OBJECTIVEThis report presented an overview on the epidemiology of enterovirus in Yunnan province, the People's Republic of China.

METHODSA total of 210 strains of non-polioviruses isolated under acute flaccid paralysis surveillance during a 5-year study period from 1997 to 2000 and 2004 were examined. Of the 210 non-polioviruses strains, a total of 12 strains of adenoviruses were serologically identified. The remaining 198 isolates were used for molecular typing, and the viral genomes of 195 nonpolio enteroviruses (NPEVs) were translated to corresponding amino acid sequences and compared with those of the prototype strains.

RESULTSBased on molecular typing, 5 isolates were classified into 5 serotypes of human enterovirus A species while 158 isolates into 34 serotypes of B and 32 isolates into 6 serotypes of C species. However, we did not isolate any viruses which belonged to human enterovirus D species. Thus, under acute flaccid paralysis surveillance, human enterovirus B species accounted for 75.2% of the 210 isolates and was considered as the predominant one, followed by human enterovirus C (12.2%), adenovirus (5.7%), and human enterovirus A (2.4%).

CONCLUSIONAlthough the epidemiological characteristics of NPEVs from Yunnan province remained "unknown", the molecular typing method had provided us a breakthrough to understand the epidemiology of these viruses.

China ; epidemiology ; Enterovirus ; classification ; genetics ; isolation & purification ; Enterovirus Infections ; epidemiology ; Genes, Viral ; Humans ; Molecular Epidemiology ; Serotyping

Objective: To analyze the epidemiological characteristics of hand, foot and mouth disease (HFMD) among people ≥6 years old in Beijing from 2011 to 2020. Methods: The incidence data of HFMD cases from 2011 to 2020 were collected from the National Notifiable Infectious Disease Reporting System of China Information for Disease Control and Prevention and the etiological surveillance of HFMD in 29 sentinel hospitals from 16 districts of Beijing. Descriptive epidemiological methods were used to analyze the distributions, pathogen constituents, and changes of HFMD cases in Beijing people ≥6 years old. Results: From 2011 to 2020, a total of 38 183 cases of HFMD were reported among people ≥6 years old in Beijing, of which 46 (0.12%) cases were severe. The average annual reported incidence was 19.04/100 000. The ratio of males to females were 1.37∶1(22 064∶16 119). The proportion of HFMD in people ≥6 years old increased from 7.56%(2 606/34 488) in 2011 to 24.54% (546/2 225) in 2020. The average incidence of HFMD was higher in Shunyi district, Yanqing district, and Tongzhou district than in other districts in Beijing. The positive rate of enterovirus in sentinel surveillance was 66.78% (1 976/2 959), the proportion of enterovirus group A 71 (EV-A71) was 45.29% (101/223) in 2014, no EV-A71 positive was detected in 2020, and the proportion of Coxsackievirus A 6 (CV-A6) increased from 15.11% (34/225) in 2016 to 81.08% (60/74) in 2020. Conclusions: From 2011 to 2020, the proportion of cases with HFMD in people ≥6 years old in Beijing increased yearly, and the proportion of EV-A71 positive patients decreased basically. Since 2016, CV-A6 has gradually become the dominant pathogen. More attention should be paid to the epidemic situation and dynamic pathogen changes of hand foot mouth disease in people ≥6 years old.
Child ; China/epidemiology* ; Enterovirus ; Enterovirus A, Human ; Enterovirus Infections/epidemiology* ; Female ; Hand, Foot and Mouth Disease/epidemiology* ; Humans ; Infant ; Male

China ; epidemiology ; Enterovirus A, Human ; genetics ; isolation & purification ; Enterovirus Infections ; diagnosis ; drug therapy ; epidemiology ; etiology ; Humans

Objective: To understand the infection status of Enterovirus (EV) in cases of acute respiratory infections (ARIs) in Luohe City, Henan Province from 2017 to 2021, and analyze the prevalence and type composition of EV in ARIs. Methods: From October 2017 to May 2021, pharyngeal swab samples were collected from 1 828 patients with ARIs in Luohe Central Hospital and the clinical epidemiological data of these cases were also collected. EV-positive samples were identified by Quantitative Real-time Polymerase Chain Reaction (qPCR). The 5'-untranslated region (5'UTR) was amplified by Reverse Transcription-Polymerase Chain Reaction (RT-PCR). The results of 5'UTR region were initially typed by Enterovirus Genotyping Tool Version 1.0. Based on the typing results, the full-length of VP1 region was amplified by RT-PCR. The EV typing was identified again by VP1 region. Results: Among 1 828 cases of ARIs, 56.7% (1 036) were males. The median (Q₁, Q₃) age was about 3 (1, 5) years. Patients under 5 years old accounted for 71.6% (1 309 cases). Among all cases, a total of 71 EV-positive samples were identified by qPCR, with a detection rate of 3.88% (71/1 828). The EV detection rates for men and women were 3.28% (34/1 036) and 4.67% (37/792), without statistically significant differences (χ²=2.32, P=0.14). The EV detection rates for 2 to <6 years, 6 months to <2 years, 6 to <10 years, and <6 months were 6.29% (48/763), 3.00% (18/600), 2.52% (4/159), and 1.67% (1/60) (χ²=27.91, P<0.001). The EV detection rate was 0.92% (3/326) in autumn and winter of 2017. The EV detection rates were 1.18% (6/508), 2.47% (12/485) and 8.31% (34/409) in each year from 2018 to 2020, with an increasing trend year by year(χ²_trend=29.76, P<0.001). The main prevalent seasons were summer and autumn. The detection rate in spring of 2021 was 4.00% (4/100). A total of 12 types were identified and classified as CVA2, CVA4, CVA5, CVA6, CVA10, CVB3, CVB5, E5, E11, E30, PV-1, and EV-D68. The types of CVA2, CVA10, CVA6, and CVB3 were the dominant phenotypes. In 59 sample of EV typing, the main clinical manifestation was upper respiratory tract infection (36/59, 61.01%). The dominant types detected in upper respiratory tract infections were CVA10 (10/36, 27.78%), CVA6 (9/36, 25.00%) and CVB3 (8/36, 22.22%). The dominant type detected in lower respiratory tract infections was CVA2 (7/19, 36.84%). Conclusion: In Luohe City, Henan Province from 2017 to 2021, EV infection in ARIs cases has clear seasonal and age-specific patterns, and the dominant types of upper and lower respiratory tract infections are different.
Male ; Female ; Humans ; Enterovirus/genetics* ; 5' Untranslated Regions ; Enterovirus Infections/epidemiology* ; Phenotype ; Antigens, Viral/genetics* ; Respiratory Tract Infections/epidemiology* ; Phylogeny

OBJECTIVE: To describe the epidemiological and etiological characteristics of hand, foot and mouth disease (HFMD) among children aged 5 years and younger in Ningbo after the access of entero-virus-A71 vaccine (2016 to 2019). METHODS: A retrospective cohort study were performed in children aged 5 years and younger in Ningbo from 2016 to 2019. Data for incidence of HFMD was collected from the National Notifiable Disease Surveillance Reporting System and the Electronic Medical Records (EMRs) System, while the demographic information was derived from the Immunization Information System. Speci-mens were detected by real-time fluorescence quantitative PCR and the Wilson method was used to estimate the incidence rate and 95% confidence interval. RESULTS: From 2016 to 2019, a total of 1 044 800 residential children were observed in this population-based cohort. In the study, 102 471 cases of HFMD were diagnosed in 2 651 081 person-years, revealing an overall incidence density of 3 865.25/100 000 person-years. There was no significant decline in the number of the cases after the vaccine was available. The number of the patients of hand foot mouth disease during the four years was 93 421, of whom 84 875 (90.85%) had only one incident record, while 8 946 (9.15%) had 2 or more cases in this period; there were 69 771 (66.06%) patients who only needed to see a doctor once for each disease, 19.92% of the patients needed to be treated twice, and 14 801 (14.02%) patients needed to go to the hospital or clinic three times or more. The incidence of HFMD showed obvious seasonality and periodicity, which mainly concentrated in April to July each year, and the epidemic cycle was 2 years; most of the cases were 1 to 3-year old children, with more cases in male. The incidence density varied across the region, with the highest density observed in Ninghai (4 524.76/100 000 person-years), followed by Xiangshan (3 984.22/100 000 person-years). In 3 748 library-conformed cases, 2 834(75.61%) were detected positive, among which enterovirus-A71, Cox-A16 and other enteroviruses accounted for 9.03%, 31.55% and 59.42%, respectively. During the study period, the cumulative coverage of enterovirus-A71 vaccine increased year by year, with the proportion of enterovirus-A71 and severe cases both gradually decreasing. CONCLUSION The current status of hand, foot and mouth disease in Ningbo is still serious. Children under 3-year old (especially male children aged 1 year) were the key population for prevention and control. Vaccination might lead to changes in major pathogenic virus type, of which more attention should be paid to the potential impact on disease surveillance, prevention and control.
Child ; Child, Preschool ; China/epidemiology* ; Enterovirus ; Enterovirus Infections ; Hand, Foot and Mouth Disease/epidemiology* ; Humans ; Incidence ; Infant ; Male ; Retrospective Studies

Animals ; China ; epidemiology ; Enterovirus A, Human ; genetics ; physiology ; Enterovirus Infections ; epidemiology ; metabolism ; virology ; Humans ; Receptors, Virus ; genetics ; metabolism

In order to explore the genotype distribution and molecular evolution of non-polio enterovirus (NPEVs)in Yunnan Province,the People's Republic of China, we sequenced and analyzed the partial VP1 coding region of 105 NPEVs isolated from acute flaccid paralysis (AFP) surveillance in Yunnan province during a 5- year study period from 2006 to 2010. The viral genomes of 105 NPEVs were translated to corresponding amino acid sequences and compared with those of the prototype strains, and the phylogenetic tree was constructed among these VP1 nucleotide sequences and other prototype strains from GenBank. Analysis showed that 18 isolates were classified into 7 serotypes of human enterovirus A species, while 77 isolates into 22 serotypes of B and 10 isolates into 4 serotypes of C species. However, we did not isolate any viruses which belonged to human enterovirus D species. Thus, under AFP surveillance, human enterovirus B species accounted for 73. 3% of the 105 isolates and was considered as the predominant one,followed by human enterovirus A(17. 1%) and human enterovirus C(9. 5%). Phylogenetic analysis showed that various serotypes of the virus and the corresponding prototype strains or other representative strains clustered into the same grooup, however, Yunnan strains and prototype strains were located in the different branches (except CA2,EV90 and EV76). The degree of variation was different even among the same genotype strains. This report showed that different genotype strains spread widely in Yunnan Province.
China ; epidemiology ; Enterovirus ; classification ; genetics ; isolation & purification ; Enterovirus Infections ; epidemiology ; virology ; Humans ; Molecular Sequence Data ; Molecular Typing ; Phylogeny

This research firstly reported the molecular analysis of ECHO25 (Entric Cytopathic Human Orphanviruses Type 25). To clarify molecular characteristics of the ECHO25 virus isolates in Henan Province and its relationship with the rest of world's isolates,the complete VP1 sequences of the 4 isolates in Henan were successfully amplified by RT-PCR and were compared with other ECHO25 isolates available from GenBank. Compared with the prototype strain JV-4, the nucleotide sequence identity was 79.2%-80.1%, and the amino sequence identity was 89.0%-92.4, the nucleotide sequence identity among the 4 strains isolates in Henan Province was 93.0%-99.0%, the amino sequence identity was 92.4%-97.5%. HN-01 and HN-26 strains had the highest level of homology, the nucleotide homology was 99.0%; All the 4 strains belonged to the B1 genotype.
China ; epidemiology ; Enterovirus B, Human ; classification ; genetics ; isolation & purification ; Enterovirus Infections ; epidemiology ; virology ; Humans ; Molecular Sequence Data ; Phylogeny

This report presents an overview of human enterovirus B species in Henan Province. A total of 14 isolates of HEV-B species isolated under HFMD surveillance network during the six months in 2010 were examined. Based on molecular typing results targeting VP1 region, 14 isolates were classified into 6 serotypes of HEV-B. Furthermore, comparison of these 14 isolates with reference strains and strains in mainland China was conducted. The phylogenetic analysis revealed that E25, E11 and E6 showed homology with those from Shandong Province which adjoins Henan Province. E1 and E13 showed homology with those from Yunnan Province, and E30 showed homology with Henan strain isolated in 2008. Cocirculation of two lineages of echovirus 6 was observed.
China ; epidemiology ; Enterovirus B, Human ; classification ; genetics ; isolation & purification ; Enterovirus Infections ; epidemiology ; virology ; Feces ; virology ; Humans ; Molecular Sequence Data ; Phylogeny

OBJECTIVETo analyze the dynamic pattern and the distributive characteristics of neutralizing antibody against enterovirus 71 (EV-A71 ) in children aged 6-35 months in Jiangsu province from 2012 to 2014.

METHODSFrom March, 2012 to March, 2014, a total of 1 276 children aged between 6 and 35 months were regularly followed up on day 0, year 1 and year 2 for EV-A71 neutralizing antibody test based on the enterovirus surveillance system, with the method of reporting by their guardian or being visited in Ganyu Sheyang Taixing Donghai Pizhou and Baoying in Jiangsu province. At the same time, samples were taken from the suspected persons infected by enterovirus. The χ(2) test or variance analysis was used to compare the difference of the positive rates and the geometric mean titer(GMT) of EV-A71 neutralizing antibody in different subjects.

RESULTSIn 2 years follow-up, the positive rates of EV-A71 antibody increased as the growth of the age,and the positive rates on day 0, year 1 and year 2 were 22.57% (288/1 276), 37.72%(444/1 177) and 42.84%(422/985), respectively (χ(2) values were 39.33, 56.41, 32.25; P< 0.001).The GMTs were 9.95, 15.37 and 24.05, respectively (F values were 22.90,46.36,41.58;P<0.001). In 2 years, the annually new infection rates were 13.47%(158/1 173) and 20.73%(192/926),respectively, and the annually decay rates of EV-A71 antibody were 2.81%(33/1 173) and 8.10%(75/926).

CONCLUSIONSIn 2012 to 2014, the positive rates and the GMTs of EV-A71 antibody of children increased as the growth of the age in Jiangsu. The higher annually new infection rate was in children aged 3 to 4 years. The EV-A71 neutralizing antibody level could maintain at least two years after natural infection.

Antibodies, Neutralizing ; blood ; Antibodies, Viral ; blood ; Child, Preschool ; China ; epidemiology ; Enterovirus A, Human ; Enterovirus Infections ; blood ; Humans ; Infant ; Seroepidemiologic Studies