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Bunyaviridae. Hugh B. Fackrell fackrel@uwindsor.ca Filename: Bunyavirus.ppt. Bunyaviridae . Structure Classification Multiplication Clinical manifestations Epidemiology Diagnosis Control. Baron’s Web Site. Structure. Spherical enveloped particles 90-100 nm
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Bunyaviridae Hugh B. Fackrell fackrel@uwindsor.ca Filename: Bunyavirus.ppt
Bunyaviridae • Structure • Classification • Multiplication • Clinical manifestations • Epidemiology • Diagnosis • Control Baron’s Web Site
Structure • Spherical enveloped particles • 90-100 nm • virus encoded transcriptase • 2 external glycoproteins • multipartite - 3 segments of SS RNA • antisense - SS RNA C=122
Genera Bunyaviruses Phlebovirus Nairovirus Uukuvirus Hantavirus Immunologically 35 serogroups 300 types & subtypes Classification
BunyaViruses • ARthropod BOorne viruses • Phlebovirus • Nairovirus • Uukuvirus • Hantavirus • ROdent BOrne Viruses • Bunyaviruses
Virus RNA transcriptase - ss RNA + mRNA + ssRNA Bunyavirus Replication Cytoplasm
Serious Bunya Virus Diseases • Crimean Congo Hemorrhagic Fever Virus • Rift Valley Fever Virus • La Crosse Virus • Hanta Virus
Pathogenesis • Early • fever & viremia • Late • encephalitis • retinitis • renal involvement
Epidemiology • Determined by distribution of vector and mammalian host • Humans: accidental dead end hosts
Presumptive febrile illness geographic site of exposure Sean vectors Confirmation virus isolation Virus specific IgM Rise in antibody titer Diagnosis
Control • Control Vectors • arthropods • rodents • Vaccination • Humans: Crimean Congo • Sheep & Cattle : Rift Valley
Crimean Congo Hemorrhagic Fever Virus • Headache • pain in limbs • bleeding from multiple orifices
Rift Valley Fever Virus • Explosive potential • Egypt 1977 • 200,000 cases • 600 deaths
La Crosse Virus • Fever • convulsions • drowsiness • focal neurological signs
Hanta Virus • Rodents - transmission to humans via aerosolized excretions and bites. A wide variety of biting insects. Hanta virus Web site
Hanta Virus • Lipid envelope • susceptible to most disinfectants. • Need to lower pH < 5
Hanta Virus • tripartite negative-sense RNA • L,>>viral transcriptase • M>> envelope glycoproteins • >. nucleocapsid protein
Hantavirus Pulmonary Syndrome • febrile prodrome • followed by • non-cardiogenic pulmonary edema, • hypotension • shock
Hantavirus • Four corners New Mexico • May 1993 8 deaths • April 5, 199468 cases in 17 states • Deermouse in New Mexico - principal reservoir do not cause infections - found in saliva, urine, feces and is shed sporadically -infected animals - blood, organs, saliva feces, urine.
Hanta virus ...continued • Humans visiting holding areas for animals can become infected in five minutes. • outbreaks of this and associated diseases have been observed in Baltimore, Maryland Soeul, Korea Belgium England