Arena Viruses

Hugh B Fackrell

Filename: Arena.ppt

Arena Viruses

• Structure

• Classification

• Multiplication

• Clinical manifestations

• Epidemiology

• Diagnosis

• Control

Baron’s Web Site

EM of Arenavirus

• Pleomorphic
  • 120 nm

• “Sandy”
  • dense 20 nm particles

Structure of Arenavirus

• Enveloped

• RNA
  • linear or circular
  • 2 strands
  • negative strands

Arena Virus Replication

Reservoir

• Pet hamsters

• Rodent breeding facilities

• Wild Rodents

• Virus spread from rodents by urine and feces.
  • contaminate food or water.

• rodents do not acquire disease

Arena in Humans

• humans are an accidental host.

• aerosol transmission is suspected in human to human.

• human transmission occurs because the virulence of the virus has been increased due to the multiplication in a human host.

• sudden eruption of the disease is due to the lack of exposure.

• disease is acute in humans.

Diseases

• Lymphocytic choriomeningitis

• Argentinean Hemorrhagic fever

• Bolivian Hemorrhagic fever

• Lassa Fever

CDC Arenavirus factsheet

Lymphocytic Choriomeningitis Virus

• found in house mice - world wide.

• incubation 10-14 days.

• most asymptomatic or have mild “cold” symptoms. More severe headache, confusion, photophobia, listlessness, apathy, may have more severe neurological symptoms. In all cases the disease is short lived and not fatal.

Hemorrhagic Fevers

• much more severe and often fatal.

• incubation 10-14 days.

• 2-4 days increasing fever - progressive malaise.

Argentinian Hemorrhagic Fever

• causes mild hepatitis

• farm workers at risk.

• death rate is 15-20%.

Bolivian Hemorrhagic Fever

• causes mild hepatitis

• farmworkers at risk.

• death rate is 15-20%.

Lassa Fever

• discovered in Nigeria, Africa.

• found in wild rodents in Nigeria, Liberia and Sierra Leone.

Lassa Fever Symptoms

• the most serious of the four human arenavirus infections.

• mild cases survive and may go undetected.

• causes severe hepatitis

• Hemoconcentration and elevated SGOT levels usually mean death.

• The death rate among severe cases is 30-60%.

Index case

• reported in a nurse.

• highly infectious. Two attending nurses contracted the disease. One recovered, the second was saved by the passive transfer of the antibodies of the one who recovered.

DONE!!!