Outbreak of dengue Fever in central China, 2013.

In 2013, the first dengue fever (DF) outbreak in central China was reported in the central of Henan province, northern temperate regions, although they have been sequentially recorded in Southern China. 106 suspected DF cases were reported and 73 patients were confirmed dengue virus type 3 (DEN-3) infections. 62/392 (15.8%) local health persons showed DEN antibodies positive. To this day Henan is the northernmost province in China which has been reported about outbreak of DF and what is important is that it warns us the endemic range of DF has been expanded geographically in China.

[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 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.

[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 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.

[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.

Distribution of Avian Influenza A Viruses in Poultry-Related Environment and Its Association with Human Infection in Henan, 2016 to 2017.

OBJECTIVE: To survey avian influenza A viruses (AIVs) in the environment and explore the reasons for the surge in human H7N9 cases. METHODS: A total of 1,045 samples were collected from routine surveillance on poultry-related environments and 307 samples from human H7N9 cases-exposed environments in Henan from 2016 to 2017. The nucleic acids of influenza A (Flu A), H5, H7, and H9 subtypes were detected by real-time polymerase chain reaction. RESULTS: A total of 27 H7N9 cases were confirmed in Henan from 2016 to 2017, 24 had a history of live poultry exposure, and 15 had H7N9 virus detected in the related live poultry markets (LPMs). About 96% (264/275) Flu A positive-environmental samples were from LPMs. H9 was the main AIV subtype (10.05%) from routine surveillance sites with only 1 H7-positive sample, whereas 21.17% samples were H7-positive in H7N9 cases-exposed environments. Samples from H7N9 cases-exposed LPMs (47.56%) had much higher AIVs positive rates than those from routine surveillance sites (12.34%). The H7+H9 combination of mixed infection was 78.18% (43/55) of H7-positive samples and 41.34% (43/104) of H9-positive samples. CONCLUSION: The contamination status of AIVs in poultry-related environments is closely associated with the incidence of human infection caused by AIVs. Therefore, systematic surveillance of AIVs in LPMs in China is essential for the detection of novel reassortant viruses and their potential for interspecies transmission.

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.

[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.

[Genetic characterization of echovirus 25 isolated from Henan].

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.

[Surveillance and control of Japanese encephalitis in Henan province, 1950 - 2008].

OBJECTIVE: To analyze the characteristics and trend of Japanese encephalitis (JE) in Henan province. METHODS: Adopting descriptive epidemiological method to analyze the data on the epidemic situation of JE from 1950 to 2008, and on mosquitoes and host animals at disease surveillance points. The host serum JE IgG antibody was detected by ELISA. Data was analyzed using SPSS 12.0 and Excel 2003 software. RESULTS: The incidence of JE in Henan province had a fluctuant downward trend. Peak of the incidence fell in July to September, accounting for 88.09% of total cases. The scope of geographical distribution was increasing from northern to southern parts of the province. Cases mainly concentrated in the southern and south-eastern parts of the province. 0 - 14 year-old group had the highest incidence (81.95%). In Luoyang city, there was a significant increase in children at 15-years or older (58.93%). Most patients were farmers (42.33%). The positive-times for half of the antibodies of JE in piglets of the surveillance sentinels were different, which might be the reason for the different levels for the incidence rates. The proportion of different kinds of mosquitoes were also different in surveillance sentinel sites, and the time for the density peak of the mosquitoes was in accordance with the incidence peak of JE. CONCLUSION: To develop control strategies, evidence should be based on the characteristics of geographical variance, age, occupation differences, data related to monitoring on animal host and media mosquitoes of JE incidence in Henan province.

[Complete genome sequencing of enterovirus 71 (EV71) HENAN08 strain isolated in Henan province].

OBJECTIVE: To sequence the whole-genome of enterovirus 71 (EV71) srtain isolated from patient with hand, foot and mouth in Henan province in 2008. METHODS: Eight overlapping clones covering the whole viral genome were obtained by RT-PCR and the sequences were determined by Sanger dideoxg-mediated chain termination method. RESULTS: Data it showed that the full length of enterovirus 71 (EV71) HENAN08 genome (not including Poly A tail) is 7405 bp. No deletion or insertion was detected in the coding region. There were several deletions and insertions in 5'UTR and 3'UTR regions. In P1 region, HENAN08 strain shared high homology with AnhuiFY08 strain, Zhejiang08 strain and SHZH strains (SHZH98, SHZH03) but low homology with Cox. A16. In P2 and P3 regions, HENAN08 strain shared higher nucleotide homology with Cox. A16 (81.7% and 83.7%) than that with BrCr and TW2086 strains. The phylogenetic analysis based on P1 region demonstrates that HENAN08 strain had the nearest genetic relationship with AnhuiFY and Zhejiang strains (isolated in 2008). CONCLUSION: The HENAN08 strain might belong to the same genogroup with AnhuiFY08 and Zhejiang08 strains as C4 gene subtypes.

[Laboratory testing of specimens from patients with viral encephalitis from some regions of China].

OBJECTIVE: To understand the viral etiology of viral encephalitis in China by detecting IgM antibody and viral RNA in the clinical samples of patients from some provinces of China by enzyme-linked immunosorbent assay and polymerase chain reaction. METHOD: Serum and cerebrospinal fluid samples of 771 patients with viral encephalitis or meningitis were collected from six provinces of China and were stored at -20 degrees C or -70 degrees C. Enzyme-linked immunosorbent assays were used for detection of IgM antibody to Japanese encephalitis virus, coxsackievirus, echovirus, herpes simplex virus, measles virus, varicella-zoster virus, mumps virus, cytomegalovirus and Epstein-Barr virus. Polymerase chain reaction was applied for the detection of viral RNA of enteroviruses and seadornavirus. RESULTS: IgM antibody was detected in 567 of 771 (73.5%) cases. The most common pathogen was Japanese encephalitis virus (47.0%, 362/771), followed by mumps virus (10.6%, 82/771), enteroviruses (8.8%, 68/771), herpes simplex virus (5.7%, 44/771), measles virus (0.4%, 3/771), varicella-zoster virus (0.4%, 3/771), Epstein-Barr virus (0.4%, 3/771), and cytomegalovirus (0.3%, 2/771). Enterovirus was positive in 8 cases, seadornavirus was negative in all the cases by PCR. CONCLUSION: According to the study, Japanese encephalitis was the most important encephalitis in China. Mumps virus was another important pathogen. Enteroviruses and herpes simplex virus were also important pathogens.