Genus Phlebovirus is single negative-strand RNA virus, and belongs to family bunyaviridae. Its genomes have three segments including L, M and S encoding RNA-dependent RNA polymerase, envelope glycoprotein and nucleoprotein respectively. Phlebovirus is arbovirus and can be disseminated by arthropod. More than 70 types of Phlebovirus so far have been reported, and 68 known serotypes are divided into groups Sandfly fever and Uukuniemi, of which a few members are closely related to human diseases. In addition, new emerging viruses of genus Phlebovirus are discovered recently. In this review, the latest research progress in molecular characteristics, epidemiology, diagnosis, treatment and emerging viruses of Phlebovirus is summarized.
Animals ; Humans ; Phlebotomus Fever ; diagnosis ; epidemiology ; therapy ; virology ; Phlebovirus ; classification ; genetics ; isolation & purification ; physiology

No abstract available.
Animals ; Humans ; Insect Bites and Stings/virology ; Phlebotomus Fever/*etiology/prevention & control/transmission ; Phlebovirus/isolation & purification/physiology ; Ticks/*virology

Larvae, nymphs, and adult stages of 3 species of ixodid ticks were collected by tick drag methods in Seoul during June-October 2013, and their infection status with severe fever with thrombocytopenia syndrome (SFTS) virus was examined using RT-PCR. During the period, 732 Haemaphysalis longicornis, 62 Haemaphysalis flava, and 2 Ixodes nipponensis specimens were collected. Among the specimens of H. longicornis, the number of female adults, male adults, nymphs, and larvae were 53, 11, 240, and 446, respectively. Ticks were grouped into 63 pools according to the collection site, species, and developmental stage, and assayed for SFTS virus. None of the pools of ticks were found to be positive for SFTS virus gene.
Animals ; Female ; Fever/virology ; Humans ; Ixodidae/*classification/*virology ; Larva/pathogenicity ; Male ; Phlebotomus Fever/virology ; Phlebovirus/*isolation & purification ; Republic of Korea ; Thrombocytopenia/virology ; Tick Infestations/*virology

This article aimed to study the antigenicity of nucleocapsid proteins (NPs) in six pathogenic phleboviruses and to provide theoretical evidence for the development of serological diagnostic reagents. NPs of six pathogenic phleboviruses were expressed and purified using a prokaryotic expression system and rabbits were immunized with individual recombinant NPs. Cross-reactions among NPs and rabbit sera were determined by both indirect ELISA and Western blotting analyses, and the sera titer was determined by indirect ELISA. Furthermore, sera from SFTS patients were also detected by each recombinant NP as a coating antigen using indirect ELISA. The cross-reactions and the sera titer were subsequently determined. Both the concentration and purity of recombinant NPs of six pathogenic phleboviruses met the standards for immunization and detection. The results of indirect ELISA and Western blotting showed that each anti-phlebovirus NP rabbit immune serum had potential serological cross-reactivity with the other five virus NP antigens. Furthermore, the sera from SFTS patients also had cross-reactivity with the other five NP antigens to a certain extent. Our preliminary study evaluated the antigenicity and immune reactivity of six pathogenic phleboviruses NPs and laid the foundation for the development of diagnostic reagents.
Animals ; Antibodies, Viral ; immunology ; Antigens, Viral ; genetics ; immunology ; Cross Reactions ; Humans ; Nucleocapsid Proteins ; genetics ; immunology ; Phlebotomus Fever ; diagnosis ; immunology ; virology ; Phlebovirus ; classification ; genetics ; immunology ; isolation & purification ; Rabbits

The severe fever with thrombocytopenia syndrome virus (SFTSV) is a new member in the genus Phlebovirus of the family Bunyaviridae identified in China. The SFTSV is also the causative pathogen of an emerging infectious disease: severe fever with thrombocytopenia syndrome. Using immunofluorescent staining and confocal microscopy, the intracellular distribution of nucleocapsid protein (NP) in SFTSV-infected THP-1 cells was investigated with serial doses of SFTSV at different times after infection. Transmission electron microscopy was used to observe the ultrafine intracellular structure of SFTSV-infected THP-1 cells at different times after infection. SFTSV NP could form intracellular inclusion bodies in infected THP-1 cells. The association between NP-formed inclusion bodies and virus production was analyzed: the size of the inclusion body formed 3 days after infection was correlated with the viral load in supernatants collected 7 days after infection. These findings suggest that the inclusion bodies formed in SFTSV-infected THP-1 cells could be where the SFTSV uses host-cell proteins and intracellular organelles to produce new viral particles.
Cell Line ; China ; Humans ; Inclusion Bodies, Viral ; ultrastructure ; virology ; Macrophages ; ultrastructure ; virology ; Phlebotomus Fever ; virology ; Phlebovirus ; genetics ; physiology ; ultrastructure ; Thrombocytopenia ; virology

OBJECTIVETo analyze the data of surveillance on severe fever with thrombocytopenia syndrome (SFTS), from 2011 to 2012 in China.

METHODSDescriptive methods were conducted to analyze the surveillance data from 2011 to 2012 which were collected from the internet-based National Notifiable Disease Reporting System.

RESULTSFrom 2011 to 2012, a total of 1229 SFTS cases and 107 deaths were reported in China with the average annual incidence rate of 0. 046/100 000 and case fatality rate of 8.7%. Compared to 2011, morbidity of 2012 has increased by 23.5% and mortality has decreased by 32%. 16 provinces reported SFTS cases. More cases occurred in spring and summer seasons,with the peak in May to July, during this period, 69% of the total cases were reported. The ages of the patients ranged from 1 to 85 years, 44.2% of total case was 55 to 70 years old, there were no differences in sex. Of all the cases 86. 8% was farmer.

CONCLUSIONSevere fever with thrombocytopenia syndrome in widely distributed in China, especially in the central and eastern regions, the incidence has obvious seasonal. Surveillance and immigration quarantine should be strengthened.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Child ; Child, Preschool ; China ; epidemiology ; Epidemics ; Humans ; Infant ; Male ; Middle Aged ; Phlebotomus Fever ; epidemiology ; mortality ; virology ; Phlebovirus ; classification ; genetics ; isolation & purification ; Sentinel Surveillance ; Young Adult

An emerging infectious disease was identified as severe fever with thrombocytopenia syndrome (SFTS) in central China since late March 2009. We found the patients with SFTS had severe clinical symptoms, and progressed rapidly to multiple organ dysfunction syndrome (MODS) with high fatality rate of 25%-30%. The aim of this study was to assess the significance of risk factors predicting the development of MODS and death in SFTS patients. Consecutive SFTS admissions between May 2009 and September 2011 were analyzed for parameters of organ function during hospitalization using Marshall scoring system for MODS, and platelet counts were recorded on admission and at 24, 48, 72 h and one week after admission. We investigated the kinetics of organ failures and analyzed the association between age, platelet count and development of MODS or death. A total of 92 SFTS patients were enrolled in this study. Among them, 32 patients with dysfunction of over 4 organs were identified, 45% of them died within 72 h, 72% died within 5 days, and 76% died within 7 days after admission. We also found cumulative Marshall score was significantly higher in death patients (11.76±2.05) than in survival patients (4.22±1.98) (P<0.001). In addition, SFTS patients had older age and lower platelet counts in MODS and death groups. Furthermore, we also observed that there was a close correlation between platelet count on admission and Marshall score (P<0.001). High Marshall score, advanced age and lower platelet counts were the main risk factors for the development of MODS, and those factors could predict mortality in SFTS patients, suggesting prompt treatment and close monitoring of severe complications, especially MODS, are of great importance in saving patients' lives.
Adolescent ; Adult ; Aged ; China ; Comorbidity ; Female ; Hospital Mortality ; Humans ; Length of Stay ; statistics & numerical data ; Male ; Middle Aged ; Multiple Organ Failure ; mortality ; Phlebotomus Fever ; mortality ; Risk Assessment ; Statistics as Topic ; Survival Rate ; Syndrome ; Thrombocytopenia ; mortality ; Young Adult