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

Classification

• Genera
  • Bunyaviruses
  • Phlebovirus
  • Nairovirus
  • Uukuvirus
  • Hantavirus

• Immunologically
  • 35 serogroups
  • 300 types & subtypes

BunyaViruses

• ARthropod BOorne viruses
  • Phlebovirus
  • Nairovirus
  • Uukuvirus
  • Hantavirus

• ROdent BOrne Viruses
  • Bunyaviruses

Bunyavirus Replication

Bunyavirus Replication

Cytoplasm

Genetic Reassortment

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

PPT Slide

Epidemiology

• Determined by distribution of vector and mammalian host

• Humans: accidental dead end hosts

Diagnosis

Presumptive

• febrile illness

• geographic site of exposure

• Sean

• vectors

Confirmation

• virus isolation

• Virus specific IgM

• Rise in antibody titer

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

DONE!!!