Unit 5: Exotic Viral Diseases Flashcards
what are the stages of disease emergence?
- agent only in animals
- primary infection
- limited outbreak
- long outbreak
- exclusive human agent
what are some areas where disease outbreaks can originate from?
- farming (measles)
- pets
- hunting (ebola)
- zoos
- domestic environments always more common
what are some methods of disease transmission?
- touch
- oral/faecal
- respiratory
- blood
- vector
- sexually
what is an emerging virus?
- new species
- new geographical location
- new tropism or characteristics
what are some notable emerging viruses in animals?
- african swine fever
- feline coronavirus in cyprus
why do most viral emergences rarely lead to pandemics?
- R0 value <1
- restriction and ecological factors
- human factors
what are the three stages that lead to an epidemic?
- spillover events
- limited transmission events (outbreaks)
- sustained onward transmission = epidemic
why are emerging viruses riskier now than in previous history?
- increased population with close animal contact
- mass farming and increased animal population
- habitat destruction = more contact
- global interconnectivity = increased exponential spread probability
how is hendra virus spread?
bats -> horses via faeces/urined/chewed pulp
can spread horse -> horse and horse -> human
75% fatality rate (but rare)
what are the 4 most common detection methods for detecting viruses?
- PCR
- ELISA
- CPE (cytopathic effect)
- electron microscopy
what are Koch’s postulates for establishing relationship between a microbe and disease?
- mircoorganism in abundance in all organisms with disease + not in healthy
- isolated from diseased organism + grown in pure culture
- cultured should cause disease when intorduced in healthy organism
- re-isolated from inoculated host + identical to original specific causative agent
how can you identify an unknown virus?
- sequencing - degenerate primers or isolate organism
- next-gen sequencing (illumina, nanopore)
- metagenomic sequencing
which diseases should we aim to control?
- high mortality
- economic effect
- zoonotic
- exotic to UK
what tools are available to track an outbreak?
- animal tag numbers
- animal passports
- vet reports
- diagnostics
- surveys
- prediction models
- sequencing
what is sequencing good for?
- outbreak tracking
- identifying transmission chains
- tracing orgins of an outbreak
- variant detection
