Emerging and re-emerging viruses
infectious agents that are either newly identified in a population or have experienced a
resurgence after a period of decline, posing a public health threat.
1
,Ebola virus (EBOV) Filoviridae Replication cycle
1. Macropinocytosis
Kenmerken 2. Genome is inside endosome, pH decrease and genome escapes
3. Replication of the genome, -ssRNA → +ssRNA → -ssRNA
- Class V, (-)ssRNA virus 4. Transcription into mRNA and translation into proteins
- Enveloped
- Non-segmented genome
- Helical
- Gives Ebola Virus Disease (EBV)
Symptoms
- First phase → Headache, Fever, Sore throat, Aching muscles
- Second phase → Nosebleeds, internal and external bleeding,
impaired liver function, Rash, Vomiting, Diarrhea, multi organ failure
2
, Zoonotic origin GP A82V
Fruit Bat → Intermediate host (potentially pigs) → Humans + other primates Is a mutation of EBOV adapted to humans. The mutation occurs in the GP
of the virus. It has an increased infectivity in human cells.
A lot of outbreaks in Central Africa 82V enhances infectivity by decreasing the threshold for activation of
membrane fusion activity triggered by the host factors cathepsin B and
NPC1
Transmission
From wild animals:
Fruit bats in forest-savannah to other wild animals → To humans in rural
villages → To humans in urban towns and cities → To medical facilities
Human to human: Improvements since the West Africa Ebola outbreak
- Direct contact - Diagnostics: GeneXpert, RDTs, ‘real time’ sequencing
- Body fluids (blood, vomit, genital and nasal secretion, urine, ..) - Ebola Treatment Unit: CUBE
- Sexual - Biosecure Emergency Care Units for Outbreaks
- Droplets which infect surfaces - Clinical care: MEURI and treatments
- Through air is NOT common with ebola - Vaccination: rVSV-ZEBOV GP
- Viral vector-based vaccine that utilizes a modified vesicular
Geography and outbreaks stomatitis virus (VSV) to deliver the genetic material encoding the
glycoprotein (GP) of the Ebola virus, aiming to stimulate an
- Origin of Ebola is in Central- and West-Africa (Congo) immune response against Ebola.
- Still a lot of outbreaks in West-Africa
3
, Laboratory diagnosis of Ebola virus disease (EVB) Vaccines
Convalescence = herstel - rVSV ZEBOV vaccine (Merck) (Ervebo® (FDA, EMA, 2019))
Is a viral vector-based vaccine against Ebola virus disease (EVD).
It utilizes a replication-competent vesicular stomatitis virus (VSV)
engineered to express the surface glycoprotein (GP) of the Ebola
virus. The vaccine prompts an immune response by presenting the
Ebola GP to the body's immune system, preparing it to recognize
and combat Ebola virus infections.
- Ad26 EBOV GP/MVA BN (J&J) (Zabdeno® (Ad26.ZEBOV))
- + a Booster Mvabea® (MVA-BN-Filo)
→ Double shot, er is dus ook een booster nodig => Niet zo handig
in Africa omdat mensen dan een 2e keer moeten terug komen na
een paar maanden
Xpert Ebola Assay (PCR detection) Ring vaccination
We don't vaccinate everyone, we do ring vaccination => The closest
Easy to perform, quick results and can be done in remote settings.
contacts and contacts of these close contacts
It uses 2 targets, NP and GP.
- GP = Present in vaccinated and infected people
- NP = Not in vaccine, so only people who are infected have the mRNA
encoded for NP in their blood
Machine can see difference between vaccinated people and infected
people because it targets besides GPs also NPs
Rapid Diagnostic tests voor EVD diagnosis
Typically work by detecting viral antigens or antibodies in a patient's blood
or other body fluids. The tests often utilize lateral flow immunoassay
technology, where specific antibodies are immobilized on a strip. When the
sample is applied, any viral antigens or antibodies present will bind to the
immobilized antibodies, producing a visible signal, such as a color change,
indicating a positive result (looks like covid rapid test).
4
infectious agents that are either newly identified in a population or have experienced a
resurgence after a period of decline, posing a public health threat.
1
,Ebola virus (EBOV) Filoviridae Replication cycle
1. Macropinocytosis
Kenmerken 2. Genome is inside endosome, pH decrease and genome escapes
3. Replication of the genome, -ssRNA → +ssRNA → -ssRNA
- Class V, (-)ssRNA virus 4. Transcription into mRNA and translation into proteins
- Enveloped
- Non-segmented genome
- Helical
- Gives Ebola Virus Disease (EBV)
Symptoms
- First phase → Headache, Fever, Sore throat, Aching muscles
- Second phase → Nosebleeds, internal and external bleeding,
impaired liver function, Rash, Vomiting, Diarrhea, multi organ failure
2
, Zoonotic origin GP A82V
Fruit Bat → Intermediate host (potentially pigs) → Humans + other primates Is a mutation of EBOV adapted to humans. The mutation occurs in the GP
of the virus. It has an increased infectivity in human cells.
A lot of outbreaks in Central Africa 82V enhances infectivity by decreasing the threshold for activation of
membrane fusion activity triggered by the host factors cathepsin B and
NPC1
Transmission
From wild animals:
Fruit bats in forest-savannah to other wild animals → To humans in rural
villages → To humans in urban towns and cities → To medical facilities
Human to human: Improvements since the West Africa Ebola outbreak
- Direct contact - Diagnostics: GeneXpert, RDTs, ‘real time’ sequencing
- Body fluids (blood, vomit, genital and nasal secretion, urine, ..) - Ebola Treatment Unit: CUBE
- Sexual - Biosecure Emergency Care Units for Outbreaks
- Droplets which infect surfaces - Clinical care: MEURI and treatments
- Through air is NOT common with ebola - Vaccination: rVSV-ZEBOV GP
- Viral vector-based vaccine that utilizes a modified vesicular
Geography and outbreaks stomatitis virus (VSV) to deliver the genetic material encoding the
glycoprotein (GP) of the Ebola virus, aiming to stimulate an
- Origin of Ebola is in Central- and West-Africa (Congo) immune response against Ebola.
- Still a lot of outbreaks in West-Africa
3
, Laboratory diagnosis of Ebola virus disease (EVB) Vaccines
Convalescence = herstel - rVSV ZEBOV vaccine (Merck) (Ervebo® (FDA, EMA, 2019))
Is a viral vector-based vaccine against Ebola virus disease (EVD).
It utilizes a replication-competent vesicular stomatitis virus (VSV)
engineered to express the surface glycoprotein (GP) of the Ebola
virus. The vaccine prompts an immune response by presenting the
Ebola GP to the body's immune system, preparing it to recognize
and combat Ebola virus infections.
- Ad26 EBOV GP/MVA BN (J&J) (Zabdeno® (Ad26.ZEBOV))
- + a Booster Mvabea® (MVA-BN-Filo)
→ Double shot, er is dus ook een booster nodig => Niet zo handig
in Africa omdat mensen dan een 2e keer moeten terug komen na
een paar maanden
Xpert Ebola Assay (PCR detection) Ring vaccination
We don't vaccinate everyone, we do ring vaccination => The closest
Easy to perform, quick results and can be done in remote settings.
contacts and contacts of these close contacts
It uses 2 targets, NP and GP.
- GP = Present in vaccinated and infected people
- NP = Not in vaccine, so only people who are infected have the mRNA
encoded for NP in their blood
Machine can see difference between vaccinated people and infected
people because it targets besides GPs also NPs
Rapid Diagnostic tests voor EVD diagnosis
Typically work by detecting viral antigens or antibodies in a patient's blood
or other body fluids. The tests often utilize lateral flow immunoassay
technology, where specific antibodies are immobilized on a strip. When the
sample is applied, any viral antigens or antibodies present will bind to the
immobilized antibodies, producing a visible signal, such as a color change,
indicating a positive result (looks like covid rapid test).
4
