Study on Thin Lamination of Carbon Fiber Based on Mechanical Broadening.

Carbon fiber has excellent mechanical properties and plays an important role in modern industry. However, due to the complexity of the carbon fiber widening process, the industrial application of carbon fiber is limited. By designing the carbon fiber widening equipment of automaton, the relationship between the widening width of carbon fiber and the process parameters is studied, and the optimum developing process parameters are obtained, to improve the performance of carbon fiber composites to a certain extent. In this study, the widening process of carbon fiber was studied based on the mechanical broadening method. Firstly, an automatic broadening equipment was designed, and the effects of the initial tension, the number of straight rods, the number of convex rods, and the drawing speed on the widened width during the broadening process were discussed. The widening effect was evaluated by SEM imaging and mechanical testing. At the same time, the factors affecting the broadening width and broadening defects during the broadening process were analyzed, and the optimal broadening process parameters were obtained. The results showed that within a specific range, a higher initial tension, a greater number of convex rods, and an appropriate speed resulted in relatively smaller damage to the broadening of carbon fibers. Through the design of automatic broadening, this experiment explores optimal broadening process parameters, provides a reference for the improvement of the carbon fiber broadening process and further promotes large-scale industrial applications of carbon fiber.

Changes in peripheral blood cytokines in patients with severe fever with thrombocytopenia syndrome.

Severe fever with thrombocytopenia syndrome (SFTS) is recognized as an emerging infectious disease. This study aimed to investigate the pathogenic mechanism of SFTS. A total of 100 subjects were randomly included in the study. Cytokine levels were detected by enzyme-linked immunosorbent assay and the viral load was detected by micro drop digital PCR. The results showed that levels of interleukin-6 (IL-6), IL-8, IL-10, IFN-inducible protein-10 (IP-10), monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory protein-1α (MIP-1α), transforming growth factor-ß1 (TGF-ß1), and regulated upon activation normal T cell expressed and secreted factor (RANTES) differed significantly among the SFTS patient group, healthy people group, and asymptomatic infection group (p < .05). Compared to the healthy people group, the patient group had increased cytokine levels (IL-6, IL-10, IP-10, MCP-1, and IFN-γ) but reduced levels of IL-8, TGF-ß1, and RANTES (p < .0167). IL-6, IL-8, IL-10, IP-10, MCP-1, MIP-1α, TGF-ß1, and the RANTES levels had different trends after the onset of the disease. IL-6, IL-10, IP-10, and MCP-1 levels in severe patients were higher than those in mild patients (p < .05). There was a positive correlation between viral load and IL-6 and IP-10 but a negative correlation between viral load and RANTES. SFTSV could cause a cytokine change: the cytokine levels of patients had different degrees of fluctuation after the onset of the disease. The levels of IL-6 and IL-8 in the asymptomatic infection group were found between the SFTS patients group and the healthy people group. The levels of IL-6, IL-10, IP-10, and MCP-1 in the serum could reflect the severity of the disease, and the levels of IL-6, IP-10, and RANTES were correlated with the viral load.

Severe fever with thrombocytopenia syndrome: a systematic review and meta-analysis of epidemiology, clinical signs, routine laboratory diagnosis, risk factors, and outcomes.

BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease with the high case-fatality rate, and lack of vaccines. We aimed to systematically analysed the epidemiological characteristics, clinical signs, routine laboratory diagnosis, risk factors, and outcomes. METHODS: Documents on SFTS were collected by searching the Chinese National Knowledge Infrastructure, Wan Fang Data, PubMed, Embase, and Web of Science databases from 2011 to 2018. Meta-analysis was performed by using Review Manager and Stata software. RESULTS: Twenty-five articles involving 4143 cases were included. Diarrhea (odds ratio (OR) =1.60, 95% confidence interval (CI): 1.06 to 2.42, P = 0.02), and vomiting (OR = 1.56, 95% CI: 1.01 to 2.39, P = 0.04) on admission were associated with the fatal outcomes of SFTS. Compared to patients with mild symptoms, patients with severe symptoms had significantly elevated levels of lactic acid dehydrogenase (standard mean difference (SMD) =1.27, 95% CI: 0.59 to 1.94), alanine aminotransferase (SMD = 0.55, 95% CI: 0.24 to 0.85), aspirate aminotransferase (SMD = 1.01, 95% CI: 0.69 to 1.32), and creatine kinase (SMD = 1.04, 95% CI: 0.74 to 1.33) but had reduced platelet counts (SMD = -0.87, 95% CI: - 1.16 to - 0.58) and albumin levels (SMD = -1.00, 95% CI: - 1.32 to - 0.68). The risk factors for poor prognosis included age (mean difference (MD) =6.88, 95% CI: 5.41 to 8.35) and farming (OR = 2.01, 95% CI: 1.06 to 3.80). For the risk factors of contracting SFTS, the incidence of SFTS related to tick bites was 24% [95% CI: 0.18 to 0.31]. The pooled case-fatality rate of SFTS patients was 18% [95% CI: 0.16 to 0.21]. CONCLUSIONS: China is the country with the highest incidence of SFTS. May to July was the peak of the epidemic, and farmers were a high-risk group. The risk factor for SFTS included age (poor prognosis) and tick bites (contracting SFTS). Patients with severe diarrhea and vomiting symptoms on admission should be noted. Clinicians could use routine laboratory parameters and clinical symptoms as references for clinically suspected cases, classification of SFTS, and timely treatment, especially in basic hospitals.

Mass spectrometry-based Shiga toxin identification: A clinical validation.

After we published our preliminary study on the use of liquid chromatography-tandem mass spectrometry (LC-MS/MS) and curated E. coli toxin databases on the identification of E. coli Shiga toxins (Stxs) in the Journal of Proteomics in year 2018, we were encouraged to further refine the method and test clinical isolates. In this study, different concentrations of mitomycin C (MMC) and ciprofloxacin (CF), two common antibiotic/chemotherapy agents capable of stimulating Stx production, were first tested and compared on three reference strains and eight clinical isolates to observe the toxin induction and subsequent identification. Notably, no differences were observed between the two agents other than the concentrations applied. Seventeen more clinical isolates were then tested using fixed MMC and CF concentrations and sample amount. This study confirms that the majority of stx2-positive E. coli strains can be stimulated to produce sufficient toxin for confident identification. This does not occur with stx1-positive E. coli isolates, however, despite the fact that both Stxs can be identified for several isolates without MMC or CF stimulation. BIOLOGICAL SIGNIFICANCE: Stxs, especially Stx2, are very important causes of severe food-borne disease, even death. This study confirms that receptor analogue-based affinity enrichment of Stxs, after MMC or CF treatment of E. coli, is useful for fast and accurate Stx2 identification through LC-MS/MS.

Mass spectrometry-based Shiga toxin identification: An optimized approach.

Toxin expression is a key factor in Shiga toxin (Stx)-producing E. coli, a common pathogen involved in foodborne disease outbreaks. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) based approach has been used in this study to identify commonly reported E. coli toxins, with a focus on Shiga toxins (Stxs). Different sample preparation methods using variable culture conditions and concentrations of mitomycin C (MMC), a common antibiotic/chemotherapy agent capable of stimulating Stx production, were first tested on reference strains EDL933 and 90-2380 by LC-MS/MS detection of tryptic digests of receptor-analogue affinity binding enriched Stx preparations from culture supernatants and lysates. A curated E. coli protein toxin database was also used for faster and more straightforward toxin identification. With eight more genetically confirmed E. coli strains examined to verify the method, this preliminary study indicates that receptor-analogue based affinity enrichment on cell lysate or supernatant is a sensitive and accurate method for Stx identification. BIOLOGICAL SIGNIFICANCE: The existence of Stx is very important for identifying Stx-producing E. coli and implementing a clinical treatment regime. This study demonstrates for the first time that using a curated E. coli toxin database, together with receptor-analogue-based affinity enrichment of Stxs after MMC treatment of E. coli, is an easy and appropriate approach for fast and accurate Stx identification through LC-MS/MS.

Bites from the same dog, different outcomes for two patients: a case report.

BACKGROUND: Rabies is a serious reemerging zoonosis in China. At present human rabies cases are primarily diagnosed based on clinical presentation. CASE PRESENTATION: In August 2012, a woman and her son were attacked by a stray dog in Henan, China. The son received rabies postexposure prophylaxis (wound treatment followed by vaccine, no immunoglobulin), however, the mother did not. Rabies infection was subsequently laboratory confirmed in the mother and she died in December; her son is alive and healthy after 2 years of follow-up. CONCLUSION: This report documents that the timely utilization of postexposure prophylaxis is a required measure in preventing rabies after exposure to an animal bite.

Application and Comparison of Laboratory Parameters for Forecasting Severe Hand-Foot-Mouth Disease Using Logistic Regression, Discriminant Analysis and Decision Tree.

BACKGROUND: In recent years, the prevalence of hand-foot-mouth disease (HFMD) in China and some other countries has caused worldwide concern. Mild cases tend to recover within a week, while severe cases may progress rapidly and tend to have bad outcome. Since there is no vaccine for HFMD and anti-inflammatory treatment is not ideal. In this study, we aimed to establish a valid forecasting model for severe HFMD using common laboratory parameters. METHODS: Retrospectively, 77 severe HFMD cases from Zhengzhou Children's hospital in the peaking period between years 2013 to 2015 were collected, with 77 mild HFMD cases in the same area. The study recorded common laboratory parameters to assist in establishment of the severe HFMD model. After screening the important variables using Mann-Whitney U test, the study also matched the logistic regression (LR), discriminant analysis (DA), and decision tree (DT) to make a comparison. RESULTS: Compared with that of the mild group, serum levels of WBC, PLT, PCT, MCV, MCH, LCR, SCR, LCC, GLO, CK-MB, K, S100, and B in the severe group were higher (p < 0.05), while MCR, EOR, BASOR, SCC, MCC, EO, BASO, NA, CL, T, Th, and Th/Ts were lower (p < 0.05). Five indicators including MCR, LCC, Th, CK-MB, and CL were screened out by LR and the same for DA, and five variables including EO, LCC, CL, GLO, and MCC screened out by DT. The area under the curve (AUC) of LR, DA, and DT was 0.805, 0.779 and 0.864, respectively. CONCLUSIONS: The findings were that common laboratory indexes were effectively used to distinguish the mild HFMD cases and severe HFMD cases by LR, DA, and DT, and DT had the best classification effect with an AUC of 0.864.

[Etiology study on severe cases caused by hand-foot-mouth disease in children from Henan province, 2014].

OBJECTIVE: To investigate the etiology of severe hand-foot-mouth disease (HFMD) in children in Henan province. METHODS: A 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. RESULTS: There 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. CONCLUSIONS: EV71 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.

Epidemiological and etiological characteristics of hand, foot, and mouth disease in Henan, China, 2008-2013.

Hand, foot, and mouth disease (HFMD) is a common childhood illness caused by enteroviruses. HFMD outbreaks and reported cases have sharply increased in China since 2008. Epidemiological and clinical data of HFMD cases reported in Henan Province were collected from 2008 to 2013. Clinical specimens were obtained from a subset of these cases. Descriptive epidemiological methods were used to analyze the time, region and population distribution. The VP1 gene from EV71 and CA16 isolates was amplified, and the sequences were analyzed. 400,264 cases of HFMD were reported in this study, including 22,309 severe and 141 fatal cases. Incidence peaked between April and May. Laboratory confirmation was obtained for 27,692 (6.9%) cases; EV71, CA16, and other enteroviruses accounted for 59.5%, 14.1%, 26.4%, respectively. Phylogenetic analysis revealed that EV71 belonged to the C4a evolution branch of C4 sub-genotype and CA16 belonged to subtype B1a or B1b. The occurrence of HFMD in Henan was closely related to season, age and region distribution. Children under five were the most affected population. The major pathogens causing HFMD and their genotypes have not notably changed in Henan. The data strongly support the importance of EV71 vaccination in a high population density area such as Henan, China.

[Expression and activity determination of recombinant capsid protein VP2 gene of enterovirus type 71].

OBJECTIVE: To clone and express the recombinant capsid protein VP2 of enterovirus type 71 (EV71) and to identify the immune activity of expressed protein in order to build a basis for the investigation work of vaccine and diagnostic antigen. METHODS: VP2 gene of EV71 was amplified by PCR, and then was cut by restriction enzyme and inserted into expression vector pMAL-c2X. The positive recombinants were transferred into E.coli TB1, the genetically engineered bacteria including pMAL-c2X-VP2 plasmids were induced by isopropyl thiogalactoside ( IPTG) , and the expression products were analyzed by SDS-PAGE and western blotting method. EV71 IgM antibody detection method by ELISA was set up, and the sensitivity and specificity of this method was assessed; 60 neutralizing antibody positive serum samples from hand foot and mouth disease (HFMD) patients were determined, of which 52 samples were positive and 8 samples were negative; a total of 88 acute phase serum samples of HFMD patients diagnosed in clinical were also detected. RESULTS: VP2 gene of 762 bp was obtained by PCR, the gene segment inserted into the recombinant vector was identified using restriction enzyme digestion. The recombinant vector could express a specific about 71 500 fusion protein in E.coli by SDS-PAGE. The purified recombinant protein of EV71-VP2 can react with the serum of HFMD patients to produce a specific band by western blotting. The sensitivity and specificity of ELISA was 87% and 83%, respectively. Of the 88 acute phase serum samples from children with HFMD, 48 samples (55%) were positive by the ELISA assay. CONCLUSIONS: VP2 gene of EV71 has been cloned and a prokaryotic high expression system for VP2 gene was successfully constructed in the present study. The recombination EV71-VP2 has well antigenicity, which could be useful for developing diagnose reagent or vaccine of EV71.

Recombination in human coxsackievirus B5 strains that caused an outbreak of viral encephalitis in Henan, China.

In 2011, human coxsackievirus B5 (CVB5) caused an outbreak of viral encephalitis in Henan, China. Complete genome sequence analysis based on two isolates showed that the 5' half of the genome (nt 1-4540) had high similarity (>97 %) to that of CVB5 strain GU376747, and the 3' half (nt 4700-7402) showed high similarity (>96 %) to that of human coxsackievirus B3 (CVB3) strain GQ141875. These isolates had the highest similarity (97.7 %) to the Changchun strain, based on the complete genome, rather than to other CVB5 strains isolated from Henan in recent years. There were therefore at least two groups of CVB5 circulating in Henan Province, which evolved at different rates.

[Establishment of indirect immunofluorescence assay (IFA) for detection of IgG antibody against new bunyavirus].

OBJECTIVE: To develop an indirect immunofluorescence assay (IFA) for detection of IgG antibodies against new bunyavirus. METHODS: The antigen slides were prepared with 5 new bunyavirus strains isolated using Africa green monkey kidney (Vero) cells. Specificity and sensitivity evaluation of IFA were carried out by optimizing working conditions of IFA. Using established IFA, serum samples from both acute and recovery phases were tested for 126 cases with fever thrombocytopenia and leukopenia syndrome in Xinyang, Henan province in 2007 - 2011. The results were compared with detections by RT-PCR. RESULTS: The new bunyavirus stable immunofluorescence specific WZ69 strain was selected to prepare antigen slides of IFA. The optimum conditions of IFA were: optimum dilution for primary antibody (serum) and secondary antibody (isosulfocyanic acid fluorescence marked goat anti-human IgG antibody) was 1:40 and 1:150 respectively. The optimum dilution for Evans blue in secondary antibody was 1:20 000. Among the 126 patients, 96 paired serum specimens were tested positive to the new bunyavirus and 30 patients were tested negative to the virus. The positive rate of antibodies was 76.19%. There was no significant difference in results between IFA and RT-PCR (72.22% (91/126)) (P > 0.05). CONCLUSION: The IFA has high sensitivity and specificity with easy operation. It can be used in detecting the new bunyavirus infection in patients with fever, thrombocytopenia and leukopenia syndrome.

[Etiology surveillance of hand-foot-mouth disease in Henan province between 2008 and 2011].

OBJECTIVE: To understand etiological types and distribution features of hand-foot-mouth disease (HFMD) in Henan province between 2008 and 2011. METHODS: A total of 30 486 specimens of feces, rectal swabs or throat swabs from HFMD patients were collected by each Municipal CDC in Henan from 2008 to 2011. The enterovirus 71 (EV71), coxsackie virus A16 (CA16) and other enterovirus (EV) were detected by RT-PCR or real time RT-PCR. The VP1 gene of EV71 was amplified and the sequences were analyzed by bioinformatics software. A genetic evolution tree of the sequence was constructed as well. RESULTS: The positive rates of EV71, CA16 and other EV were 62.70% (11 209/17 876), 12.03% (2150/17 876), 25.27% (4517/17 876) in 17 876 laboratory diagnosed cases, respectively. The differences were statistically significant (χ(2) = 157.17, P < 0.05). The positive rates of EV71, CA16 and other EV were 63.40% (7370/11 624), 11.58% (1346/11 624) and 25.02% (2908/11 624) in male patients and 61.40% (3839/6252), 12.86% (804/6252) and 25.74% (1609/6252) in female patients, respectively. The differences were statistically significant (χ(2) = 4.06, P < 0.05). The children under 5 years old were high-risk population of HFMD, accounting to 97.67% (17 459/17 876) of the laboratory-diagnosed patients.86.92% (15 537/17 876) cases were children between 1 to 3 years old. Constituent ratio of EV71 changed seasonally during a year, there was a high infection ratio of EV71 between April and June, especially in May, the infection ratio reached 69.34% (2384/3438). The positive rates of EV71, CA16 and other EV were 82.48% (5715/6929), 1.76% (122/6929) and 15.76% (1092/6929) among the 6929 laboratory-diagnosed severe cases, respectively. The positive rates of EV71 was higher than CA16 and other EV (χ(2) = 9259.17, 6170.81, P < 0.05, respectively). There were 117 deaths because of severe HFMD, 55 (47.01%) of which were laboratory confirmed. 50 death cases were infected by EV71, and according to the genetic evolution analysis, the VP1 gene of EV71 strain was belonged to subtype C4 of gene C. CONCLUSION: The EV71 and CA16 were the main pathogens which caused HFMD in Henan province, and EV71 virus was the dominant strain, belonging to C4 subtype of gene C.

[Epidemic characteristics and viral antibody level among healthy people of Japanese B encephalitis in Henan province in 2010].

OBJECTIVE: To understand the epidemic characteristics and viral antibody level among healthy people of Japanese B encephalitis (JE) in Henan province in 2010. METHODS: A total of 433 selected JE cases in Henan province in 2010 were analyzed by descriptive epidemiological method. Xinyang and Luoyang were selected as survey sites in 2010.12 administrative villages were randomly selected from both cities. As the investigation objects, 519 healthy people from the two cities were randomly selected by eight age groups:less than one year old, 1 - 2 years old, 3 - 4 years old, 5 - 6 years old, 7 - 14 years old, 15 - 19 years old, 20 - 59 years old, and above 60 years old. A total of 1008 samples of blood specimens were collected both in May and November, and JE viral antibody was detected by micro-cytopathic effect neutralization test. RESULTS: The incidence rate of JE was 0.46/100 000 (433/94 130 434) in Henan province in 2010.97.69% (423/433) of the patients were found between July and September, and 81.06% (351/433) were distributed in Nanyang, Xinyang, Luoyang, Zhumadian and Zhoukou city. Children aged 0 to 14 years were the primarily affected group (82.22%, 356/433), the people above 15 years old accounted for 17.78% (77/433) of whole cases in Henan province, but the same group accounted for 65.79% (50/76) of whole cases in Luoyang city, which obviously higher than the percentage in Henan province (χ(2) = 79.57, P < 0.05). Most patients were scattered children in Henan province, accounting for 58.89% (255/433). In Luoyang city, most patients were peasants, accounting for 44.74% (34/76). The antibody positive rate of JE among health people above 15 years old in Luoyang city was 48.94% (46/94), which was lower than it in Xinyang city at 97.78% (88/90). The difference showed statistical significance (χ(2) = 55.42, P < 0.05). The antibody positive rate among healthy people under vaccination was 50.41% (61/121), which was obviously higher than that among people without vaccination, at 16.67% (6/36) in Luoyang city. The difference showed statistical significance (χ(2) = 12.92, P < 0.05). The antibody positive rate among healthy people under vaccination was 67.11% (51/76) in Xinyang city, which was obviously higher than that among people without vaccination, at 46.39% (45/97). The difference showed statistical significance (χ(2) = 7.40, P < 0.05). CONCLUSION: The incidence of JE showed seasonal and regional characteristics, there were differences among ages and occupations. The difference was consistent with the difference in viral antibody level among health people in Henan province and Luoyang city.

[Etiology survey on an outbreak of viral encephalitis].

OBJECTIVE: To isolate and identify the pathogen that caused an outbreak of viral encephalitis in Henan province in 2010; and to analyze the genetic characteristic of gene viral protein1(VP1) on the viral strains isolated. METHODS: During the period of the outbreak of viral encephalitis in Lushan county, Pingdingshan city, Henan province, eight hospitalized patients were recruited in the study. All the patients' feces samples were collected. Three patients' cerebrospinal fluids samples and another four patients' serum samples were collected separately. The virus in the samples were isolated and identified by enterovirus (EV) combined serum. The VP1 gene of the positive isolate was amplified by reverse transcriptase PCR method, and its nucleotide sequence was detected and the genetic evolution was analyzed. RESULTS: Fifteen samples were collected in total, including 8 feces samples, 3 cerebrospinal fluids samples and 4 serum samples. The results of Fluorescence Quota PCR detection showed that 11 out of 15 samples were positive; 2 strains of virus were isolated from 2 feces samples and the serotype were all Coxsackie-positive identified by the EV combined serum. The full-length VP1 genetic sequences were all 849 bp, and showed 77.1% - 96.9% similar to the nucleotide and 95.8% - 100% similar to the amino acid of CoxB5. The analysis showed that the genetic evolution tree was just the same with Genotype-D. CONCLUSION: CoxB5 whose genotype was Genotype-D, was the pathogen that caused the outbreak of viral encephalitis in Lushan county, Pingdingshan city, Henan province.

Emergence and transmission pathways of rapidly evolving evolutionary branch C4a strains of human enterovirus 71 in the Central Plain of China.

BACKGROUND: Large-scale outbreaks of hand, foot, and mouth disease (HFMD) occurred repeatedly in the Central Plain of China (Shandong, Anhui, and Henan provinces) from 2007 until now. These epidemics have increased in size and severity each year and are a major public health concern in mainland China. PRINCIPAL FINDINGS: Phylogenetic analysis was performed and a Bayesian Markov chain Monte Carlo tree was constructed based on the complete VP1 sequences of HEV71 isolates. These analyses showed that the HFMD epidemic in the Central Plain of China was caused by at least 5 chains of HEV71 transmission and that the virus continued to circulate and evolve over the winter seasons between outbreaks. Between 1998 and 2010, there were 2 stages of HEV71 circulation in mainland China, with a shift from evolutionary branch C4b to C4a in 2003-2004. The evolution rate of C4a HEV71 was 4.99×10(-3) substitutions per site per year, faster than the mean of all HEV71 genotypes. The most recent common ancestor estimates for the Chinese clusters dated to October 1994 and November 1993 for the C4a and C4b evolutionary branches, respectively. Compared with all C4a HEV71 strains, a nucleotide substitution in all C4b HEV71 genome (A to C reversion at nt2503 in the VP1 coding region, which caused amino acid substitution of VP1-10: Gln to His) had reverted. CONCLUSIONS: The data suggest that C4a HEV71 strains introduced into the Central Plain of China are responsible for the recent outbreaks. The relationships among HEV71 isolates determined from the combined sequence and epidemiological data reveal the underlying seasonal dynamics of HEV71 circulation. At least 5 HEV71 lineages circulated in the Central Plain of China from 2007 to 2009, and the Shandong and Anhui lineages were found to have passed through a genetic bottleneck during the low-transmission winter season.

[Surveillance on Japanese encephalitis in Henan province, 2006 - 2010].

OBJECTIVE: To analyze the epidemiological characteristics and risk factors of Japanese encephalitis (JE) in Henan province. METHODS: Epidemiological characteristics and related factors of JE cases in Henan province from 2006 to 2010 were analyzed with descriptive epidemiological method and JE IgM antibodies of the serum or cerebrospinal fluid of the cases were detected by ELISA. RESULTS: 3099 cases were reported in Henan province from 2006 to 2010. The incidence fluctuated from 0.39/100 000 to 1.08/100 000, and the incidence rate was decreasing. Patients were concentrated mainly in Xinyang, Nanyang and Luoyang cities, which accounted for 60.12% of the total. The peak season was in July-September, accounted for 93.26% of all the cases. Most cases were in 0 - 14 year old (83.61%) in the whole province. However, in Luoyang city, number of cases in the ≥ 15 year old group, had an obvious increase (57.63%). Compared with the provincial data, significant difference was found between the two ≥ 15 year old groups (χ(2) = 330.0341, P < 0.05) statistically. 20.23% of the JE cases were vaccinated but 75.54% of them did not complete the whole course. 79.77% of the cases were not sure if they had received the vaccination. 42.98% of the JE cases were confirmed through laboratory tests but other 45.95% of them were clinically diagnosed, with the rest 11.07% were suspected cases. CONCLUSION: The distribution of JE cases showed seasonal, regional characteristics and crowd differences in Henan province. Basic immunization and the program on strengthening immunization of JE should be further standardized. The laboratory diagnosis rate of JE cases should be further improved.

[The prevalence characteristic and prevention strategy of Japanese B Encephalitis in Henan province].

OBJECTIVE: To analyze the prevalence trend, prevalence characteristics and influence factors of Japanese B Encephalitis (JE) in Henan province. METHODS: The data that of 64 401 JE patients in Henan from 1980 to 2008 were statistically analyzed by SPSS12.0 and EXCEL2003 software. Luoshan, Xinan, Xihua, Deng county and Hua county were chosen as monitoring sites. The mosquito specimens were gathered with the artificial hour method and the mosquito curtain method, the mosquito density was calculated one time each ten day period from May to July. At the same time, 30-40 newborn pig blood samples were gathered each ten-day period and the pig serum JE IgG antibody was detected by ELISA method. RESULTS: The Cumulative incidence of JE was 64 401 cases in Henan province from 1998 to 2008, the range of incidence rate was from 0.34/100 000 (315/93 599 969) to 6.72/100 000 (5246/78 076 567); The average incidence of JE was 4.39/100 000 (3530/80 381 469) from 1980 to 1994; The average incidence of JE was 0.86/100 000 (811/94 217 549) from 1995 to 2008; In 2008, the incidence rate reached the lowest point for 0.34/100 000 (315/93 599 969); The incidence occurred mainly in July-September, accounting for 89.40% of the total cases (57 572/64 401); the patients were concentrated mainly in 5 cities, which were Xinyang, Nanyang, Zhumadian, Zhoukou, Luoyang, accounting for 81.02% (52 175/64 401). The 0 - 14 years old age group was the dominant group (79.01%, 50 884/64 401). In Luoyang city, incidence of >/= 15 years old group was significantly increased (57.83%, 2120/3666), the constitution of JE incidence were significantly different between 0 - 14 years old group and >/= 15 years old age group (chi(2) = 2705.32, P < 0.05) in Henan province and Luoyang city. The different density of the mosquitoes and the different positive-times for 50% of the antibodies of JE in piglets on the monitor sites showed the intensity of JE disease. CONCLUSION: The incidence of JE showed a decreasing trend, seasonal, regional characteristics and age distribution difference in Henan province. The monitoring of host animal pig JE antibody level and the medium mosquito density may forecast the JE prevalence tendency. To control the incidence in the younger groups in Henan province, older age group in Luoyang city and high-incidence areas, it is important to strengthen the monitoring and forecasting measures to prevent JE in Henan province.