bunya virus

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Bunyaviridae

Hugh B. Fackrell

fackrel@uwindsor.ca

Filename: Bunyavirus.ppt

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Bunyaviridae Structure Classification Multiplication Clinical manifestations Epidemiology Diagnosis Control

Baron’s Web Site

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Structure Spherical enveloped particles

– 90-100 nm virus encoded transcriptase 2 external glycoproteins multipartite - 3 segments of

SS RNA– antisense - SS RNA

C=122

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Classification Genera

–Bunyaviruses– Phlebovirus–Nairovirus–Uukuvirus–Hantavirus

Immunologically– 35 serogroups– 300 types &

subtypes

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BunyaViruses ARthropod BOorne viruses

–Phlebovirus–Nairovirus–Uukuvirus–Hantavirus

ROdent BOrne Viruses–Bunyaviruses

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Bunyavirus Replication

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+ mRNA

+ ssRNA

- ss RNA

Virus RNA transcriptase

Cytoplasm

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Genetic Reassortment

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Serious Bunya Virus Diseases

Crimean Congo Hemorrhagic Fever Virus

Rift Valley Fever Virus La Crosse Virus Hanta Virus

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Pathogenesis Early

– fever & viremia Late

– encephalitis– retinitis– renal involvement

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Epidemiology Determined by distribution of

vector and mammalian host Humans: accidental dead end

hosts

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DiagnosisPresumptive febrile illness geographic site of

exposure Sean vectors

Confirmation virus isolation Virus specific IgM Rise in antibody

titer

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Control Control Vectors

– arthropods– rodents

Vaccination– Humans: Crimean Congo– Sheep & Cattle : Rift Valley

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Crimean Congo Hemorrhagic Fever Virus

Headache pain in limbs bleeding from multiple orifices

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Rift Valley Fever Virus Explosive potential Egypt 1977 200,000 cases 600 deaths

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La Crosse Virus Fever convulsions drowsiness focal neurological signs

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Hanta Virus

Rodents - transmission to humans via aerosolized excretions and bites. A wide variety of biting insects.

Hanta virus Web site

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Hanta Virus Lipid envelope

– susceptible to most disinfectants.

– Need to lower pH < 5

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Hanta Virus tripartite negative-

sense RNA – L,>>viral

transcriptase– M>> envelope

glycoproteins– >. nucleocapsid

protein

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Hantavirus Pulmonary Syndrome

febrile prodrome followed by

– non-cardiogenic pulmonary edema,

– hypotension – shock

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Hantavirus Four corners New Mexico

– May 1993 8 deaths April 5, 1994

68 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.

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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, MarylandSoeul, KoreaBelgiumEngland

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DONE!!!