BACKGROUND: Severe hand-foot-and-mouth disease (HFMD) is a life-threatening contagious disease among young children and infants. Although enterovirus A71 has been well acknowledged to be the dominant cause of severe HFMD, there still remain other unidentified risk factors for severe HFMD. Previous studies mainly focused on identifying the individual-level risk factors from a clinical perspective, while rare studies aimed to clarify the association between regional-level risk factors and severe HFMD, which may be more important from a public health perspective. METHODS: We retrieved the clinical HFMD counts between 2008 and 2014 from the Chinese Center for Disease Control and Prevention, which were used to calculated the case-severity rate in 143 prefectural-level cities in mainland China. For each of those 143 cities, we further obtained city-specific characteristics from the China City Statistical Yearbook (social and economic variables) and the national meteorological monitoring system (meteorological variables). A Poisson regression model was then used to estimate the associations between city-specific characteristics (reduced by the principal component analysis to avoid multicollinearity) and the case-severity rate of HFMD. The above analysis was further stratified by age and gender to examine potential modifying effects and vulnerable sub-populations. RESULTS: We found that the case-severity rate of HFMD varied dramatically between cities, ranging from 0 to 8.09%. Cities with high case-severity rates were mainly clustered in Central China. By relating the case-severity rate to city-specific characteristics, we found that both the principal component characterized by a high level of social and economic development (RR = 0.823, 95%CI 0.739, 0.916) and another that characterized by warm and humid climate (RR = 0.771, 95%CI 0.619, 0.960) were negatively associated with the case-severity rate of HFMD. These estimations were consistent across age and gender sub-populations. CONCLUSION Except for the type of infected pathogen, the case-severity rate of HFMD was closely related to city development and meteorological factor. These findings suggest that social and environmental factors may also play an important role in the progress of severe HFMD.
Adolescent ; Child ; Child, Preschool ; China/epidemiology* ; Cities/epidemiology* ; Female ; Hand, Foot and Mouth Disease/virology* ; Humans ; Incidence ; Infant ; Infant, Newborn ; Male ; Risk Factors

Objective: To estimate the serotype and age-specific hospitalization burden associated with hand, foot and mouth disease (HFMD) in Anhua county of Hunan province, between October 2013 and September 2016. Methods: We collected hospitalization records of HFMD patients from 6 virological surveillance hospitals, and reimbursement records through new rural cooperative medical system from 23 township health centers to estimate the age-specific hospitalization burden of HFMD in Anhua. Combined with the results of virological surveillance, the serotype-specific hospitalization burden of HFMD in Anhua, was estimated. Results: During the three years, it was estimated that 3 541 clinical diagnosed HFMD cases, including 3 146 laboratory-confirmed HFMD cases, were hospitalized in Anhua, but only one was diaguosed as being severe. The estimated average hospitalization rate was 723/100 000(95%CI: 699/100 000-747/100 000) for clinical diagnosed HFMD and 642/100 000 (95%CI: 620/100 000-665/100 000) for laboratory-confirmed HFMD between October 2013 and September 2016. The cases caused by Cox A16 (208/100 000) and Cox A6 (202/100 000) had higher hospitalization rates compared with the cases caused by EV71 (130/100 000), Cox A10 (38/100 000) and other enterovirus (64/100 000), and the difference was statistically significant (P<0.001). HFMD-associated hospitalization rates peaked in children aged 1 year (3 845/100 000), and then decreased with age. Compared with the hospitalized HFMD caused by EV71 and Cox A16, Cox A6-associated hospitalizations mainly occurred in younger age groups (P<0.001). Conclusion: Our study revealed a substantial hospitalization burden associated with mild HFMD caused by EV71, Cox A16, Cox A6 and Cox A10, especially in young children, in Anhua.
Child ; China/epidemiology* ; Enterovirus ; Enterovirus A, Human/isolation & purification* ; Enterovirus Infections/virology* ; Hand, Foot and Mouth Disease/virology* ; Hospitalization/statistics & numerical data* ; Hospitals/statistics & numerical data* ; Humans ; Infant ; Serogroup

OBJECTIVETo investigate the etiology of severe hand-foot-mouth disease (HFMD) in children in Henan province.

METHODSA total of 244 HFMD cases admitted to a hospital in Zhengzhou from April to June of 2014 were recruited for research sampling, Real-time RT-PCR, virus isolation, VP1 sequencing and alignment methods were used to test the enterovirus-related etiology. SPSS 17.0 was used in performing statistical analysis.

RESULTSThere were 109 severe and 135 mild cases among all the 244 HFMD cases. The number of enterovirus positive stool samples was 229, with positive rate as 93.85%. EV71, Cox A16 and Cox A10 made up 83.84%, 5.68% and 8.30% of the enterovirus etiologicy, strains, respectively. EV71 infection caused 8 HFMD cases with heart-lung failure and 2 death, Cox A10 infection led to 1 HFMD case with heart-lung failure and death. There were statistically differences seen regarding the enterovirus infection rates between severe and the mild HFMD cases (χ(2)=5.312,P=0.021). Statistically significant difference was seen in the constituent ratio of EV71, Cox A16 and the others by Fisher' s exact test (P=0.048). There was statistically significant difference seen between the cardiorespiratory failure rate and the fatality rate by EV71 and Cox A10 infection (χ(2)=0.051,P=0.821; χ(2)=2.198,P=0.138). Cox A10 strains idenfied in Henan in 2014 belonged to genotype 6. The rates on homology of nucleotide and amino acid among the Cox A10 strains in Henan in 2014 were 94.3%-99.7% and 96.3%-100.0% respectively.

CONCLUSIONSEV71 still remained the most common pathogen that causing severe HFMD in children, with the increasing Cox A10 percentage in the pathogens spectrum of HFMD infection. Cox A10 strains in Henan in 2014 belonged to genotype 6. Genotype 6 Cox A10 had appeared and widely distributed in Henan for long time, but not yet variated or reconstructed. Cox A10 infection could lead to cardio-respiratory failure thus called for the monitoring program on non-EV71 and non-Cox A16 enterovirus, especially Cox A10 to be strenthened.

Amino Acids ; genetics ; Biometry ; Child ; Enterovirus A, Human ; classification ; genetics ; isolation & purification ; Enterovirus Infections ; epidemiology ; virology ; Evolution, Molecular ; Genotype ; Hand, Foot and Mouth Disease ; epidemiology ; prevention & control ; virology ; Hospitals ; statistics & numerical data ; Humans ; Real-Time Polymerase Chain Reaction

OBJECTIVETo study the molecular epidemiology of hand-foot-mounth disease (HFMD) associated Coxsackievirus A10 (Cox A10) identified in Fujian province.

METHODSA total of 1 525 specimens from non-EV71 non-Cox A16 HFMD patients were collected during 2011-2014. Isolated virus strains were identified and sub-typed. Full-length coding regions for the VP1 gene of the predominant serotype Cox A10 isolates were amplified and sequenced.

RESULTSAmong the 407 non-EV71 non-Cox A16 HFMD cases confirmed by virus isolation and molecular subtyping, 103 (25.3%) were caused by Cox A10, accounting for 11.0%, 6.0%, 18.4% and 9.2% among the HFMD-associated entero-viruses identified in 2011, 2012, 2013 and 2014, respectively, in Fujian province. Compared to the general features observed in the HFMD epidemics, no differences on the Cox A10-specificity rates were observed among factors as geographical origins, gender or age groups, but all with high rates of severity. Data from the nucleotide sequence analyses on VP1 genes showed low homology levels of 76.0%-77.1% among Cox A10 strains from Fujian province, in contrast to the prototype Cox A10 strain, but with high levels of homology in the amino acid sequences (91.9%-93.6%). RESULTS from the Phylogenetic analysis also indicated that Cox A10 isolates from Fujian province were distinct from the prototype strain or other isolates from other countries but was homologous to domestic strains, but the Fujian isolates clustered into multiple branches.

CONCLUSIONSCox A10 remained one of the predominant serotypes of HFMD in Fujian province. Cox A10 isolates identified in Fujian province were co-circulating and co-evolving with other domestic strains.

Benzeneacetamides ; Child ; Child, Preschool ; China ; epidemiology ; Enterovirus A, Human ; classification ; genetics ; isolation & purification ; Epidemics ; Female ; Hand, Foot and Mouth Disease ; epidemiology ; genetics ; virology ; Humans ; Infant ; Male ; Molecular Epidemiology ; Molecular Sequence Data ; Open Reading Frames ; Phylogeny ; Piperidones ; Serogroup

OBJECTIVETo analyze the genotype, epidemic pattern and the characteristics of the disease of enteroviruses during the epidemic season of hand, foot and mouth disease (HMFD) in children from 2013 to 2014 in Beijing to provide the scientific evidence for prevention and treatment of HFMD.

METHODDuring April to September in 2013 and March to October in 2014, a total of 977 throat swabs were collected from children who visited the Children's Hospital Affiliated to Capital Institute of Pediatrics, including 147 from patients with HFMD in 2013, 343 with HFMD, 201 with atypical HFMD, 83 with herpangina, 25 with fever with convulsions, 64 fever with rash and 114 with rash in 2014. Enteroviruses universal type (EV), Enteroviruses type 71 (EV71) and Coxsackievirus group A 16 (CA16) were detected by real-time RT-PCR respectively. The nucleic acid of specimens which were identified with non-EV71, non-CA16 was tested by nested PCR and analyzed by VP1 sequencing. The detection rate and epidemic pattern of different genotypes of enterovirus were analyzed among different age groups and between 2013 and 2014.

RESULTOf 977 throat swabs, 80. 1% samples were detected positive for enteroviruses. The positive rates of CA16, EV71, CA6, CA10, CA4 and other EVs were 25. 6% (250/977), 18. 9% (185/977), 20. 0% (195/977), 5. 0% (49/977), 1.5% (15/977) and 9.1% (89/977), respectively. Twenty six of the 89 other EVs included CA2, CA5, CA8, CA9, CA12, CA14, CB2, CB5, E6, E9 and E25, each genotype of which was no more than 3. The nucleotide homologies shared among CA6, CA10 and CA4 strains between 2013 and 2014 were 94. 3% - 100%, 93. 8% - 99. 1% and 92.7% - 99. 8%, respectively. The positive rates of ≤1 year group were 71. 1% (106/149), which was lower than that of other age groups (all P <0. 05), but similar to that of >5 year group (χ2 =1. 181,P = 0. 277). In 2013, the positive rate of EV was 85. 7% (126/147) and the predominant genotype was CA6 54. 8% (69/126), followed by CA16 20. 6% (26/126) and EV71 11. 9% (15/126). In 2014, the positive rate of EV was 85. 4% (293/343) in the 343 children with HFMD, the predominant genotypes were CA16 with the positive rate of 42. 7% (125/293), EV71 with 38. 2% (112/293) and CA6 with only 11. 3% (33/293). In 2014, the positive rates of EV in 201 atypical HFMD, 83 herpangina, 25 fever with convulsions, 64 fever with rash and 114 rash were 83. 6% (168/201), 80. 7% (67/83), 76. 0% (19/25), 64. 1% (41/64) and 60. 5% (69/114), respectively. All genotypes of enteroviruses peaked mainly during May to August every year, but there were no obvious epidemiological pattern about each genotype.

CONCLUSIONCA6 became the main causative agent of HFMD in 2013, however, CA16 and EV71 predominated again in 2014 in Beijing. The clinical manifestations caused by CA6, CA10, CA4 and other genotype of enteroviruses differed from EV71 and CA16. Besides EV71 and CA16, more attention should be paid to CA6, CA10, CA4 and other type of enteroviruses.

Beijing ; epidemiology ; Child, Preschool ; Enterovirus A, Human ; classification ; Enterovirus Infections ; epidemiology ; virology ; Exanthema ; Fever ; Genotype ; Hand, Foot and Mouth Disease ; epidemiology ; virology ; Humans ; Infant ; Real-Time Polymerase Chain Reaction

Hand, foot, and mouth disease (HFMD) is a viral infectious disease regarded to be a public-health problem worldwide. Since the 1990s, HFMD began to spread in the Asia-Pacific region (especially in South-East Asia). HFMD outbreaks have occurred in mainland China frequently since 2008, and the morbidity and mortality of HFMD has continued to increase in recent years. In mainland China, enterovirus A serotype enterovirus A71 (EV-A71) and coxsackievirus A16 (CVA16) have been the major pathogens of HFMD during these years. However, the etiological spectrum of HFMD changes with time. This review focuses mainly on the etiological spectrum of HFMD and changes in epidemic patterns in mainland China.
China ; epidemiology ; Disease Outbreaks ; Enterovirus ; classification ; genetics ; isolation & purification ; Hand, Foot and Mouth Disease ; epidemiology ; virology ; Humans ; Prevalence

OBJECTIVETo understand the infection status of enterovirus 71 (EV71) and coxsackievirus A16 (Cox A16) among children receiving health examination for child care setting entrance in Beijing and their related medical care seeking practice and provide evidence for the estimation of disease burden caused by hand foot and mouth disease (HFMD).

METHODSSerological survey was conducted in the local children receiving health examination for child care setting entrance. Enzyme-linked immunosorbent assay (ELISA) was conducted to detect anti-EV71 and anti-Cox A16 IgG and IgM.

RESULTSA total of 813 children were surveyed (mean age: 3.5 ± 1.0 year old). The seropositive rate was 61.9% and 4.4% for anti-Cox A16 IgG and IgM. The seropositive rate was 9.3% and 1.1% for anti-EV71 IgG and IgM. No significant difference was observed in sex specific seropositive rate (P > 0.05). However, significant differences were found in seropositive rate among different age groups (P < 0.05). Among the children who were anti-Cox A16 positive, 7.8% had ever had rashes on their hands and feet, mouth or buttocks (HFMD-like rashes). Among the children who were anti-EV71 positive, 10.7% had ever had HFMD-like rashes. For the children who were anti-Cox A16 or anti-EV71 positive, only 7.1% were brought to see doctors by their parents. However, among the seropositive children with rashes, 80.5% were brought to see doctors.

CONCLUSIONIn the healthy children at the age to go to child care setting in Beijing, most had ever infected with Cox A16. The anti-EV71 positive rate was much lower than the anti-Cox A16 positive rate. It was necessary to strengthen the prevention and control of EV71 infection in child cares settings.

Antibodies, Anti-Idiotypic ; blood ; Beijing ; epidemiology ; Child Health Services ; utilization ; Child, Preschool ; Cost of Illness ; Enterovirus A, Human ; isolation & purification ; Enzyme-Linked Immunosorbent Assay ; Female ; Hand, Foot and Mouth Disease ; epidemiology ; virology ; Humans ; Male ; Parents ; psychology ; Patient Acceptance of Health Care ; statistics & numerical data

To investigate the epidemiology of hand, foot, and mouth disease (HFMD) and the genetic characteristics of enterovirus A71 (EV-A71) in Linyi of Shandong Province, China during 2007-2012. The number of reported HFMD cases were obtained from the National Notifiable Disease Reporting System (NNDRS) were analyzed by descriptive epidemiology method; the VP1 region of EV-A71 isolated from HFMD patients in Linyi was amplified and sequenced. Finally, the genetic variability and phylogenecity of VP1 sequences of EV-A71 were analyzed by MEGA 5.0. The results showed that HFMD incidence was reported in each year from 2007 to 2012 in Linyi, and the highest incidence and mortality were reported in 2009, when there were total 14697 cases and 9 of death. The reported incidence was 140.28/100000, and the mortality was 0.086/100000. The peak incidence usually occurred between April and July, and the summit occurred in May. Scattered children accounted for 77.37%-92.00% of all cases. The peak age was 2.5 years during 2007-2009 and 1.5 years during 2010-2012. A total of 1365 laboratory-confirmed HFMD cases were reported in the 6 consecutive years, accounting for 2.98% of the gross number. Among these reports, the ratio of EV-A71 was 44.18%, and the ratio of coxsackievirus A16 (CVA16) was 46.59%. All EV-A71 strains isolated in Linyi during 2007-2012 belonged to the C4a evolutionary branch of C4 genotype. In conclusion, HFMD outbreaks occurred every year in Linyi during 2007-2012. Incidence varied significantly among different counties. The peak incidence in each year lasted from April to July. Most of the patients were children under 3 years of age, and scattered children took the highest proportion. Co-circulation of EV-A71 and CVA16 was the major cause of HFMD in each year. Since the first report of HFMD prevalence caused by EV-A71 (C4a) in 2007, the virus has been prevalent continuously in Linyi for 6 years.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Child ; Child, Preschool ; China ; epidemiology ; Enterovirus ; classification ; genetics ; isolation & purification ; Female ; Hand, Foot and Mouth Disease ; epidemiology ; virology ; Humans ; Infant ; Male ; Middle Aged ; Molecular Sequence Data ; Phylogeny ; Young Adult

This study aims to analyze the epidemiological features and pathogenic characteristics of hand, foot and mouth disease (HFMD) in Gansu Province, China and to provide a basis for the development of effective prevention and control measures. The descriptive epidemiological analysis was used to analyse the data of HFMD cases in Gansu. The specimens collected from hospitals were subjected to RT-PCR or real-time PCR to detect human enterovirus (HEV) nucleic acid, and HEV strains were isolated using human rhabdomyosarcoma cells and human laryngeal carcinoma cells. The complete VP1-encoding region of several identified enterovirus A71 (EV71) and coxsackievirus A16 (CVA16) was subjected to full-length amplification by RT-PCR and then to sequencing and analysis. A total of 52 550 HFMD cases were reported in Gansu from 2008 to 2012, including 205 severe cases and 27 deaths. The incidence rates in the whole province from 2008 to 2012 were 22.42/10(5), 49.29/10(5), 47.20/10(5), 27.27/10(5), and 55.84/10(5), respectively. There were cases in all the 14 cities or prefectures in Gansu, and Lanzhou had the largest number of cases (16 001 cases), accounting for 30.45% of all cases in the province. HFMD cases were mostly reported during May to July, accounting for 51.69% of all cases throughout the year. The male-to-female ratio was 1.69:1. Of all the cases, 87.59% were under the age of five. Of the 5 416 cases for laboratory tests, 3 322 (61.34%) were positive for HEV nucleic acid, including EV71 (46.96%), CVA16 (41.57%), and other HEVs (11.47%). Among the 186 severe cases, 114 (61.29%) were positive for HEV nucleic acid, and 82.46% of the positive cases for EV71. All the 25 dead cases were infected with EV71. A total of 402 strains were isolated from 3 111 specimens collected from hospitals (2 123 throat swab specimens, 705 stool specimens, and 705 herpes specimens), including EV71 (70.15%), CVA16 (27.11), other coxsackievirus A (3.98%), coxsackievirus B (2.49%), echovirus (1.74%), and adenovirus (1.99%). The genotyping of VP1- encoding region showed that all the 194 EV71 strains isolated during 2008-2012 belonged to the C4a evolutionary branch of C4 subtype; among the 45 CVA16 strains, 12 belonged to the Bla evolutionary branch of B1 subtype and 33 to the B1b evolutionary branch, and B1b became the predominant subtype in 2012. In conclusion, in Gansu Province, HFMD occurs mostly in children under the age of five; EV71 and CVA16 are the main pathogens of this disease, and the two are predominant alternately from 2008 to 2012; the severe and dead cases of HFMD are closely related to infection with EV71; the types of pathogens varied across different regions in the same year during 2008-2012.
Adolescent ; Child ; Child, Preschool ; China ; epidemiology ; Cluster Analysis ; Enterovirus ; pathogenicity ; physiology ; Evolution, Molecular ; Female ; Hand, Foot and Mouth Disease ; epidemiology ; virology ; Humans ; Infant ; Infant, Newborn ; Male ; Young Adult

The aim of this study was to understand the enterovirus types and biological features of pediatric cases of HFMD in Sanmenxia City during 2011, and compare the latter to a cohort of healthy children. Stool samples of 55 cases of HFMD and 60 healthy children were collected for the isolation and identification of enteroviruses using RNA extraction and real-time RT-PCR assays. EV71 and CA16 were identified by nucleotide sequencing using virus-specific VP1 primers; for the other enteroviruses, 012/011 and 008/013 primers were used for amplification and sequencing. The results were analysed by sequence alignment with known sequences, and the characteristics of the EV71 VP1 gene were also analyzed. The detection rates for enteroviruses in cases of HFMD and healthy children were 52.73% (29/55) and 18.33% (11/60), respectively. Among these, there were 22 cases of EV71, four cases of CA16 and three cases of other enteroviruses in the cases with HFMD. Eleven healthy children had intestinal viruses, of which nine were Coxsackie B virus strains (81.82%, 9/11). Gene sequencing of the 19 EV71 strains illustrated that they were all subgenotype C4a, but the evolutionary tree showed an obvious clustering between cases from Lingbao City and Lushi County. This study demonstrates that the EV71 subgenotype C4a and CA16 strains were the most common cause of HFMD in Sanmenxia City in 2011, and that Coxsackie B strains were prevalent in healthy children. This finding may indicate that there is a widespread source of recessive infection in the community.
Child ; Child, Preschool ; China ; epidemiology ; Cities ; epidemiology ; Enterovirus A, Human ; classification ; genetics ; isolation & purification ; Female ; Hand, Foot and Mouth Disease ; epidemiology ; virology ; Humans ; Infant ; Male ; Phylogeny ; Viral Proteins ; genetics