FILOVIRUS

MUHAMMAD DARWESH KHOSA

NOMAN HAFEEZ KHOSA

TAXONOMY

Family• Filoviridae

Genus1• Marburg VirusSpecies• Lake Victoria Marburg Virus

Genus2• Ebola VirusSpecies

• Ivory Coast Ebola Virus• Reston Ebola Virus• Sudan Ebola Virus• Zaire Virus

• First Ebola outbreak: 1976 (Zaire, Sudan)– Hundreds

infected– 70%-90% fatal

• Sporadic outbreaks still occur in Africa

• Genome• Linear• Single stranded RNA • Non-segmented• Negative sense

• Capsid• Enveloped• Helical symmetry• Long, filamentous shape(hence “filo”)

• Replication takes place in cytoplasm.

PATHOGENESISAfrica, Philippines 

Cause hemorrhagic fevers with high fatality rates (up to 90%)

Infection appears to be by close contact with infected person

• Highly contagious

First outbreak: 1967 (Marburg, Germany; Yugoslavia)

• Vaccine company was processing primary kidney cells from African green monkeys (Cercopithecus aethiops)

• Several workers developed a hemorrhagic fever

• Several dozen infected by person-to-person transmission

• Fewer than half died

CLINICAL AND BIOCHEMICAL FINDINGS

Extensive liver involvementRenal damageChanges in vascular permeabilityActivation of the clotting cascade

HOST DEFENSE

• Recovery mechanisms from filovirus infections are unknown.

• Fatal infections usually end with high viremia• No evidence of an immune response.• Vaccine

• Experimental

• Developed in 2005

• Protects guinea pigs from infection

Bats are reservoirs?– Suspected Ebola virus hosts

• Epomops franqueti (Franquet's epauleted bat)• Hypsignathus monstrosus (hammer-headed bat)• Myonycteris torquata (little collared fruit bat)

– Suspectecte Marburg virus host• Rousettus aegyptiacus (Egyptian fruit bat)

COMPONENTS

•NP - nucleoprotein•VP35 - nonstructural•VP40 - matrix protein•GP - glycoprotein spike•VP30 - transcription factor•VP24 - virus assembly,

STAT1 inhibitor