Ebola virus

Background

Negative-sense single-stranded RNA virus in the Filoviridae family, related to Marburg virus and Cueva virus
The ebolavirus genus includes five species:
- Zaire ebolavirus (EBOV), the most common
- Bundibugyo ebolavirus (BDBV)
- Reston ebolavirus (RESTV), which does not cause disease in humans
- Sudan ebolavirus (SUDV)
- Taï Forest (or Cote d'Ivoire) ebolavirus (TAFV)

Essentially located exclusively in west Africa
Outbreaks occur where there is food insecurity (with resultant hunting for bush meat), increased population density, and insufficient public health infrastructure
Human-to-human transmission occurs via exposure to contaminated blood or fluids, including providing care to infected family or patient and preparing an infected body for funeral
Mainly infectious during symptoms, which corresponds to viremia

Incubation period 2 to 21 days (generally 3 to 13 days)
Initially starts as a non-specific influenza-like illness with fever, fatigue, myalgias, weakness, and dizziness
Followed by multiorgan involvement and hemorrhagic manifestations (30-50%)
EBOV can persist after resolution of symptoms in privileged sites: the eyes, CNS, male reproductive tract, and mammary glands
Relapse can occur as uveitis or meningitis
Death usually within 6 to 16 days of symptom onset

Ensure to notify the lab before sending samples, and contact Public Health for instructions
- Biosafety level 4 agent
qPCR at the Public Health Laboratory Ontario, but only for Zaire ebolavirus
Canada's National Microbiology Laboratory does RT-PCR, viral isolation, and serology

Supportive care alone can decrease mortality to 20-30%
Monoclonal antibodies
- REGN-EB3 (6% mortality)
- mAb-114 (11% mortality)
- Zmapp (24% mortality)
Medications
- Remdesivir (33% mortality)

Vaccination with a recombinant vesicular stomatitis virus that has its glycoprotein replaced by Ebola virus glycoprotein
- Used in large West African and DRC outbreaks with ring vaccination
- Efficacy 95-100%
- >100,000 doses give