 months and above who are willing to be vaccinated and do not have contraindications.No preferential recommendation is made for any influenza vaccine product for persons who can accept ≥ 1 licensed,recommended,and appropriate products.To decrease the risk of severe infections and complications due to influenza virus infection among high risk groups,the recommendations prioritize seasonal influenza vaccination for children aged 6-60 months,adults ≥60 years of age,persons with specific chronic diseases,healthcare workers,the family members and caregivers of infants ＜6 months of age,and pregnant women or women who plan to pregnant during the influenza season.Children aged 6 months to 8 years old require 2 doses of influenza vaccine administered a minimum of 4 weeks apart during their first season of vaccination for optimal protection.If they were vaccinated in previous influenza season,1 dose is recommended.People ≥ 9 years old require 1 dose of influenza vaccine.It is recommended that people receive their influenza vaccination by the end of October.Influenza vaccination should be offered as soon as the vaccination is available.Influenza vaccination should continue to be available for those unable to be vaccinated before the end of October during the whole season.Influenza vaccine is also recommended for use in pregnant women during any trimester.These guidelines are intended for CDC members who are working on influenza control and prevention,PoVs members,healthcare workers from the departments of pediatrics,internal medicine,and infectious diseases,and members of materuity and child care institutions at all levels.

The influence of statutory holidays on the proportion of the outpatient and emergency visits for influenza-like illness / 中华流行病学杂志

Objective To analyze the reasons for the fluctuations in the percentage of outpatient or emergency visits for influenza-like illness (ILI) during the Spring Festival and National Day in 2014-2018 surveillance season.Methods ILI surveillance data was collected during the period of Spring Festival and National Day in mainland China,and downloaded from Chinese Influenza Surveillance Information System,during the 2014-2018 surveillance season.Results There was no significant difference noticed in the number of ILI reports in the festival week with weeks before or after in both the southern and northern provinces.The number of outpatient visits was much less than that of the week before and after,but the number of emergency visits was statistically significantly increased.Conclusion In the holiday peak of ILI％,the major causes was the impact of holiday-off at sentinel hospitals,resulting in a large reduction in the number of outpatient visits in the consulting room during the festivals.

Current situation and related policies on the implementation and promotion of influenza vaccination, in China / 中华流行病学杂志

Influenza can be prevented through annual appropriate vaccination against the virus concerned.In China,influenza vaccine is categorized as "Class Ⅱ " infectious diseases which the cost is paid out of the user's pockets.The annual coverage of influenza vaccination had been 2％-3％.The main reasons for the low coverage would include the following factors:lacking awareness on both the disease and vaccine,poor accessibility of vaccination service,and the cost of vaccination.To reduce the health and economic burden associated with influenza,comprehensive policies should be improved,targeting the coverage of seasonal influenza vaccination.These items would include:① Different financing reimbursement schemes and mechanisms to improve the aspiration on vaccination and on the vaccine coverage in high-risk groups,as young children,elderly,people with underlying medical conditions;② to ameliorate equality of vaccination services;③ to improve knowledge of the health care workers (HCWs) and the public on influenza and related vaccines;④ to improve clinical and preventive medical practice and vaccination among HCWs through revising clinical guidelines,pathway and consensus of experts;⑤ to provide more convenient,accessible and normative vaccination service system;⑥ to strengthen research and development as well as marketing on novel influenza vaccines;⑦ to revise items regarding the contraindication for influenza vaccine on pregnancy women,stated in the Chinese Pharmacopoeia.

Development and prospect of Influenza Surveillance Network in China / 中华流行病学杂志

The annual seasonal epidemic of influenza caused serious disease burden around the world,and serious social panic and economic losses.Due to the high variability and uncertainty of influenza virus,prevention and control of influenza faces many challenges.Surveillance is a key strategy to prevent and control influenza,and influenza is the first infectious disease to be monitored globally.More than 60 years,influenza surveillance programs in China has made great contributions to the prevention and control of influenza in China and the world.Especially in the past 10 years,the influenza surveillance network has developed rapidly,the scale has been expanded significantly,the monitoring content and scope have been continuously improved,and the monitoring quality has been rapidly improved.The China Influenza Surveillance Network is one of the early detection systems for emerging infectious diseases in China and the world.It helps to improve the capacity of public health system in prevention and control and early warning of emerging infectious diseases.

Technical guidelines for seasonal influenza vaccination in China, 2018-2019 / 中华流行病学杂志

Seasonal influenza vaccination is the most effective way to prevent influenza virus infection and its complications.Currently,China has licensed trivalent (IIV3) and quadrivalent inactivated influenza vaccine (IIV4),including split-virus influenza vaccine and subunit vaccine.In most parts of China,influenza vaccine is a category Ⅱ vaccine,which means influenza vaccination is voluntary,and recipients need to pay for it.To strengthen the technical guidance for prevention and control of influenza and the operational research on influenza vaccination in China,the National Immunization Advisory Committee (NIAC),Influenza Vaccine Technical Working Group (TWG),updated the 2014 technical guidelines and compiled the "Technical guidelines for seasonal influenza vaccination in China (2018-2019)",based on most recent existing scientific evidences.The main updates include:epidemiology and disease burden of influenza,types of influenza vaccines,northern hemisphere influenza vaccination composition for the 2018-2019 season,and,IIV3 and IIV4 vaccines' major immune responses,durability of immunity,immunogenicity,vaccine efficacy,effectiveness,safety,cost-effectiveness and cost-benefit.The recommendations include:Points of Vaccination clinics (PoVs) should provide influenza vaccination to all persons aged 6 months and above who are willing to be vaccinated and do not have contraindications.No preferential recommendation is made for any influenza vaccine product for persons who can accept ≥ 1 licensed,recommended,and appropriate products.To decrease the risk of severe infections and complications due to influenza virus infection among high risk groups,the recommendations prioritize seasonal influenza vaccination for children aged 6-60 months,adults ≥60 years of age,persons with specific chronic diseases,healthcare workers,the family members and caregivers of infants ＜6 months of age,and pregnant women or women who plan to pregnant during the influenza season.Children aged 6 months to 8 years old require 2 doses of influenza vaccine administered a minimum of 4 weeks apart during their first season of vaccination for optimal protection.If they were vaccinated in previous influenza season,1 dose is recommended.People ≥ 9 years old require 1 dose of influenza vaccine.It is recommended that people receive their influenza vaccination by the end of October.Influenza vaccination should be offered as soon as the vaccination is available.Influenza vaccination should continue to be available for those unable to be vaccinated before the end of October during the whole season.Influenza vaccine is also recommended for use in pregnant women during any trimester.These guidelines are intended for CDC members who are working on influenza control and prevention,PoVs members,healthcare workers from the departments of pediatrics,internal medicine,and infectious diseases,and members of materuity and child care institutions at all levels.

The influence of statutory holidays on the proportion of the outpatient and emergency visits for influenza-like illness / 中华流行病学杂志

Objective To analyze the reasons for the fluctuations in the percentage of outpatient or emergency visits for influenza-like illness (ILI) during the Spring Festival and National Day in 2014-2018 surveillance season.Methods ILI surveillance data was collected during the period of Spring Festival and National Day in mainland China,and downloaded from Chinese Influenza Surveillance Information System,during the 2014-2018 surveillance season.Results There was no significant difference noticed in the number of ILI reports in the festival week with weeks before or after in both the southern and northern provinces.The number of outpatient visits was much less than that of the week before and after,but the number of emergency visits was statistically significantly increased.Conclusion In the holiday peak of ILI％,the major causes was the impact of holiday-off at sentinel hospitals,resulting in a large reduction in the number of outpatient visits in the consulting room during the festivals.

Current situation and related policies on the implementation and promotion of influenza vaccination, in China / 中华流行病学杂志

Influenza can be prevented through annual appropriate vaccination against the virus concerned.In China,influenza vaccine is categorized as "Class Ⅱ " infectious diseases which the cost is paid out of the user's pockets.The annual coverage of influenza vaccination had been 2％-3％.The main reasons for the low coverage would include the following factors:lacking awareness on both the disease and vaccine,poor accessibility of vaccination service,and the cost of vaccination.To reduce the health and economic burden associated with influenza,comprehensive policies should be improved,targeting the coverage of seasonal influenza vaccination.These items would include:① Different financing reimbursement schemes and mechanisms to improve the aspiration on vaccination and on the vaccine coverage in high-risk groups,as young children,elderly,people with underlying medical conditions;② to ameliorate equality of vaccination services;③ to improve knowledge of the health care workers (HCWs) and the public on influenza and related vaccines;④ to improve clinical and preventive medical practice and vaccination among HCWs through revising clinical guidelines,pathway and consensus of experts;⑤ to provide more convenient,accessible and normative vaccination service system;⑥ to strengthen research and development as well as marketing on novel influenza vaccines;⑦ to revise items regarding the contraindication for influenza vaccine on pregnancy women,stated in the Chinese Pharmacopoeia.

Development and prospect of Influenza Surveillance Network in China / 中华流行病学杂志

The annual seasonal epidemic of influenza caused serious disease burden around the world,and serious social panic and economic losses.Due to the high variability and uncertainty of influenza virus,prevention and control of influenza faces many challenges.Surveillance is a key strategy to prevent and control influenza,and influenza is the first infectious disease to be monitored globally.More than 60 years,influenza surveillance programs in China has made great contributions to the prevention and control of influenza in China and the world.Especially in the past 10 years,the influenza surveillance network has developed rapidly,the scale has been expanded significantly,the monitoring content and scope have been continuously improved,and the monitoring quality has been rapidly improved.The China Influenza Surveillance Network is one of the early detection systems for emerging infectious diseases in China and the world.It helps to improve the capacity of public health system in prevention and control and early warning of emerging infectious diseases.

Characterization and analysis of VH1-2-encoded heterosubtypic antibodies isolated from an avian H5N1 patient / 中华实验和临床病毒学杂志

Objective@#To isolate the cross-reactive antibodies against hemagglutinin of influenza virus and identify its biological function.@*Methods@#The antibodies gene reservoir of cross-reactive and H5N1 pseudotype particles neutralizing B cell circulating in peripheral blood of a human H5N1 case was recovered by in vitro B cell culture, screening, RT-PCR and expression vector cloning techniques. The Ab gene pairing was screened by transient transfection of human kidney 293T cells and detected using ELISA and neutralization test. The heterosubtypic antibodies were prepared and characterized.@*Results@#We discovered the VH1-2-based heterosubtypic antibodies from two B cell lineages could neutralize GX-H5N1 pseudotype particles and have broader binding with Group 1 (including H1, H5, H6 and H9) and H7 subtype.@*Conclusions@#Cross-reactive antibodies can be induced by H5N1 infection.

Technical guidelines for seasonal influenza vaccination in China (2018-2019) / 中华预防医学杂志

Seasonal influenza vaccination is the most effective way to prevent influenza virus infection and complications from infection. Currently, China has licensed trivalent inactivated influenza vaccine (IIV3) and quadrivalent inactivated influenza vaccine (IIV4), including split-virus influenza vaccine and subunit vaccine. Except for a few major cities, influenza vaccine is a category Ⅱ vaccine, which means influenza vaccination is voluntary, and recipients must pay for it. To strengthen the technical guidance for prevention and control of influenza and operational research on influenza vaccination in China, the National Immunization Advisory Committee (NIAC) Influenza Vaccine Technical Working Group (TWG), updated the 2014 technical guidelines and compiled the "Technical guidelines for seasonal influenza vaccination in China (2018-2019)" . The main updates in this version include: epidemiology, disease burden, types of influenza vaccines, northern hemisphere influenza vaccination composition for the 2018-2019 season, IIV3 and IIV4 immune response, durability of immunity, immunogenicity, vaccine efficacy, effectiveness, safety, cost-effectiveness and cost-benefit. The influenza vaccine TWG provided the recommendations for influenza vaccination for the 2018-2019 influenza season based on existing scientific evidence. The recommendations described in this report include the following: Points of Vaccination clinics (PoVs) should provide influenza vaccination to all persons aged 6 months and above who are willing to be vaccinated and do not have contraindications. No preferential recommendation is made for one influenza vaccine product over another for persons for whom more than one licensed, recommended, and appropriate product is available. To decrease the risk of severe infections and complications due to influenza virus infection among high risk groups, the recommendations prioritize seasonal influenza vaccination for children aged 6-59 months, adults ≥60 years of age, persons with specific chronic diseases, healthcare workers, the family members and caregivers of infants <6 months of age, and pregnant women or women who plan to become pregnant during the influenza season. Children aged 6 months through 8 years require 2 doses of influenza vaccine administered a minimum of 4 weeks apart during their first season of vaccination for optimal protection. If they were vaccinated in 2017-2018 influenza season or a prior season, 1 dose is recommended. People more than 8 years old require 1 dose of influenza vaccine. It is recommended that people receive their influenza vaccination by the end of October. Influenza vaccination should be offered as soon as the vaccination is available. For the people unable to be vaccinated before the end of October, influenza vaccination will continue to be offered for the whole season. Influenza vaccine is also recommended for use in pregnant women during any trimester. These guidelines are intended for use by staff members of the Centers for Disease Control and Prevention at all levels who work on influenza control and prevention, PoVs staff members, healthcare workers from the departments of pediatrics, internal medicine, and infectious diseases, and staff members of maternity and child care institutions at all levels.

Preparation and identification of influenza H1N1 subtype vaccine candidate strain in China / 中华实验和临床病毒学杂志

Objective@#Influenza H1N1 subtype vaccine candidate strains from a 2015—2016 year epidemic strain in China were prepared and identified by themethod of classical reassortment.@*Methods@#The influenza H1N1 epidemic strain and H3N2 high-yield reassortant parental strain (X-157) were mixed and inoculated into embryonated chicken eggs by the classical reassortmentmethod . The negative selection of mixed culture virus was carried out with the antiserum of H3 protein and the antiserum of X-157 strain. Real-time PCRmethod was used to test the HA and NA genes. Restriction enzyme digestionmethod was used to identify the internal genes. HA and NA genes of selected strains were sequenced. The strain which HA and NA genes possessed the same amino acid constitution with the wild type virus was selected and immunized to ferret. Two-way test was carried out.@*Results@#Five strains with expected HA and NA genes were selected by real-time PCR. Internal genes were identified, with 4 strains had 6+ 2 constitution, 1 strain had 5+ 3 constitution. Comparing with the wild type virus, HA and NA genes of the 5 strains had no mutation. HA titer of reassortant strains was above 1 024. HI titer of the selected NO.12 reassortment strain reached 5 120, and two-way test was passed. The yield of reassortant strain was 64 times that of the wild type strain.@*Conclusions@#A circulating influenza A (H1N1) strain of influenza A (2015—2016) was successfully prepared in China and laid the foundation for vaccine storage and disease prevention and control.

Generation and preliminary characterization of monoclonal antibodies against neuraminidase of H7N9 subtype influenza A virus / 中华实验和临床病毒学杂志

Objective@#To develop the monoclonal antibody (mAb) against neuraminidase of H7N9 subtype influenza A virus and identify its biological function.@*Methods@#Female 8 week-old BALB/c mice were immunized and the splenocytes of the mice were fused with Sp2/0 myeloma cells. Indirect ELISA was used to screen hybridoma and the positive clones were subject to be subcloned. Positive clones were identified and the monoclonal antibodies(mAbs) were obtained by purifying the ascetic fluid of mice injected with the hybridoma. The NA-binding as well as neuraminidase-inhibition activity of these mAbs were determined.@*Results@#Three mAbs against neuraminidase of H7N9 subtype influenza A virus, 1G8, 3C4 and 4E8, were obtained. They demonstrated different epitop-recognizing. 3C4 and 4E8 exhibited neuraminidase inhibitory activity, with a IC50 of 1.45 μg/ml and 8.65 μg/ml, respectively.@*Conclusions@#The results suggested that mAbs specific to neuraminidase of H7N9 subtype influenza A virus were developed, providing an useful tool in control and preventing the novel H7N9 influenza A virus.

Sudden increase in human infection with avian influenza A(H7N9) virus in China, September–December 2016

Since the first outbreak of avian influenza A(H7N9) virus in humans was identified in 2013, there have been five seasonal epidemics observed in China. An earlier start and a steep increase in the number of humans infected with H7N9 virus was observed between September and December 2016, raising great public concern in domestic and international societies. The epidemiological characteristics of the recently reported confirmed H7N9 cases were analysed. The results suggested that although more cases were reported recently, most cases in the fifth epidemic were still highly sporadically distributed without any epidemiology links; the main characteristics remained unchanged and the genetic characteristics of virus strains that were isolated in this epidemic remained similar to earlier epidemics. Interventions included live poultry market closures in several cities that reported more H7N9 cases recently.