College aantekeningen
Notities Research track advances in pandemic preparedness
Notities van de research track advances in pandemic preparedness
[Meer zien]Voorbeeld 4 van de 36 pagina's
Voorbeeld 4 van de 36 pagina's
In winkelwagen
Voorbeeld van de inhoud
1Definitions
- Shedding
- Host adaptation
- Recombination
- Species barrier
- Reservoir = environment in which a pathogen naturally lives
- Virus evolution
- Cultivation system
- Environmental persistence
- Replication
- Serology
- Aerossol
- Permissive cell has the capacity to replicate virus. <-> abortive
- Susceptible individual = individual with cells that have the receptor. A virus can enter
a susceptible cell, but it cannot replicate. <-> resistant
- Vector
- High fidelity = copy looks like the original
- Infectious virus = virus that can make you sick. Virus is infectious or not. Viral RNA is
not infectious virus.
Transmission
- Forms of transmission:
- Airborne: droplets, aerossol (smaller - travel longer through the air - more
dangerous)
- Formite transmission: bacteria or virus remain on surface and cause infection
- Fecal oral transmission: foodborne (contaminated food), waterborne (drinking
contaminated water, swimming)
- Bloodborne: transfusion, needle stick injuries
- Vertical transmission: transplacental, perinatal
- Mucosal / skin to skin
- Vector: mosquitos, ticks, midges
- From human to human (people in your household, places with a lot of people,
hospital staff, food handlers)
- From animals (domestic animals, wild animals, pets, rodents, mice (via urine or stool
- aerosolization or touch it)
- What boosts transmission?
- Behaviour
- Occupational hazards
- Forest worker - more exposed to animals
- ..
- Overpopulation
- Transport
- Immune deficiency
- Bad healthcare
- Pregnant woman
- Immune status, not vaccinated of yourself or of your community
, - It is often a combination of different routes of transmission
Questions
- An abortive infection is one that progeny virus is not produced
- Which of the following virus types has nucleic acid functions directly as mRNA?
Single stranded positive sense RNA viruses
- The genome of a known RNA virus could be any except ds circular
- Most enveloped animal viruses may enter the host cells by endocytosis
- Virus particle = virion
- A structural component that is found in all viruses is the capsid
- envelope = green
- What is the most common cause of aseptic meningitis of viral etiology? enteroviruses
- Which one of the following infection routes are most often involved in the neonatal
transmission of hepatitis B virus (HBV)? Fetal contact with infected blood during
childbirth
- The finding of large, multinucleated, clumps of cells in the bronchial secretions of a
2-year-old girl with acute bronchopneumonia suggests that this infection is caused by
RSV
- What does the reproductive number of a virus tell us? How many contacts will be
infected from one case, R0
- How are arenaviruses spread? Aerosols of urine from infected small animals
- Which is a major characteristic of the bunyavirus family? Amplify by persistent
infection of midges, mosquitoes, sand flies, ticks
,2
Difference between endemic, pandemic and epidemic
- Disease that is present = endemic
- A lot of cases, big increase as compared to before = epidemic
- Epidemic spreads globally = pandemic
Zoonoses
- Spillovers are a growing threat
- = infectious diseases that can spread from animal to human
- They are clinically important.
- Important to control diseases in animals. Consider health as a whole. Better control
of disease in animals - we will be less vulnerable. Focus on prevention.
Type of hosts
- Natural host:
- Some of the viruses have a natural host
- Virus can circulate but no disease
- Example, bats, waterbirds
- Secondary transmission host
- Animal that is close to us
- Disease
- End / spillover host
Major diseases of animal origin affecting human health
When we see a virus emerge in a region we should assess what is the risk for the rest of the
world.
Spillover and cross species transmission
Spillover from natural host - reach domestic animals - further potential for amplification in
domestic animal - increased risk for spillover to humans
Spillover to humans via natural host or via domestic animals
Transmission via a vector or from human to human
Good surveillance, fast respons - we see the little spillover event, we are aware - limit the
spread in domestic animals - limit the spillover to humans
5 stages through which pathogens of animals evolve to cause disease confined to
humans
Stage 1: agent only in animals
Stage 2: only from animals
Stage 3: from animals to humans + little human to human transmission
Stage 4: spillover from animals to humans + sustainable circulation in humans
Stage 5: evolved to human to human transmission
Determinants of cross species transmission or spillover
When is it more likely to happen based on what already happened?
- RNA viruses rather than DNA viruses
- Varies among host species owing to differences
, - Viral richness is high for bunya, flavi and arenaviruses in rodents, high
number of these viruses in rodents. They can eventually spillover to humans
- Opportunity for contact with humans
- …
- We have to worry certain animal reservoir more in certain locations
Viral traits = traits that predict zoonotic potential of a virus
Which viruses can affect the widest variety of species? These might affect humans as well
Routes of transmission
- By direct contact with animals
- ..
Depends on the virus
The error prone replication of RNA viruses
How viruses challenge their genome, how can some do more than others?
- RNA dependent RNA polymerases are error prone
- Most RNA viruses cannot use the proofreading machine or encode for a protein with
this function
These 2 features results in the fact that RNA viruses have a higher mutation rate
Coronaviruses have the proofreading capacity.
Mutations can be deleterious, neutral or beneficial
- Bad - harm the virus, difficult to infect new cells - extinguish themself
- Neutral
- Good
Balance is important. The more mutations - the more there is a cost of fitness. Mutant
viruses pay the price in terms of fitness.
Viral RNA polymerases
- Template channel, incoming nucleotide channel and out channel
- Conserved motifs indicated with letters
- Catalytic site is the most conserved throughout all viruses - is a very good
target for inhibitors
Genetic recombination
- 2 possibilities
- Self recombination
- Recombination with host
- Much less common
- In bigger viruses
- How does this happen? Via template switch or via virus RNA breakage
- Many factors affect genetic recombination
- Different consequences
Reassortment and genetic shift
- When 2 segmented viruses infect the same cell
- Genetic reassortment causes major changes resulting in a genetic shift.
Voordelen van het kopen van samenvattingen bij Stuvia op een rij:
√ Verzekerd van kwaliteit door reviews
Stuvia-klanten hebben meer dan 700.000 samenvattingen beoordeeld. Zo weet je zeker dat je de beste documenten koopt!
Snel en makkelijk kopen
Je betaalt supersnel en eenmalig met iDeal, Bancontact of creditcard voor de samenvatting. Zonder lidmaatschap.
Focus op de essentie
Samenvattingen worden geschreven voor en door anderen. Daarom zijn de samenvattingen altijd betrouwbaar en actueel. Zo kom je snel tot de kern!
Veelgestelde vragen
Wat krijg ik als ik dit document koop?
Je krijgt een PDF, die direct beschikbaar is na je aankoop. Het gekochte document is altijd, overal en oneindig toegankelijk via je profiel.
Tevredenheidsgarantie: hoe werkt dat?
Onze tevredenheidsgarantie zorgt ervoor dat je altijd een studiedocument vindt dat goed bij je past. Je vult een formulier in en onze klantenservice regelt de rest.
Van wie koop ik deze samenvatting?
Stuvia is een marktplaats, je koop dit document dus niet van ons, maar van verkoper LindeVanAelst. Stuvia faciliteert de betaling aan de verkoper.
Zit ik meteen vast aan een abonnement?
Nee, je koopt alleen deze samenvatting voor €4,49. Je zit daarna nergens aan vast.
Is Stuvia te vertrouwen?
4,6 sterren op Google & Trustpilot (+1000 reviews)
Afgelopen 30 dagen zijn er 53022 samenvattingen verkocht
Opgericht in 2010, al 14 jaar dé plek om samenvattingen te kopen