microbio 2125 unit 6 part 24 - Ebola Virus Disease (EVD) and Marburg Virus Disease (MVD)

Etiological Agent: of ebola

genus Ebolavirus (ebola virus disease (EVD))filovirus

Etiological Agent: of marbug

genus MarburgVirus ( marbug virus Disease (MVD)) filovirus

Distinguishing characteristics of etiological agent:

• Enveloped, filamentous (thread-like) virus

• Nonsegmented, negative-sense ssRNA virus

• Requires Biosafety Level 4 containment

• Animal reservoirs (likely bats)

Cause viral hemorrhagic fevers

Virulence Factor(s):

• Rapid replication and systemic spread

• Induction of massive cytokine release ("cytokine storm")

• Severe disruption of vascular integrity leading to hemorrhage

• Immunosuppression and direct cytotoxic effects on host tissues

Predisposing Factors:

• Contact with infected bodily fluids

• Handling infected animals (e.g., fruit bats, non-human primates)

• Lack of access to protective equipment or healthcare

Transmission:

• Direct contact with blood, bodily fluids, or tissues of infected individuals

• Contaminated medical equipment

• Nosocomial spread (healthcare settings)

• Not airborne, but highly infectious via fluids

• Animal reservoirs

• can be contracted from bats

Syndrome (signs + symptoms):

• Early: Fever, headache, vomiting, diarrhea

• Later: Hemorrhagic diathesis (severe internal and external bleeding)

• Bleeding from eyes, nose, mouth, and other orifices

• Death often occurs by 10 days post-infection due to multi-organ failure and shock

Affected body region/system:

• Vascular system (extensive hemorrhage and clotting defects)

• Liver (necrosis)

• Immune system (severe suppression)

• Multiple organ systems affected

Treatment:

introduction of coagulating factors, maintenance of O₂ and blood levels

Prevention:

• Ervebo vaccine (effective for Zaire ebolavirus)

• no vaccine for marbug virus yet

• Experimental vaccines in development for other strains

• Strict infection control procedures and use of PPE

• Avoid contact with infected animals or human remains

• Quarantine and isolation of suspected cases

Other notes:

• Mortality rate ranges from 80–90% in many outbreaks

• Outbreaks usually occur in sub-Saharan Africa

• Fast and coordinated response essential to containment

• Marburg virus is similar in structure and pathology but has fewer outbreaks documented