Humans ; Severe Fever with Thrombocytopenia Syndrome ; Phlebovirus

Objective: To understand the epidemiological characteristics of tick-borne infectious diseases (TBID) and the risk factors of severe illness and death in Hubei Province from 2016 to 2021. Methods: Based on the incidence data of fever with thrombocytopenia syndrome (SFTS), tsutsugamushi disease, typhus and other TBID reported during 2016-2021, the epidemiological analysis was conducted. Field investigation results of TBID in areas with high incidence in 2021, logistic regression analysis of population characteristics, epidemiological history and other factors were used to explore the risk factors of severe and fatal cases. In the field vector investigation, free ticks and surface ticks of the host animals in the cases' home and surrounding grassland were monitored and detected. Results: A total of 3 826 TBID cases were reported in Hubei from 2016 to 2021, of which 71.30% (2 728/3 826) were SFTS, 13.04% (499/3 826) were tsutsugamushi disease and 15.66% (599/3 826) were typhus. A total of 44 cases died in 6 years; the fatality rate was 1.15% (44/3 826). In the peak seasons of incidence from May to July, the cases in people engaged in agriculture related work accounted for 84.61% (3 237/3 826). The incidence rate in women was higher than that in men, and the cases aged ≥50 years accounted for 81.02% of the total (3 100/3 826), and the incidence rate increased with age (P<0.001). The TBID cases were distributed in 86 counties and districts in 16 prefectures (municipality). The incidence rates of different areas had significant differences (P<0.05), and there was a certain spatial-temporal clustering and expasion. Bovis microplus and Haemaphysalis longicornis were captured in the field, and the positive rates in host animals and grassland ticks were 10.94% (7/64) and 40.00% (2/5), respectively. Univariate logistic regression analysis results showed that age ≥50 years and leukocyte <2.0×10⁹/L were risk factors for severe illness and death. Conclusions: The TBID reported in Hubei were mainly SFTS, tsutsugamushi disease and typhus. In order to reduce the incidence of TBID, it is necessary to strengthen the prevention and control in women aged ≥50 years and reduce field exposure and tick bites during the epidemic period.
Animals ; Female ; Typhus, Epidemic Louse-Borne ; Scrub Typhus/epidemiology* ; Severe Fever with Thrombocytopenia Syndrome ; Ticks ; Communicable Diseases ; Phlebovirus ; China/epidemiology* ; Tick-Borne Diseases/epidemiology*

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.
Humans ; Severe Fever with Thrombocytopenia Syndrome/epidemiology* ; Bunyaviridae Infections/epidemiology* ; Thrombocytopenia/complications* ; Phlebovirus/genetics* ; Disease Outbreaks ; China/epidemiology*

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.
Humans ; Severe Fever with Thrombocytopenia Syndrome/epidemiology* ; Bunyaviridae Infections/epidemiology* ; Thrombocytopenia/complications* ; Phlebovirus/genetics* ; Disease Outbreaks ; China/epidemiology*

Animals ; Biological Assay ; Nucleic Acid Amplification Techniques ; Phlebovirus/isolation & purification* ; Psychodidae/virology* ; Recombinases/metabolism* ; Reverse Transcription

Objective: To study the molecular epidemiological characteristics and genotypes of hantavirus carried by rodents in Shenzhen. Methods: Rodents were captured, and their lung samples were collected and grinded for RNA extraction. The hantavirus positive samples were classified by real-time fluorescence PCR. Rat lung nucleic acid samples were selected to amplify the nucleotide sequences of partial M fragments (G2 segment) and S fragments by reverse transcription-nested polymerase chain reaction (RT-nested PCR). The PCR products were then sequenced and homology and phylogenetic tree analyses were conducted. Results: A total of 200 rodents were captured, including 189 Rattus norvegicus, 9 Rattus flavipectus and 2 Mus musculus. The positive rate of hantavirus was 21.0% (42/200), all of the isolates were seoul virus (SEOV) strains. The positive rate of hantavirus in Bao'an district was highest (45.7%), and the difference in detection rate among districts were significant (χ²=25.60,P<0.05). A total of 25 G2 segment sequences and S fragment sequences of SEOV were obtained by virus gene sequencing, and their nucleotide homology was 95.3%-100.0% and 97.6%-100.0%, respectively. Compared with other reference sequences of S2 subtype, the nucleotide homology between the sample sequence and the reference sequence from Guangzhou was high. Analysis on nucleotide homology and phylogenetic tree showed that hantavirus carried by the rodents captured in Shenzhen belonged to SEOV S2 subtype. Analysis on amino acid variation sites revealed that there was a variation in the nucleocapsid protein encoded by S gene from Alanine to Threonine at the 973 position of BA-111. Conclusion: Hantavirus carried by rodents in Shenzhen belongs to S2 subtype of Seoul virus, which have little variation compared with the hantavirus strains obtained in other years in Shenzhen and surrounding provinces.
Mice ; Rats ; Animals ; Orthohantavirus/genetics* ; Rodentia ; Phylogeny ; Hantavirus Infections/veterinary* ; Communicable Diseases ; Nucleotides ; Real-Time Polymerase Chain Reaction

The Schmallenberg virus (SBV) is an orthobunyavirus that causes abortions, stillbirths, and congenital defects in pregnant sheep and cattle. Inactivated or live attenuated vaccines have been developed in endemic countries, but there is still interest in the development of SBV vaccines that would allow Differentiating Infected from Vaccinated Animals (DIVA). Therefore, an attempt was made to develop novel DIVA-compatible SBV vaccines using SBV glycoproteins expressed in baculovirus. All vaccines and phosphate buffered saline (PBS) controls were prepared with adjuvant and administered subcutaneously to cattle at 6 month of age. The first trial included 2 groups of animals vaccinated with either carboxyl-terminus glycoprotein (Gc) or PBS and boosted after 2 weeks. In the second trial, 3 groups of cattle were administered either Gc, Gc and amino-terminus glycoprotein (Gn), or PBS with a booster vaccination after 3 weeks. The animals were challenged with SBV 9 days after the booster vaccination in the first study, and 3 weeks after the booster vaccination in the second study. Using a SBV Gc-specific enzyme-linked immunosorbent assay, antibodies were first detected in serum samples 14 days after the first vaccination in both trials, and peaked on days 7 and 9 after the booster in the first and second trials, respectively. Low titers of neutralizing antibodies were detected in serum from only 3/6 and 2/4 animals in the first and second trial, respectively, at 14 days after the first vaccination. The titers increased 2 to 3-fold after the booster vaccination. SBV-specific RNA was detected in the serum and selective tissues in all animals after SBV challenge independent of vaccination status. The SBV candidate vaccines neither prevented viremia nor conferred protection against SBV infection.
Animals ; Antibodies ; Antibodies, Neutralizing ; Baculoviridae ; Cattle ; Congenital Abnormalities ; Enzyme-Linked Immunosorbent Assay ; Glycoproteins ; Orthobunyavirus ; RNA ; Sheep ; Stillbirth ; Vaccination ; Vaccines ; Vaccines, Attenuated ; Vaccines, Subunit ; Viremia

In February 2019, the order Bunyavirales, previously family Bunyaviridae, was amended by new order of 10 families including Hantaviridae family, and now accepted by the International Committee on Taxonomy of Viruses (ICTV). Hantaviridae is now a family of the order Bunyavirales, and the prototype virus species is Hantaan orthohantavirus. The family Hantaviridae is divided into four subfamilies including Mammantavirinae, Repantavirinae, Actantavirinae and Agantavirinae. The subfamily Mammantavirinae is divided into four genera including Orthohantavirus, Loanvirus, Mobatvirus and Thottimvirus. The four Hantavirus species have been found in Korea including three Orthohantaviruses (Hantaan orthohantavirus, Seoul orthohantavirus and Jeju orthohantavirus) and one Thottimvirus (Imjin thottimvirus).
Bunyaviridae ; Classification ; Hantaan virus ; Hantavirus ; Humans ; Korea ; Seoul ; Virology

OBJECTIVES: Jeju Province is well known as the region showing the highest incidence of severe fever with thrombocytopenia syndrome (SFTS) in South Korea. The aim of this study was to evaluate the epidemiological and clinical characteristics of SFTS patients in Jeju Province. METHODS: The primary data for this study were obtained from the Integrated Diseases and Health Control System of the Korea Centers for Disease Control and Prevention (KCDCIS). The selection criteria were confirmed cases of SFTS with a residence listed in Jeju Province at the time of diagnosis, reported to the KCDCIS between July 16, 2014 and November 30, 2018. RESULTS: Of 55 confirmed cases of SFTS, the case fatality rate was 10.9% (95% confidence interval [CI], 4.1 to 22.2). The most common presenting symptoms at diagnosis of severe fever, myalgia, and diarrhea had incidences of 83.6% (95% Cl, 71.2 to 92.2), 45.5% (95% Cl, 32.0 to 59.5), and 40.0% (95% CI, 27.0 to 54.1), respectively. CONCLUSIONS: Compared to SFTS patients nationwide in 2013-2015, the subjects of this study exhibited a lower case fatality rate and had a lower incidence of severe fever, myalgia, and confusion.
Bunyaviridae Infections ; Centers for Disease Control and Prevention (U.S.) ; Diagnosis ; Diarrhea ; Fever ; Humans ; Incidence ; Korea ; Mortality ; Myalgia ; Patient Selection ; Thrombocytopenia ; Tick-Borne Diseases

The Ministry of Food and Drug Safety of Korea made an official announcement in March 2018 that the total number of inoculations of Hantaan virus vaccine (Hantavax®) would change from 3 to 4. Some aspects of this decision remain controversial. Based on the characteristics of Hantaan virus (HTNV) and its role in the pathogenesis of hemorrhagic fever with renal syndrome, it might be difficult to develop an effective and safe HTNV vaccine through the isolate-inactivate-inject paradigm. With the development of high-throughput ‘omics’ technologies in the 21st century, vaccinomics has been introduced. While the goal of vaccinomics is to develop equations to describe and predict the immune response, it could also serve as a tool for developing new vaccine candidates and individualized approaches to vaccinology. Thus, the possibility of applying the innovative field of vaccinomics to develop a more effective and safer HTNV vaccine should be considered.
Hantaan virus ; Hemorrhagic Fever with Renal Syndrome ; Humans ; Immunogenetics ; Korea ; Precision Medicine ; Vaccines ; Vaccines, Synthetic