Résumé
Objective:To analyze the specific immunoglobulin G (IgG) antibodies level in the population after the coronavirus disease 2019 (COVID-19) pandemic in Henan Province.Methods:A total of 5 178 peripheral venous blood samples were collected from 10 districts (counties) in Henan Province according to the national seroepidemiological survey program for COVID-19, and the method of cluster random sampling was adopted from March 6 to 15, 2023. Descriptive analysis was used for the basic data, history of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination, SARS-CoV-2 infection of the respondents. The specific IgG antibody of SARS-CoV-2 was detected using chemiluminescence method. Statistical analysis was performed by using rank sum test, Kruskal Wallis test, and Dunn′s test.Results:The overall positive rate of SARS-CoV-2-specific IgG antibody was 83.35%(4 316/5 178). There were statistically significant differences in the specific IgG antibodies against SARS-CoV-2 produced by people of different sexes, different ages, infected or not, vaccinated or not, and vaccinated with different doses of SARS-CoV-2 vaccine ( Z=3.60, H=195.32, Z=6.10, 18.08, H=382.70, respectively, all P<0.001). The specific IgG antibodies produced by unvaccinated+ uninfected group, unvaccinated+ infected group, vaccinated+ uninfected group, and vaccinated+ infected group were 3.54(0.98, 11.00), 60.65(2.33, 84.80), 133.00(59.80, 173.00), and 142.00(98.30, 176.00), respectively. And the difference was statistically significant( H=354.62, P<0.001). The specific IgG antibodies of uninfected people increased with the increase of inoculum times( H=287.00 and 98.48, both P<0.001). The specific IgG antibodies of people who were not infected with SARS-CoV-2 in the groups of whose interval from the last inoculation of SARS-CoV-2 vaccine to blood collection was less than three months, three to six months and more than six months were 171.86(156.04, 196.57), 71.71(17.08, 110.38) and 132.14(57.59, 172.25), respectively, and the difference was statistically significant ( H=19.93, P<0.001). Among them, the absolute difference between the less than three months group and the three to six months group was statistically significant ( Z=3.67, P<0.001), and the absolute difference between the less than three months group and the more than six months group was statistically significant ( Z=3.47, P<0.001). The specific IgG antibodies level in the less than three months group was the highest. Conclusions:There is a certain correlation between the number of SARS-CoV-2 vaccine doses and the specific IgG antibodies level in uninfected people. The specific IgG antibodies could maintain a high level for three months after immunization.
Résumé
Objective:To analyze the epidemiological characteristics and spatiotemporal characteristics of human brucellosis in Henan Province.Methods:Data of human brucellosis in Henan Province from 2005 to 2021 were collected through the China Disease Prevention and Control Information System, and a descriptive epidemiological method was used to analyze the epidemic profile of brucellosis in Henan Province and the three distribution characteristics. Global and local spatial autocorrelation were used to analyze the spatial distribution and the hot spots of brucellosis in Henan Province, respectively, and spatiotemporal scanning was used to analyze the spatiotemporal clustering regions of brucellosis in Henan Province.Results:A total of 39 862 brucellosis cases were reported in Henan Province from 2005 to 2021, with an average annual incidence of 2.44/100 000, and the number of cases showed an overall increasing trend each year (χ 2trend = 11 127.85, P = 0.001). The onset months were mainly concentrated from March to July, accounting for 59.00% (23 517/39 862), with May as the peak (5 478 cases). Cases of brucellosis were reported in 157 counties (cities, districts) of the province. The ratio of male to female was 2.52∶1.00 (28 542/11 320). Farmers were the main occupation, with 32 985 cases (82.75%). The age of onset was mainly 45 to 65 years old, with 20 226 cases (50.74%). The global spatial autocorrelation analysis showed that the global Moran's I was > 0, Z > 1.96, and P < 0.05 in all years except 2006 - 2008, showing spatial clustering. Further local spatial autocorrelation analysis was performed, and high-high and low-low clustering areas existed in 2012 - 2021 ( P < 0.01). Spatiotemporal scanning analysis showed that there was one spatiotemporal cluster in the high incidence area and two spatiotemporal clusters in the low incidence area. The high incidence cluster was centered in Neixiang County, covering 48 counties (cities, districts) including Song County and Ruzhou City, and the aggregation time was from 2014 to 2021. The two low incidence clusters were centered in Yongcheng City and Boai County, covering 58 and 18 counties (cities, districts), respectively, and the aggregation time was 2016 - 2021 and 2005 - 2012, respectively. Conclusion:The overall incidence of brucellosis in Henan Province is on the rise from 2005 to 2021, with middle-aged and elderly male farmers as the main affected population, and there are spatiotemporal clusters of brucellosis in Henan Province.
Résumé
Objective:To analyze the whole genome of Omicron variants causing the first local Omicron outbreak in Henan Province and to investigate the mutations in the SARS-CoV-2 genome for source tracing.Methods:Respiratory tract samples from COVID-19 cases in the Omicron outbreak in Henan Province from January 7 to 29, 2022 were subjected to whole-genome sequencing and sequence alignment analysis. Whole-genome identity, variations and evolution of the Omicron variants were analyzed.Results:Through high-throughput sequencing, the whole-genome sequences of SARS-CoV-2 were obtained from 120 cases, which accounted for 25.64% (120/468) of all COVID-19 cases in Anyang during the same period. Compared with the genome of Wuhan reference strain (NC_045512.2), there were 57-59 nucleotide mutation sites in the 120 whole genome sequences, and one or two nucleotide mutation sites were added to the shared 57 nucleotide sites. All of the 120 strains were VOC/Omicron (BA.1.1) variants and shared high homology. The whole-genome sequence obtained from the first case A contained 57 nucleotide mutation sites, while apart from the 57 identical nucleotide mutation sites, one specific mutation site (C1594T) was found in the whole-genome sequence obtained from the first case B, suggesting that the two cases were in the same transmission chain. After comparing with the database of domestic and imported cases by the Chinese Center for Disease Control and Prevention and the Henan Provincial Center for Disease Control and Prevention, it was found that the current outbreak was linked with the same transmission chain as the existing local epidemics in other provinces. Moreover, epidemiological investigation showed that on January 2, case A had come into contact with her cousin and his family who returned from an affected area outside the province.Conclusions:Based on the gene sequencing results and epidemiological investigation, the COVID-19 outbreak in Anyang city, Henan Province was a local epidemic and the source of it was a college student who returned to Anyang city from other province on December 28, 2021. These infections were linked to the same transmission chain as the existing local infection in other provinces.
Résumé
Objective:To report the first case of sever fever with thrombocytopenia syndrome caused by severe fever with thrombocytopenia syndrome virus (SFTSV) in Puyang city, and to study the epidemiological and molecular characteristics of S, M, L fragments of the SFTSV isolate.Methods:The epidemiological characteristics of this case was analyzed with epidemiological methods. SFTSV was isolated from the patient′s serum sample. Nucleic acid of SFTSV was extracted and detected by fluorescent RT-PCR. A multiplex PCR method was constructed to amplify the nucleic acid sequence of the virus. whole-genome sequencing was performed on the next-generation sequencing platform. MEGA11 and DNAStar was used for homology analysis and a phylogenetic tree was constructed.Results:Epidemiological investigation showed that the patient and his close contacts had no history of travel or tick bite within 14 d, but had a history of fieldwork. The patient′s serum sample was positive for SFTSV nucleic acid. Genetic analysis showed that the S, M, L gene fragments of the first SFTSV isolate in Puyang belonged to genotype E. This isolate shared 94.8%-99.6%, 94.0%-99.8% and 95.7%-99.7% nucleotide sequence homology with the representative strains acquired from GeneBank in S, M, L gene fragments, respectively.Conclusions:This case was the first case of SFTSV-caused severe fever with thrombocytopenia syndrome in Puyang. The SFTSV isolate shared a close homology with domestic isolates, but its genotype was significantly different from the SFTSV strains isolated in Henan in recent years, indicating that it might an imported case from other places in Henan Province or Hubei Province. Disease monitoring and professional training for medical personnel should be strengthened and more attention should be paid to the evolution and mutation of SFTSV.
Résumé
Objective:To analyze and summarize the epidemiological and molecular characteristics of SARS-CoV-2 Delta variant, a variant of concern (VOC), in Henan Province in 2021 in order to provide a basis for epidemic prevention and control.Methods:According to the feedback of sequencing results from Chinese Center for Disease Control and Prevention, 111 patients infected with SARS-CoV-2 Delta VOC were selected from the Henan imported and local cases in 2021. Basic patient information was obtained from the pandemic website. The differences in age, gender, vaccination history, the number of vaccine doses and different clinical types were analyzed. Moreover, the differences in RT-qPCR results of ORF1 ab gene and N gene Ct values between cases of different genders and symptoms were analyzed statistically. Sequencing results of the nucleotide and S protein mutation sites were analyzed. Results:There was no significant difference in the gender distribution of 111 cases between different age groups (χ 2=2.217, P=0.529). There was also no significant difference in clinical types between patients with different vaccination history (χ 2=12.074, P=0.209). The Ct values of most SARS-CoV-2 nucleic acid-positive specimens were distributed in the lower range and the viral loads were higher. The difference in the Ct value of ORF1 ab gene between different gender groups was not statistically significant (χ 2=1.646, P=0.439), but were significantly different among asymptomatic, mild, normal, and severe cases (χ 2=13.257, P=0.039). There was no significant difference in N gene Ct value among cases of different genders or different symptoms (all P>0.05). The 111 patients in this study were mainly found through close-contact screening and full-staff nucleic acid screening and accounted for 62.2% (69 cases) of the total. The sequencing length coverage was basically greater than 99% (accounting for 90.1%, 100/111); the total number of nucleotide mutation sites was mostly in the range of 46-50 (86.4%, 89/103); the total number of S protein mutation sites was mostly 12 (82.5%, 85/103). The 103 Delta mutants all contained nine mutation sites, which were T19R, R158G, L452R, T478K, D614G, P681R, D950N, E156del and F157del, with a mutation rate of 100%. Conclusions:People were highly susceptible to the SARS-CoV-2 Delta in Henan Province in 2021. High viral load and increase in the ORF1 ab gene load would aggravate the clinical symptoms.
Résumé
Objective:To analyze the genome characteristics and variations in nucleotides and amino acids of SARS-CoV-2 causing an outbreak in Henan Province in November 2021 and perform the traceability analysis.Methods:In this study, throat swab specimens from cases in the acute phase were collected and tested for the nucleic acids of SARS-CoV-2 by real-time fluorescent RT-PCR. SARS-CoV-2 nucleic acid-positive samples were subjected to high-throughput genome sequencing and whole-genome alignment analysis.Results:The median Ct values of ORF1ab gene and N gene in 70 positive specimens was 26.41 (15.58 to 39.27) and 24.43 (12.04 to 39.74), respectively. Compared with the sequence of Wuhan-Hu(NC_045512) reference strain, 47 to 49 nucleotide mutations sharing 47 nucleotide mutation and 41 amino acid mutations were found in 63 strains of successfully sequenced SARS-CoV-2. Nine nucleotide mutations and 12 amino acid mutations were found in the spike protein. The index case shared 47 mutations with the Russian imported cases in Henan Province on October 14 and the local cases in Jiangxi Province in October. Moreover, their genomes were highly homologous and they all belonged to the Delta variant (AY.122 evolutionary branch).Conclusions:Continuous monitoring of imported COVID-19 cases and prolonging the period of quarantine were needed to reduce the risk of local outbreak and epidemic caused by imported COVID-19 cases. Analysis of the genomic characteristics of SARS-CoV-2 and the variations in nucleotides and amino acids was conducive to trace the origin of COVID-19 outbreak quickly and provide reference for precise control.
Résumé
Objective:To establish a sequencing method for the genome of severe fever with thrombocytopenia syndrome virus (SFTSV) based on next-generation sequencing (NGS).Methods:SFTSV RNA was extracted from serum samples of patients with severe fever with thrombocytopenia syndrome. SFTSV-specific primers were designed using Primer 5.0 software. A multiplex PCR method was constructed and used to amplify the nucleotide sequence of SFTSV. Whole-genome sequencing was performed on the NGS platform.Results:The whole genes of SFTSV isolates in 28 serum samples were amplified by the multiplex PCR with a coverage over 94%. Sequencing and phylogenetic analysis of those strains revealed that the predominant strains ( n=20) belonged to genotype A, followed by genotypes B ( n=4) and E ( n=3). Conclusions:A high-throughput sequencing method for SFTSV based on multiplex PCR was established in this study. This method was characterized by high specificity and good quality and could improve the sequencing efficiency.
Résumé
Objective:To monitor the changes in specific IgM and IgG antibodies in patients diagnosed with COVID-19 after SARS-CoV-2 infection, and analyze their clinical significance.Methods:A total of 168 serum samples were collected from 56 COVID-19 patients with different disease courses who were positive for nucleic acid test at Henan Center for Disease Control and Prevention on January 8, 2020 and February 21, 2020. Serum samples from 25 healthy people excluded from COVID-19 were used as control group. IgM and IgG antibodies against SARS-CoV-2 were detected by chemiluminescence method.Results:IgM antibody increased sharply in 1-3 weeks after onset, and reached the peak value (21.78 AU/ml) in the 3rd week after onset. IgG antibody increased the most in 3-6 weeks after onset, and reached the peak value (81.58 AU/ml) in the 9th week after onset. The levels of IgM and IgG antibodies were closely correlated with age and disease course ( P<0.05). The antibody level of 30-60 years old group was the highest, the IgM antibody positive rate and antibody level of acute stage and previous infection were lower than that of recovery stage, and the IgG antibody positive rate and antibody level of acute stage were lower than that of recovery stage and previous infection. During the whole course of the disease, the levels of IgM and IgG antibodies increased gradually in the acute stage, reached the peak in the recovery stage, and decreased and maintained at a certain level in the past infection. Conclusions:Serum SARS-CoV-2 IgM and IgG antibody detection can be used as auxiliary diagnostic indicators for COVID-19, and its continuous observation is helpful for epidemiological investigation, serological diagnosis and disease course monitoring.
Résumé
Objective:To provide data support for the prevention and control of dengue fever in Henan Province by analyzing the molecular epidemiological and etiological characteristics of dengue fever outbreaks in Puyang in 2019.Methods:Blood samples were collected from all suspected cases of dengue fever. The antigen, antibody and nucleic acid of dengue virus (DENV) were detected. The E gene was amplified by viral nucleic acid extraction and sequenced. Phylogenetic tree was constructed to trace the source of infection. Results:A total of 61 local cases of dengue fever were reported, and no deaths were reported. Among them, 4 cases (72.13%) were positive for DENV NS1 antigen; 16(26.23%) cases were positive for specific IgM; 38(62.30%) cases were positive for specific IgG; 34 cases (54.10%) were positive for dengue nucleic acid testing. Ten dengue virus strains were isolated, all of which were dengue virus type 1(DENV-1). Sequence analysis of E gene suggested it belonged to the same clade as Henan201903 strain imported from Cambodia to Zhumadian, Henan in 2019, with the highest homology. Conclusions:The dengue fever epidemic in Henan Province was caused by DENV-1, which might be improted from Cambodia, Singapore, Myanmar and other Southeast Asian countries. Therefore, the surveillance of DENV in people returning from Southeast Asia should be strengthened.
Résumé
Objective:To analyze the evolutionary characteristics and variations of 2019 novel coronavirus (2019-nCoV) strains imported from abroad in Henan Province.Methods:A total of 16 imported cases of coronavirus disease 2019 (COVID-19) reported in Henan Province from May to December 2020 were enrolled. The throat swab specimens from the patients were collected and sent to the Henan Provincial Center for Disease Control and Prevention for whole genome sequencing. Taking SARS-CoV-2 Wuhan-Hu-1 published in Global Initiative on Sharing All Influenza Data (GISAID) as the reference sequence, the sequences were aligned and analyzed by MEGA X, and the phylogenetic tree was constructed by the maximum likelihood method.Results:Among 16 cases, 13 cases were imported from Russia, two cases were imported from Myanmar, and one case was imported from Ukraine. A total of 16 strains of 2019-nCoV genomes with the lengths of 29 804 bp to 29 882 bp were obtained. A total of 145 nucleotide mutations and 80 amino acid mutations were detected. Nucleotide variations of C241T, C3037T, C14408T, A23403G and the amino acid variation of D614G in spike protein were detected in all sequences. Meanwhile, insertion A at the site of 29704 was found in BetaCov/HEN02/Human/2020, BetaCov/HEN04/Human/2020 and BetaCov/HEN05/Human/2020. Deletion variation was not found. Phylogenetic analysis showed that there was no correlation between the 16 strains and currently epidemic variants of concern (VOC) .Conclusion:From May to December 2020, the detection of viral genome mutations in the imported cases of Henan Province shows randomness and diversity, while the strains are not VOC.
Résumé
Objective:To explore the serotype distribution and drug resistance of Shigella in stool samples of children under five years old with diarrhea from 2008 to 2017 in Sui County, Henan Province. Methods:A total of 4 721 stool samples of children under five years old with diarrhea were collected from Doufuyuan Clinic of Sui County during 2008 to 2017, and Shigella strains were isolated through bacterial culture. The slide agglutination test was used for serotyping of Shigella strains. Two hundred of seventy-one Shigella strains were selected in proportion, and multiple gradient polymerase chain reaction was used to detect virulence genes and Kirby-Bauer agar method was used for drug sensitivity. Trend chi square test was used to analyze the annual trend of drug resistance. Results:The detection rate of Shigella strains in 4 721 fecal samples was 20.69% (977/4 721). A total of 977 Shigella strains were divided into 13 serotypes in two groups, including 77.79%(760/977) Shigella flexneri strains and 22.21%(217/977) Shigella sonnei strains.The top three serotypes detected alternately every year.The dominant gene pattern of Shigella flexneri was Shigella enterotoxin ( shET)-1+ , shET-2+ , invasion plasmid antigen H ( ipaH)+ , invasion-associated locus ( ial)+ , accounted for 84.04%(179/213) and that of Shigella sonnei was shET-1-, shET-2+ , ipaH+ , ial+ , accounted for 46.55%(27/58). The drug resistance rates of 271 Shigella strains to ampicillin, nalidixic acid and tetracycline were more than 90% and the strains were more sensitive to cefepime and ceftazidime.The drug resistance rates to cefotaxime, cefepime, ciprofloxacin, chloramphenicol and sulfamethoxazole/trimethoprim increased year by year, and all had statistically significant differences ( χ2=24.027, 7.232, 6.039, 4.764 and 6.809, respectively, all P< 0.05). There were 98.52%(267/271) strains resistant to more than three kinds of drugs. The resistance rates of Shigella flexneri to ciprofloxacin, norfloxacin, and chloramphenicol were higher than those of Shigella sonnei, and the resistance rates to gentamicin and sulfamethoxazole/trimethoprim were lower than those of Shigella sonnei. The differences were statistically significant ( χ2=31.866, 14.868, 83.036, 68.534 and 14.738, respectively, all P<0.01). Conclusions:The major serotypes of Shigella in children under five years old in Sui County are constantly changing from 2008 to 2017. The dominant gene patterns of different serotypes are different. Most isolated strains have multiple drug resistances, and different serotypes have different resistance profiles.
Résumé
Objective:To investigate the performance of real-time RT-PCR for the detection of SARS-CoV-2 nucleic acid in clinical diagnosis of COVID-19.Methods:Laboratory test data and basic case information of Henan COVID-19 cases were collected from the China′s Infectious Disease Information System as of March 5, 2020. All information was entered by local hospitals and Center for Disease Control and Prevention (CDC). Local hospitals or country CDC were responsible for sampling and municipal CDC was responsible for nucleic acid testing.Results:A total of 6 714 specimens were detected and the positive rate of SARS-CoV-2 nucleic acid was 23.82%. The specimens were collected from 1 200 confirmed cases, 2 178 suspected cases and 77 asymptomatic cases. The nucleic acid diagnosis rate of COVID-19 was 36.96% (1 277/3 455). In all cases, the positive rates of SARS-CoV-2 nucleic acid in nasal swabs, sputum samples and throat swabs were 19.38%, 28.59% and 23.53%, respectively (χ 2=15.896, P<0.01). The positive rate of SARS-CoV-2 nucleic acid in confirmed COVID-19 cases was 63.10%. The positive rates in nasal swabs, sputum samples and throat swabs were 50.80%, 58.71% and 65.21 (χ 2=18.612, P<0.01). The positive rates of SARS-CoV-2 nucleic acid were 43.51%, 23.98%, 22.82%, 12.17%, 14.46% and 13.21% in samples collected on the day of symptom onset and one week, two weeks, three weeks, four weeks, five weeks and above five weeks after the onset, respectively. The positive rates in confirmed cases were respectively 89.03%, 86.57%, 52.30%, 17.53%, 17.69% and 24.14% at those time points. Conclusions:Real-time RT-PCR is the most effective method for early pathogenic diagnosis of COVID-19. The highest detection rate of nucleic acid is achieved within one week after the onset of COVID-19, and the latest time for nucleic acid detection is 38 d after the onset.
Résumé
Objective:To investigate the etiological characteristics and drug resistance of non-typhoid Salmonella isolated from stool samples of children under 5 years old with diarrhea in Henan Province. Methods:Intestinal bacteria were isolated from fecal samples of 4 250 diarrhea children under five years old in five monitoring sites in Henan Province from 2015 to 2018. Serotypes and drug sensitivity of Salmonella strains were analyzed. The annual change in drug resistance was analyzed by Chi-square test and all data were analyzed retrospectively. Results:The detection rate of non-typhoid Salmonella in fecal samples was 8.73% (371/4 250). The highest detection rate was in the 0-1 age group (51.75%) and the peak season for Salmonella infection was from May to October. The most common serotype was Salmonella enteritidis (36.93%), followed by 4, 5, 12: i: - Salmonella (14.82%) and Salmonella typhimurium (14.02%). The non-typhoid Salmonella isolates were resistant to ampicillin and sulfamethoxazole with drug resistance rates of more than 80%, but more sensitive to ceftazidime, cefepime and cefoxitin. There were significant differences in drug resistance to cefepime, levofloxacin, ciprofloxacin, amikacin, doxycycline, chloramphenicol and compound neoforman among the strains isolated in different years ( P<0.05). Multidrug-resistant strains accounted for 86.52%. Conclusions:There was diversity in the serotypes of non-typhoid Salmonella in diarrheal children under five years old in Henan Province. The predominant serotype was Salmonella enteritidis. Drug resistance to common antibiotics was detected in the isolates, and most of them were multidrug-resistant.
Résumé
Objective@#To investigate and analyze the clinical features, epidemiologic information and pathogenic characteristics of a rabies patient.@*Methods@#Clinical data of the patient(boy) was collected and epidemiological survey was conducted, fluorescence quantitative reverse transcription-polymerase chain reaction (FQRT-PCR) and reverse transcription-polymerase chain reaction (RT-PCR) were used to detect the samples of saliva, cerebrospinal fluid (CSF), skin tissue with hair follicle at the back of the neck for rabies laboratory diagnosis.@*Results@#Early symptoms of the boy were vomiting, diarrhea, fever and irritability, followed by coma and death. The boy had nasal trauma one month ago and the domestic dog died of illness during the same period. He did not accept the rabies post-exposure prophylaxis (PEP). The result of the saliva sample was positive by FQRT-PCR. The predicted segments of the glycoprotein(G), nucleoprotein (N) genes of rabies virus were amplified from the positive saliva sample of the patient by RT-PCR. Compared with rabies virus strains in Henan province, the nucleotide homology and amino acid homology in G gene segment were 96.5%-98.8% and 96.5%-99.2% respectively.@*Conclusions@#The case was diagnosed in laboratory as rabies case. The pathogenic rabies virus strain was endemic in Henan province. The nasal trauma, the dead domestic dog were probably related to the infection of the boy.
Résumé
To study the epidemiology and etiology characteristics of first imported Chikungunya fever case in Henan province, China, 2017. The patient was confirmed by Chikungunya virus (CHIKV) infected as CHIKV ribonucleotide was continuously detected in his serum specimens. BHK-21 cell line was used for virus isolation, the strain was named CHIKV/Henan001/2017. CHIKV/Henan001/2017 belonged to genotype ECSA. The highest ribonucleotide homology sequence of highly conserved region E1 with CHIKV/Henan001/2017 was hk02 strain (99.8%), who was an imported strain to Hong Kong, China, 2016. Epidemiological information and laboratory testing confirmed it was an imported Chikungunya fever case in Henan province, 2017. No secondary case has been reported.
Résumé
Objective To investigate the distribution and etiological characteristics of Yersinia en-terocolitica in Henan province between 2011 and 2017 and to analyze the homology among pathogenic strains. Methods A total of 12728 samples, including stool specimens from patients with diarrhea and domestic animals, flies, and smear specimens from raw and cooked meat products, were collected. Cold enrichment method was used to isolate Yersinia enterocolitica. The isolated strains were analyzed by biochemical identifi-cation, biotyping, serotyping and virulence gene detection with PCR. Pulsed-field gel electrophoresis ( PFGE) was performed for molecular typing of pathogenic strains. Results There were 390 strains of Yersinia enterocolitica isolated from the 12728 specimens with a detection rate of 3. 06%, including 13 hu-man strains and 377 animal strains. Most of the strains were isolated from pig and chicken feces and both ac-counted for 25. 13% (98/390). The predominant biotype was 1A and the serotypes of the strains were main-ly O : 5 and O : 8. Results of the virulence gene analysis showed that 21 strains of O : 3 serotype were path-ogenic, including one human strain and 20 pig strains. After NotⅠdigestion, these pathogenic strains were divided into three band types with a band similarity of 94%-100%. Conclusions Yersinia enterocolitica ex-isted in both human population and many kinds of animals in Henan province. Pig was the main host of path-ogenic strains and there was a high homology among these strains.
Résumé
Objective To analyze the VP1 sequences of coxsackievirus A16(CA16) causing neu-rologic complications. Methods Clinical samples and epidemiological information were collected from pa-tients with viral encephalitis. Coxsackievirus A16 in these samples were first detected with real time RT-PCR and then isolated. RT-PCR was performed to amplify VP1 sequences and the amplified products were se-quenced. DNAStar 5.0 and Mega 5 were used for sequence analysis. All data was analyzed with SPSS statis-tical software. Results Fifteen samples were collected from 12 patients with hand, foot and mouth disease (HFMD) complicated by neurologic complications. Eight patients had the symptoms of fever, skin rash, signs of meningeal irritation and neck rigidity. No typical cluster was associated with clinical features or the time of onset. Both pharyngeal/anal swab and serum samples were collected from three patients (patient′s number:01111,01169 and 01130). The two samples collected from both 01111 and 01130 patients shared 100% similarity in nucleotide and amino acid based on VP1 sequences,while those from 01169 patient dif-fered in only one base. The 15 CA16 isolates were highly similar in VP1 gene, sharing 94.5%-100% ho-mology in nucleotide sequences and 98.0%-100% homology in amino acid sequences. These 15 isolates showed 68.5%-70.5% identities in nucleotide sequences and 90.5%-91.9% identities in amino acid se-quences with the CA16 prototype strain G10. Phylogenetic analysis revealed that based upon VP1 sequences, all of the 15 CA16 isolates grouped into genotype B subtype 1b (B1b), which was further classified into three clusters. Conclusion All of the 15 CA16 isolates causing neurologic complications belonged to B1b sub-genotype. Understanding the molecular epidemiology of CA16 would be essential for controlling morbidi-ty rates of HFMD and vaccine research.
Résumé
Objective To monitor the environmental contamination with avian influenza virus (AIV) in Henan Province. Methods Environmental samples were collected every month from seven moni-toring sites in Henan from 2013 to 2017. Real-time RT-PCR method was performed to detect the nucleic acid of influenza A (Flu A), H5, H7 and H9 viruses in poultry environmental samples. Results A total of 2538 environmental samples were collected and 202 (7. 96% ) of them were positive for Flu A nucleic acid, including 16 positive for H5 (0. 63% ), eight positive for H7 (0. 32% ) and 161 positive for H9 (6. 34% ). The detection rate of Flu A increased dramatically from 2013 to 2017 except for a small fluctuation in 2015. However, H7 subtype AIV was detected only in 2015 and 2017. The highest detection rate of AIV was in February, followed by that in January. Among different environments, the highest detection rate of Flu A was in live poultry market, which was 13. 69% , followed by that in poultry slaughtering plant (2. 58% ) and poultry farm (0. 58% ). The detection rates of Flu A in swab samples of poultry plucker and cutting board, stool specimens and poultry drinking water were 28. 57% , 13. 76% , 5. 70% and 5. 26% , respectively.Conclusion Contamination of H5 / H7 / H9 AIV did exist in poultry environment in Henan and was getting worse. Increasingly diversified sources and sale channels were the main causes of serious contamination of AIV. In order to effectively prevent and control human infection with AIV, live poultry in areas where human infection with AIV was confirmed should be blocked and banned to be sold to others areas.
Résumé
Objective@#To confirm the laboratory diagnosis of dengue bordline cases reported in Henan Province and trace its origin from molecular level in 2017.@*Methods@#The study samples were blood samples (3-5 ml), which came from 8 suspected cases of dengue fever reported in the 2017 direct reporting system of Henan provincial infectious disease monitoring network. Meanwhile, case investigation was conducted according to National dengue fever surveillance programme. Serum were separated from blood samples and tested for Dengue NS1 antigen, IgM & IgG antibodies, and dengue RNA. According to dengue diagnosis criteria, confirmed cases were identified by testing results. Samples carried dengue RNA performed for real-time PCR genotyping and amplification of E gene. Then, the amplicons were sequenced and homological and phylogenetic analyses were constructed.@*Results@#8 serum samples of suspected dengue cases were collected in Henan Province, 2017. Six of them were diagnosed as dengue confirmed cases. All the dengue confirmed cases belonged to outside imported cases, 5 of them were positive by dengue RNA testing. Genotyping results showed there were 1 DENV1 case, 2 DENV2 cases and 2 DENV3 cases. A DENV2 case and a DENV3 case of this study were traced its origin successfully. The sequence of Pakistan imported DENV2 case belongs to cosmopolitan genotype, which was the most consistent with Pakistan's DENV2 KJ010186 in 2013 (identity 99.0%). The sequence of Malaysia imported DENV3 case belongs to genotype I, which was the most consistent with Singapore's DENV3 KX224276 in 2014(identity 99.0%).@*Conclusion@#The laboratory diagnosis and molecular traceability of dengue cases in Henan Province in 2017 confirmed that all cases were imported and did not cause local epidemics.
Résumé
Objective To evaluate different detection methods in the diagnosis of severe fever with thrombocytopenia syndrome (SFTS), and find the most quick and accurate one for the identification of new bunyavirus infection. Methods Real-time PCR and ELISA-IgM were used to detect serum samples of 158 patients with acute phase of SFTS, which were collected from the special monitoring system of SFTS in Henan Province in 2014. IgM and IgG antibodies were detected by ELISA in 109 acute and convalescent paired serum specimens. The differences of the positive rates were compared between the three methods, and the influence of the collected interval time on the detection results was analyzed. Results For 158 acute phase serum samples of SFTS patients, the positive rate detected by real-time PCR (76.58%) was higher than that of ELISA-IgM (47.47%), and the difference was statistically significant (χ2=34.13, P 0.05). In both the acute phase and convalescent phase, the positive rate of IgM was higher than that of IgG, and the difference was statistically significant (χ2=41.68 and 6.25, P<0.05). With the extension of collected interral time, the positive rates of IgM and IgG antibodies were both increased ( Z=6.42 and 10.08, P < 0.05). Conclusion Real-time PCR is the most sensitive method for the early diagnosis of the SFTS. ELISA-IgG is suitable for the detection of SFTS at recovery period. ELISA-IgM can be used as an assistant method to guide clinical diagnosis.