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Infectious Agents 2 Exam 3 > Dr. Wan New > Flashcards

Flashcards in Dr. Wan New Deck (25):

Which of the following reoviruses are important in vet med (CHOOSE ALL OF THEM; still list all of them please)

The first three are the most important for veterinary medicine


Know the vector for blue tongue

Culicoides spp-Biting midges, (no see ums)


Know about orthoreovirus infectivity (what does it get into --> a lot)

•Mammalian- many species
•Avian- chickens, turkeys, geese


Know about avian reovirus infection in chickens and turkeys (what does it cause)

Arthritis,nephrosis, enteritis, chronic resp dz, myocarditis


Know which type of reoviridae are involved in seasonal infections (in other words know when culicoides midges hatch)

Summer and early fall


Genome for reovirus

•All are segmented, linear, double-stranded RNA (except birnaviruses)
•10-12 segments
o ortho & orbi- 10, rota- 11, colti- 12
•Not enveloped
o capsid shell with three layers- outer layer, core layer, inner layer


Rotavirus- seven major groups (A-G, based on VP6) which ones get in swine?

C and E get in swine


Know the Susceptibility of rotavirus to disinfectants and low pH

•Resistant to many common disinfectants and stable at low pH
(vs. orbivirus Bluetongue, which is susceptible)


Know about different serotypes of blue tongue

•There are 25 Worldwide, but only 5 recognized in the United States. Many can be asymptomatic and each serotype has variable virulence.


Know how to control blue tongue disease

•Vx but must match local serotype, Use larvicides and environmental control of Midges


His favorite viruses:

Orthomyxo viruses --> flu


What is majorly responsible for new emergences of flu viruses

•The ability of influenza virus to undergo recombination with other strains while in the pig or human


“Which of the following events at the cleavage site of the HA gene is responsible for the emergence of High Pathogenic Avian Influenza?” aka how do they evolve/ get formed

•Mutation at the cleavage site. Point mutation (drift) recombination insertion( shift)


Relative pathogenicity of the avian influenza viruses in regard to hemagglutinin gene types

•Influenza A viruses are divided into subtypes based on antigenic difference among neuraminidase (N) and hemagglutinin (H)
•Of the 16 H subtypes, only H5 and H7 viruses of certain lineages caused high pathogenic avian influenza → H5N1 is of particular concern because it mutates rapidly and has potential to acquire genes from viruses infecting other species. It also can be shed orally or in feces of birds for 10 days that have survived infection
HA: 1-18 subtypes
•NA: 1-11 subtypes
•18 x 11= 198 HA-NA combinations
•H5 and H7 are pathogenic (THis is in bold)


H3N8 canine influenza and where did it come from

•From the horse tracks in Florida and got into dogs and blew up


In 2015, which of the following subtype A influenza in chickens and turkeys happened in western united states



Know about the genome organization of influenza A viruses (it’s the same as B, C, etc)

SS RNA Neg sense


Which species serves as a mixing vessel for producing pandemic influenza strains (a reason we do not place chicken and pig farms near one another)



What is a reservoir for influenza A viruses

Wild Birds


Arboviral (Arbovirus group A) transmission cycles (there is a picture) --> know about the these
a. EEE

Look at a picture in the study guide
a. North America: Endemic - Bird → Culiseta melanura (mosquito) → Promiscuous feeding mosquitoes → Epidemic - Horses and humans
South America: same as North America but can start with Birds & Rodents

b. Endemic - Bird → Culex tarsalis (mosquito) → Promiscuous feeding mosquitoes or Rabbits (then to Ochlerotatus melanimon) → Epidemic - Horses and humans

c. Endemic - Rodents → Culex spp. Mosquito → Selection through E2 T213R mutation in VEEV ID & IE → VEEV subtypes IAB/IC in mosquitoes → horse → mosquito → humans → mosquitoes


Know the genus species vector of WEE virus

Culex tarsalis mosquito


Know the subtypes of VEE that are the most virulent and epidemic

IAB and IC


Know about the alpha viruses and their vectors (cannot distinguish them from one another clinically)


•EEEV = Culiseta melanura
•WEEV = Culex tarsalis
•VEEV= multiples mosquitoes → culex, psorophora, aedes


Know where the high viremias are

High in passerine birds starlings and wading birds
Low viremia: humans and horses, because they’re dead end hosts


Know clinical features of disease by all these viruses (its all the same)

Encephalitis and febrile disease