[The epidemiology and pathogeny investigation of two clusters of severe fever with thrombocytopenia syndrome disease outbreaking in Henan Province, 2022].

To investigate two clusters of severe fever with thrombocytopenia syndrome virus (SFTSV) in Xinyang City, Henan Province, in 2022, and analyze their causes, transmission route, risk factors, and the characteristics of virus genetic variation. Case search and case investigation were carried out according to the case definition. Blood samples from cases, family members and neighbors and samples of biological vectors were collected for RT-PCR to detect SFTSV. The whole genome sequencing and bioinformatics analysis were performed on the collected positive samples. A total of two clustered outbreaks occurred, involving two initial cases and ten secondary cases, all of which were family recurrent cases. Among them, nine secondary cases had close contact with the blood of the initial case, and it was determined that close contact with blood was the main risk factor for the two clustered outbreaks. After genome sequencing analysis, we found that the SFTSV genotype in two cases was type A, which was closely related to previous endemic strains in Xinyang. The nucleotide sequence of the SFTSV in the case was highly homologous, with a total of nine amino acid mutation sites in the coding region. It was not ruled out that its mutation sites might have an impact on the outbreak of the epidemic.

[Analysis of epidemiological characteristics of bacillary dysentery with multiple-onset in Henan Province from 2005 to 2020].

Objective: To understand the epidemiological characteristics of bacillary dysentery with multiple-onset in Henan province from 2005 to 2020. Methods: The reported cases of bacillary dysentery (including confirmed cases and clinically diagnosed cases) in Henan Province from January 2005 to December 2020 were collected through China's National Disease Supervision Information Management System. The main information included gender, age, home address, date of onset and date of diagnosis. The interval between two episodes of the same case was more than 15 days, which was judged as two episodes. The incidence characteristics of bacillary dysentery patients with two or more cases in Henan Province from 2005 to 2020 were analyzed, and the regional distribution map of cases was drawn using ArcGIS software. Results: From 2005 to 2020, a total of 250 430 cases of bacillary dysentery were reported in Henan Province, with a cumulative incidence rate of 228.66/100 000. There were 2 342 cases with two or more attacks. The incidence of recurrent cases of bacillary dysentery increased year by year (χ2trend=2 932.28, P<0.001). There was no significant difference in the incidence of two or more cases of different sexes (χ2=0.39, P=0.540). There was significant difference in the incidence among different age groups (χ2=438.40, P<0.001). The incidence of two or more cases in the 60-69 age group was relatively high (1.70%). The shortest time interval between the onset of the disease was 16 days, and the longest was 5 579 days, with M (Q1, Q3) about 428 (237, 843) days. Compared with healthy people, those with a history of bacterial diseases had a higher risk of developing bacillary dysentery (RR: 4.12, 95%CI: 3.95‒4.29). Conclusion: The proportion of patients with multiple-onset shows an increasing trend, and there is an age difference.

[Human enterovirus infection status and clinical characteristics of 274 patients with viral encephalitis in Henan Province, 2011-2012].

Objective: To investigate human enterovirus (HEV) infection and clinical characteristics of viral encephalitis patients in Pingdingshan, Henan Province. Methods: Cerebrospinal fluid specimens and epidemiological information were collected from 274 viral encephalitis patients in the departments of pediatrics and neurology in hospitals in Pingdingshan, Henan Province, from April 2011 to August 2012. Patients with bacterial infections were excluded from the study. Demographic information was collected by questionnaires and clinical information was mainly obtained from hospital examinations. Viral RNA was extracted using magnetic bead extraction. Real-time RT-PCR was then performed for HEV, CV-A16, and EV-A71 testing. SPSS statistical software was statistical analyses. Significant differences were determined using the chi-squared test (P<0.05). Results: Among 274 cases of viral encephalitis, 180 cases (65.7%) were male and 94 cases were female (34.3%). The median age was 2.17 years. Approximately 61.3% (168) of patients were younger than 3 years of age. A total of 107 (39.1%), 2 (0.7%), and 42 (15.3%) cases were positive for HEV, CV-A16, and EV-A71, respectively. Eleven patients were younger than 6 months of age and one patient was co-infected with HEV and EV-A71. In the<3, 3-5, 6-15, and>15 years old age groups, HEV infections comprised 31.5% (53/168), 52.9% (18/34), 53.0% (35/66), and 16.7% (1/6) (χ(2)=13.10, P=0.003), respectively. The EV-A71 infection rates were 17.9% (30/168), 23.5% (8/34), 6.1% (4/66), and 0 (χ(2)=8.04, P=0.045), respectively. The other enterovirus (OEV) infection rates were 12.5% (21/168), 29.4% (10/34), 48.5% (32/66), and 16.7% (1/6) (χ(2)=35.19, P<0.001), respectively. The rate of vomiting in OEV and EV-A71 infected patients was 73% (44/60) and 26% (11/42), respectively, while the frequency of skin rash in OEV and EV-A71 infected patients was 32% (19/60) and 79% (33/42), respectively. Approximately 95% (99/104) of patients infected with HEV had a fever, and the breathing rhythm change rate was 19% (20/104), which was lower than that of patients without HEV infection (36.8% (60/163)) (χ(2)=9.35, P=0.002). Conclusion: In Pingdingshan, HEV was a major causative agent of viral encephalitis and the rate of OEV infection was high, especially in children aged 3-15 years old. Fever was a common clinical symptom of patients infected with HEV. Patients infected with OEV primarily exhibited vomiting symptoms and EV-A71 infected patients showed skin rash.

[Surveillance for sever fever with thrombocytopenia syndrome in Henan province, 2017-2020].

Objective: To analyze the epidemiological and etiological characteristics of sever fever with thrombocytopenia syndrome (SFTS) cases in Henan province during 2017-2020. Methods: Descriptive epidemiology method was used to analyze the characteristics of SFTS cases in Henan during 2017-2020. Patients' sera in acute phase were collected and tested using real-time fluorescence RT-PCR. The S segment complete sequences of the isolated sever fever with thrombocytopenia syndrome virus (SFTSV) strains were amplified and homology analysis was performed to construct the phylogenetic tree. Results: A total of 1 767 SFTS cases, including 1 000 suspected cases and 767 confirmed cases, were reported in Henan during this period, and 11 cases, including 3 suspected cases and 8 confirmed cases died, the case fatality rate was 0.62% (11/1 767). The incidence decreased year by year. The cases were distributed in 28 counties of 6 cities, and 1 681 cases were reported in Xinyang, accounting for 95.13% (1 681/1 767) of the total. The cases mainly occurred from April to October, accounting for 96.10% (1 698/1 767) of the total. The incidence in males (0.38/100 000) was significantly lower than that in females (0.54/100 000) (χ2=54.855, P<0.001). Up to 93.44% (1 651/1 767) of the cases were aged between 40 and 84 years. Farmers accounted for 96.10% (1 698/1 767) of the total cases. One family cluster outbreak occurred in 4 years. A total of 1 110 samples were detected by Henan CDC, in which 435 were SFTS virus positive with an average positive rate of 39.19% (435/1 110). The differences in positive rates of SFTS virus among different years were significant (χ2=25.405, P<0.001). The sequence homology of complete S segment of the 39 SFTS virus strains ranged from 94.76% to 99.82%. The genetic evolution analysis on the complete S segment of the 39 SFTS virus strains showed that 34 strains belonged to genotype A, 2 strains belonged to genotype B, and 3 strains belonged to genotype D. Conclusions: The incidence of SFTS in Henan was sporadic, and decreased year by year. SFTS had obvious regional and seasonal characteristics, and the area affected by SFTS expanded. The incidence of SFTS was high in elderly female farmers, and the positive rate of SFTS virus varied greatly in different years. The main type of SFTS virus in Henan was genotype A, but the etiological surveillance is still needed.

[Characteristics of spatiotemporal distribution on severe fever with thrombocytopenia syndrome in Henan province].

Objective: To explore the characteristics regarding temporal, spatial and spatiotemporal distribution on severe fever with thrombocytopenia syndrome (SFTS) in Henan province. Methods: Surveillance data related to SFTS was collected in Henan province, from year 2014 to 2016. Descriptive method was used to analyze the distribution of SFTS. 1.7.0 software related to the Public health geographic information system (PHGIS), was applied to draw the spatial distribution map of SFTS. Chi-square test was used to compare the different incidence rates. Results: A total of 2 781 SFTS cases, including 34 deaths, were reported in Henan province from 2014 to 2016, with an average annual fatality rate as 1.22%. There were statistically significant differences for the incidence rates of SFTS between different years (P<0.01). Cases were mainly concentrated from April to October, which accounted for 96.66% of the total number, with the incidence peak seen in May. Incidence rates of SFTS in spring, summer, autumn were higher than that in winter. The cases were scattering around in 26 counties of 8 cities. Xinyang city reported 2 714 cases, accounting for 97.59% of the total number of cases in the province. The average annual incidence rate in Xinyang city was 17.22 per 100 000, much higher than that for the whole Henan province (0.98 per 100 000), with statistically significant difference (P<0.01). Six counties reported having death cases, that accounted for 23.08% of the total number of counties, reported to have death cases. Two kinds of incidence patterns of SFTS were noticed in Henan province, with aggregation in some local regions or sporadic in individual counties. The number of counties with reporting cases increased annually. The epidemic area was expanding and gradually spreading from south to north areas of the province. Conclusions: SFTS was characterized with both temporal and spatial clusters in Henan province. Effective prevention and control measures should be made in accordance with the spatiotemporal distribution and the trend on SFTS.