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

We report the first case of severe fever with thrombocytopenia syndrome (SFTS) and a spontaneous acute subdural hematoma (SDH) in Korea. A 79-year-old male presented with fever and thrombocytopenia. On the third day of hospitalization, his mental changed from drowsy to semi-coma. Brain computed tomography indicated an acute subdural hemorrhage on the right convexity. He was given early decompressive craniectomy, but did not survive. Real-time reverse transcription polymerase chain reaction analysis of a blood sample indicated the presence of SFTS virus (SFTSV). This is the first reported case with intracranial hemorrhage and SFTS. This case report describes our treatment of a patient with acute SDH and an infection from a tick-borne species of Bunyaviridae.
Aged ; Brain ; Bunyaviridae ; Decompressive Craniectomy ; Fever* ; Hematoma, Subdural* ; Hematoma, Subdural, Acute ; Hospitalization ; Humans ; Intracranial Hemorrhages ; Korea ; Male ; Orthobunyavirus ; Polymerase Chain Reaction ; Reverse Transcription ; Thrombocytopenia* ; Ticks*

BACKGROUND/AIMS: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease caused by severe fever with thrombocytopenia syndrome virus (SFTSV), a novel bunyavirus. As yet, there is no effective antiviral therapy for SFTS. Ribavirin is a broad-spectrum antiviral agent, which has been tried for treatment of SFTS. In this study, antiviral activity of ribavirin against SFTSV has been investigated. METHODS: Vero cell-grown SFTSV strain Gangwon/Korea/2012 was treated with ribavirin at various concentrations. Antiviral activity of ribavirin was evaluated by inhibition of the SFTSV cytopathic effect in Vero cells and quantification of viral RNA load in culture supernatant using one-step real-time reverse transcription polymerase chain reaction. Cytotoxicity of ribavirin was determined by a tetrazolium-based colorimetric method. RESULTS: Ribavirin reduced SFTSV titers in a dose-dependent manner, with a half-maximal inhibitory concentration ranged from 3.69 to 8.72 μg/mL. Cytopathic effects were reduced as ribavirin concentration increased. No significant cytotoxicity was detected at ribavirin concentrations of ≤ 31.3 μg/mL. CONCLUSIONS: Ribavirin exhibited inhibitory activity against SFTSV replication in vitro, which suggests that ribavirin can be used as a potential antiviral agent for SFTS.
Antiviral Agents ; Bunyaviridae Infections ; Communicable Diseases, Emerging ; Fever* ; In Vitro Techniques* ; Methods ; Orthobunyavirus ; Phlebovirus ; Polymerase Chain Reaction ; Reverse Transcription ; Ribavirin* ; RNA, Viral ; Thrombocytopenia* ; Vero Cells

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne disease. The primary symptoms associated with SFTS are fever, thrombocytopenia, leukopenia, nausea, and vomiting. Disease progression shows high mortality rate accompanied with multiple organ failure, bleeding tendency, and altered mentality. However, only supportive care has been the basis for the treatment of SFTS. We are reporting two patients who showed central nervous system manifestation, but cured them with ribavirin together with plasma exchange in an early state. The first case is a 60-year-old male, who was admitted to the hospital with a 7-day history of fever, chills, and thrombocytopenia. He was treated with empirical antibiotics; however, he experienced persistent high fever and an altered mentality has occurred. On hospital day 6, the SFTS virus (SFTSV) result from a real-time reverse transcription-polymerase chain reaction (RT-PCR) was confirmed positive. Therefore, ribavirin (30 mg/kg as initial loading dose, 15 mg/kg qid for 4 days and then 7.5 mg/kg qid as maintenance dose) was administered orally for 11 days and plasma exchange was performed for 5 days. The clinical outcome has improved. The second case is a 48-year-old male, who was admitted to the hospital with a 10-day history of fever, chills, myalgia, diarrhea, and thrombocytopenia. He was treated with empirical antibiotics. On hospital day 3, ribavirin (30 mg/kg as initial loading dose, 15 mg/kg qid as maintenance dose) was administered orally for 4 days and plasma exchange was performed for 4 days due to his high fever and altered mentality after a positive SFTSV result from a real-time RT-PCR. The patient had a successful recovery.
Anti-Bacterial Agents ; Central Nervous System ; Chills ; Diarrhea ; Disease Progression ; Fever* ; Hemorrhage ; Humans ; Leukopenia ; Male ; Middle Aged ; Mortality ; Multiple Organ Failure ; Myalgia ; Nausea ; Orthobunyavirus ; Plasma Exchange* ; Plasma* ; Ribavirin* ; Thrombocytopenia* ; Tick-Borne Diseases ; Vomiting

We wished to sequence the full-length genomes of the DHL10M110 strain of the Akabane virus (AKV) isolated from mosquitoes in Yunnan Province, China, in 2010. We also wished to analyze the characteristics of these complete nucleotide sequences. The complete genomic sequence of the DHL10M110 strain from Yunnan Province was obtained by reverse transcription-polymerase chain reaction and direct sequencing. We found that the length of the L, M and S gene nucleotide sequences of the DHL10M110 strain were 6 869-bp, 4 309-bp and 856-bp, respectively, including the open reading frame (ORF) nucleotide sequences of 6 756-bp (L), 4 206-bp (M) and 702-bp (S), encoding 2252, 1402 and 234 amino-acid polyproteins, respectively. Phylogenetic analyses based on L-fragment ORF showed that the DHL10M110 strain had a close relationship with the OBE-1 strain of the AKV from Japan and AKVS-7/SKR/2010 strain of the AKV from South Korea. Phylogenetic analyses based on M- and S-fragment ORF showed that the DHL10M110 strain had a close relationship with the epidemic strains of the AKV from Japan, South Korea and Taiwan, but that the DHL10M110 strain had a lone evolutionary branch. In terms of nucleotide (amino acid) homology, the similarity of L-, M- and S-fragment ORFs of the DHL10M110 strain to the OBE-1 strain from Japan was 92.6% (98%), 88.5% (94%) and 96.4% (99.1%), respectively. When comparing the DHL10M110 strain with the OBE-1 strain, we noted 45, 84, and 2 different sites in the amino acids of L, M and S fragments, respectively. Homology and phylogenetic analyses also suggested that the DHL10M110 strain had a distant relationship with the epidemic strains of the AKV from Kenya and Australia. Also, we confirmed by complete genomic sequence analyses that the DHL10M110 strain was clade-Asia of the AKV. However, differences between the DHL10M110 strain compared with strains from Japan and South Korea were also noted. These results suggest that the DHL10M110 strain harbored relatively stable genetic characteristics and distinct regional features. This is the first time that full-length genomic sequences of the DHL10M110 strain of the AKV in mainland China have been obtained.
Amino Acid Sequence ; Animals ; Base Sequence ; Bunyaviridae Infections ; transmission ; virology ; China ; Culicidae ; virology ; Female ; Genome, Viral ; Humans ; Insect Vectors ; virology ; Male ; Molecular Sequence Data ; Open Reading Frames ; Orthobunyavirus ; classification ; genetics ; isolation & purification ; Phylogeny ; Sequence Alignment ; Viral Proteins ; chemistry ; genetics

Severe fever with thrombocytopenia syndrome (SFTS) is firstly reported in China in 2011. Thereafter it is reported an infectious disease in Japan and Korea. It is caused by bunyavirus, called SFTS virus (SFTSV). The main vector of SFTS is Haemaphysalis longicornis tick. We investigated the distribution and detection of SFTSV in ticks collected from the environment using the dragging method and dry ice fogging method from May to November 2014 in Jeollanam-do, Korea. Sampling was taken from the province Suncheon, Gokseong, Boseong, Goheung where patients have occurred in 2013 and Gurye as control. Among the total 3,048 ticks collected, 3,030 ticks were H. longicornis (99.4%) and 18 were Amblyomma testudinarium. H. longicornis was collected 1,330 ticks in Gokseong, 1,188 ticks in Boseong, 240 ticks in Suncheon, 150 ticks in Goheung and 140 ticks in Gurye. Developmental stages by month of H. longicornis were revealed that nymph (92%) was collected from May to June, adult (30%) and nymph (70%) in July, and 93% of larvae from September to October. These results showed the different dominant stage of ticks according to seasons. However, no SFTSV-specific gene was detected in 3,030 ticks of H. longicornis.
Adult ; China ; Communicable Diseases ; Dry Ice ; Fever* ; Humans ; Japan ; Jeollanam-do* ; Korea* ; Larva ; Methods ; Nymph ; Orthobunyavirus ; Seasons ; Thrombocytopenia* ; Ticks* ; Weather

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne disease caused by the newly discovered SFTS Bunyavirus, and there have been no case reports of SFTS patients presenting with hemophagocytic lymphohistiocytosis (HLH) in the English literature. We report a case of SFTS presenting with HLH in a 73-year-old immunocompetent male farmer. Although the patient had poor prognostic factors for SFTS, such as old age and central nervous system symptoms, he recovered fully with supportive care.
Aged ; Central Nervous System ; Farmers ; Fever* ; Humans ; Lymphohistiocytosis, Hemophagocytic* ; Male ; Orthobunyavirus ; Phlebovirus ; Thrombocytopenia* ; Tick-Borne Diseases

To evaluate the prevalence of mosquito-borne viruses in Manshi and Ruili (Yunnan Province, China), we collected 2 149 mosquitoes (17 species) in August 2010. Virus isolation was undertaken by the cul- ture of baby hamster kidney cells (BHK-21 cells). Two virus-like isolates were obtained: DHL10M117 was isolated from collected in Mangshi; DHL10M110 was obtained from Anopheles vagus collected in Rui- li. Both isolates caused cytopathic effects,illness and death in suckling mice inoculated with these isolates via the intracerebral route. Two positive amplicons, 702-bp from the S segment and 456-bp from the M segment,were obtained using reverse transcription-polymerase chain reaction using primers specific for the Akabane virus (AKV). Phylogenetic analysis suggested that these two virus stains had a distant relation- ship with AKVs from Kenya and Australia,but were genetically close to those from Japan,South Korea, and Taiwan. However,they were separate from other Asian strains and grouped into a small branch. The highest nucleotide and amino-acid sequence identity of the S segment was found with the CY-77 strain from Taiwan (96.6% and 99.6% for DHL10M117 and 96.7% and 100% for DHL10M110,respectively). Com- parison of the M segment showed they shared the highest amino acid identity with CY-77 (99.6% and 100%, respectively), whereas the highest nucleotide identity was found with the Iriki strain from Japan (99.6% and 100%, respectively). Compared with the MP496 strain from Kenya,they displayed lower lev- els of sequence homology, at 69.7% and 70.0% for nucleotide sequences of the two loci,and 91. 0% for a- mino acids. Our results identified that DHL10M117 and DHL10M110 were strains of AKV,and provided molecular biological evidence for the existence of AKV in Yunnan Province. These AKV strains that are circulating in Yunnan Province share a close genetic relationship with strains from the rest of Asia. Culex tritaeniorhynchus and Anopheles vagus may serve as transmission vectors.
Amino Acid Sequence ; Animals ; Anopheles ; virology ; Base Sequence ; Bunyaviridae Infections ; virology ; China ; Cricetinae ; Female ; Humans ; Insect Vectors ; virology ; Male ; Mice ; Orthobunyavirus ; classification ; genetics ; isolation & purification ; physiology ; Phylogeny ; Sequence Homology ; Viral Proteins ; chemistry ; genetics

A real-time RT-PCR (RT-qPCR) assay for the detection of Tahyna virus was developed to monitor Tahyna virus infection in field-collected vector mosquito samples. The targets selected for the assay were S segment sequences encoding the nucleocapsid protein from the Tahyna virus. Primers and probes were selected in conserved regions by aligning genetic sequences from various Tahyna virus strains available from GenBank. The sensitivity of the RT-qPCR approach was compared to that of a standard plaque assay in BHK cells. RT-qPCR assay can detect 4.8 PFU of titrated Tahyna virus. Assay specificities were determined by testing a battery of arboviruses, including representative strains of Tahyna virus and other arthropod-borne viruses from China. Seven strains of Tahyna virus were confirmed as positive; the other seven species of arboviruses could not be detected by RT-qPCR. Additionally, the assay was used to detect Tahyna viral RNA in pooled mosquito samples. The RT-qPCR assay detected Tahyna virus in a sensitive, specific, and rapid manner; these findings support the use of the assay in viral surveillance.
Animals ; Culicidae ; virology ; Encephalitis Virus, California ; isolation & purification ; Real-Time Polymerase Chain Reaction ; methods ; Reverse Transcriptase Polymerase Chain Reaction ; methods ; Sensitivity and Specificity

Schmallenberg virus (SBV), a novel orthobunyavirus, was first isolated in 2011. SBV preferentially infects the central nervous system of cattle and sheep and causes fever, diarrhea, a drop in milk yields, congenital malformations and stillbirths. Until June 2014, more than 200 scientific publications regarding SBV have been published. Although more than 20 articles on SVB were published in China, most of these articles provided only a brief introduction of the disease without fully discussing the associated disease characteristics. As a new disease, it has been made a focus of the National Research Center for Exotic Animal Diseases at the China Animal Health and Epidemiology Center. In this review, in order to provide a reference for research into SBV in China, we have reviewed the state of current research progress on the etiology, diagnosis and epidemiology of SBV, and vaccine development.
Animals ; Bunyaviridae Infections ; diagnosis ; epidemiology ; veterinary ; virology ; Cattle ; China ; epidemiology ; Goats ; Host Specificity ; Orthobunyavirus ; classification ; genetics ; isolation & purification ; physiology ; Sheep