lecture 17- emerging diseases Flashcards
what disease has been re-emerging in reindeer?
orf-like virus , but actually it’s a bovine parapox virus
an emerging disease can be…. (4)
- A ‘real’ emergence of a brand-new disease
- A geographic emergence in an area not previously affected
- Disease can emerge in species formerly not considered affected
- An unexpected increase of disease incidence in a known area and a known species
true or false: an emerging disease must be entirely new
FALSE
what are the risk factors for pathogen emergence
- Rising human population density
- Increased travel
- Trade
- Poor biosecurity
- Inadequate animal health management
- Growing antimicrobial use
- Poverty
- Changing dietary habits
- Climate change
how does travel impact pathogen emergence? why is this a problem?
increased travel increases disease spread
little restrictions for shipping animals (trading, shows, semen, livestock, etc)
how does changing architecture impact virus spread? use PRRSV as example
PRRSV must be enabled (weak virus)
can be enabled by shipping pigs, sharing semen (AI), confining pigs, larger herds
the number of pigs hasnt changed that significantly, but the average herd size has (producers decreasing) - more intensified farms.
true or false: bovine leukemia virus is a slow emerging disease on US dairy farms
true (gradually increasing prevalence)
how has climate change impacted west nile virus spread?
WNV is transmitted by mosquitos and birds
climate change has caused mosquitos and birds to increase their biological range / move north ALSO increased amplification of virus because it replicates more in warm climate –> increased risk of WNV
horses and humans are a ____ host of WNV… what does this mean
dead end host
can replicate, but can’t pass on
what is the clinical sign of MNV
encephalitis
what are barriers of virus spread, generally (3)
geography, compatibility, environment
how did WNV come to north america? what was the response? what is successful?
mosquito from isreal came to new york (single strain)
tried to eradicate mosquitos in new york (stripped trees, etc)
NO- now we have so many strains and is widespread in NA
what is BTV? how is it transmitted?
blue tongue virus
biting midges (cullicoides)
what is Schmallenberg virus?
enveloped, negative-sense, segmented, single-stranded RNA virus
related to Simbu serogroup viruses (naughty viruses)
what are clinical signs of Schmallenberg virus
in calves: malformed, hydranencephaly and cerebelalr hypoplasia
how is Schmallenberg virus transmitted? how, then, does climate change impact transmission?
midges (cullicoides)
wider biological range
what is hendra virus
Hendra virus is a zoonotic virus found solely in Australia. First isolated in 1994, the virus has since been connected to numerous outbreaks of disease in domestic horses and seven human cases. Hendra virus belongs to the genus Henipavirus, which also contains the zoonotic Nipah virus.
true or false: hendra virus is not of human concern?
false- it is zoonotic
how is hendravirus transmitted?
fecal drops from fruit bats (dropped on grass, then grazed by horses)
what risk factors influence PEDV
Poor biosecurity, Inadequate animal health
management, travel, trade, changing dietary habits
what kind of virus is PEDV
corona
what is the predicted way that PEDV caused disease outbreak in the USA from china?
spray dried porcine plasma shipped to USA to feed pigs (protein source)
true or false: it is not likely that PEDV was present in eastern canada prior to the confirmed index farm case
false
where can you find info on emerging infections
CAHSS (canadian animal health surveillance system)
CEZD weekly intelligence reports
WAHIM (world animal health info system)
GLEWS
ProMED
Healthmap.org
