Pelzer Flashcards
What is the most common arboviral disease in the US?
West Nile Virus
What type of virus is WNV?
Flavivirus
How is WNV transmitted?
mosquitos, blood transfusions, organ donations; what sucks is that blood is screened, but organs are not
What animal is the reservoir for WNV?
Passerine birds aka perching birds
What 3 species are primarily effected by WNV?
humans, horses, crows and jays
When do we see most cases of WNV (traditionally)?
late summer, early fall; but climate change…
Are humans typically asymptomatic or symptomatic with WNV?
Asymptomatic- 80%
If humans present symptomatically with WNV, what is the typical presentation?
flu like symptoms: sore throat, muscle aches, headaches, lymphadenopathy
What is the percentage of humans infected w/ WNV that are symptomatic? If they are symptomatic, what is the chance of getting the neuroinvasive form?
20%; 1:150
What population (humans) is more at risk for WNV?
> 50 yrs
How do horses present when infected w/ WNV?
fever, encephalomyelitis, muscle twitching, ataxia
How is St. Louis Encephalitis transmitted?
the damn mosquitos again
What is the reservoir for St. Louis Encephalitis?
birds
Why do we see a cluster of infections (in humans) of St Louis Encephalitis in low socioeconomic and older neighborhoods?
decreased trash collection, decreased in maintenance/ repair –> increase in breeding grounds for the mosquitos; less access to adequate medical care
Where do the annual cases of EEE occur in VA?
Tidewater area
Why does the Tidewater area see cases of EEE in VA?
fresh water swamps are breeding ground for mosquitos
Can humans get EEE?
Yes, but they are accidental hosts.
What are the clinical signs assc w/ EEE in a human?
fever, headache, vx, lethargy, aseptic meningitis, or encephalitis delirium, and coma
What population is at risk for severe disease assc w/ EEE?
Children under 15yrs and adults 50yrs>
What is the case fatality rate of those infected w/ EEE?
30%
What is the reservoir for EEE?
passerine birds AND water fowl
What population is at risk for clinical signs (in humans) in regards to WEE?
young adults and <1 yr
In what infection will a child transition from fever, headache, stiff neck, spastic paralysis, and mental confusion -> personality changes, mental retardation, and continued spastic paralysis?
WEE
What is the equine encephalitis that does not have birds as its reservoir?
VEE
VEE: what is the reservoir for endemic strains? epidemic strains?
endemic: rodents and mosquitos; epidemic: horses and mosquitos
VEE: Is direct human transmission possible?
Yes! virus was present in pharynx of 40% of human cases
Where do we see cases of Equine Hendra virus?
Australia
What is the viral agent of equine hendra virus?
henipavirus
What is the reservoir of equine hendra virus?
the damn fruit bats
Equine Hendra virus:How do we think horses are exposed?
Bats are feeding on the fruit in trees; horses are underneath or in passing when bats urinate and thus pick up the organisms
Equine hendra virus: how do humans get the virus?
it MUST go through the horse in order to get to the human
What virus in horses leads to acute respiratory syndrome followed by death in 1-3 days?
Equine hendra virus
What symptoms present in a human with equine hendra virus?
flu-like symptoms that worsen/ progress; 60% fatality rate
How many cases do we see nationally from horses w/ rabies?
40 annually
what are the strains of rabies virus?
fox, skunk, raccoon, bat
What animals are considered at risk when raccoon rabies are established?
non-carnivores like opossums, groundhogs, and beavers because they share the same eco-niche
what are the clinical signs of rabies in horses?
“paralytic” and “dumb”; rubbing of bite site
what sucks about vaccinating a horse for rabies?
it gives the owner a false sense of security
Why is vesicular stomatitis reportable?
It resembles foot and mouth
where does vesicular stomatitis occur?
4 corners
T or F: vesicular stomatitis is only found in the Americas
True
what is the route of transmission for vesicular stomatitis?
midges (and sand flies) and black flies (SubQ or mucosal)
What is the viral agent of vesicular stomatitis?
rhabdovirus, vesciulovirus; serotypes of Indiana and NJ
Where do we typically find infected individuals with vesicular stomatitis?
laboratory setting
What biosecurity status is given to a horse w/ salmonellosis?
orange dot/ isolation
Salmonellosis: what is the most common serotype found in horses?
S. typhimurium
What is the multi- drug resistant phage type of Salmonella?
S. typhimurium DT104
Does S. typhimurium DT 104 or S. typhimurium have an increased potential for zoonotic transmission?
S. typhimurium DT 104
where have several nosocomial outbreaks been reported in regards to Salmonellosis?
veterinary teaching hospitals: horses having surgery for colics
what population is at risk for salmonellosis with low numbers?
immunocompromised, those with concurrent disease, antibiotic use
What is the range of clinical signs present in a horse with salmonelosis?
diarrhea, abortion, septicemia, death (esp in foals)
Where is Rhodococcus equi found?
readily found in soil, esp where domestic livestock graze
When is R. equi found in humans?
if they are severely immunocompromised or have HIV, Downs syndrome
Clinically, what would you expect to find in a foal with R. equi?
pneumonia
Clinically, what would you expect to find in a horse with R. equi?
multifocal ulcerative enterocolitis and pyogranulomatous typhlocolitis -> abscesses
What is the agent - Anthrax?
Bacillus anthracis
Anthrax: are cattle or horses more susceptible?
Cattle
Anthrax: transmission?
inhalation, consumption or inoculation of spores
What are the clinical signs seen in a horse with anthrax?
septicemic form w/ high fever, colic, enteritis w/ hemorrhages, depression and death w/in 2-4 days
Anthrax: what is the most common cutaneous form in humans?
ulcer w/ black eschar
When do horses get infected w/ brucellosis?
accidental; if they share pasture w/ infected cattle or swine; think Yellowstone w/ the buffalos
Brucellosis: clinical signs in horses
fistulous withers, poll evil, fistulous bursitis; may not show signs for as long as 2 years post- exposure
What is the common causative agent of dermatomycosis?
Trichophyton equinum
How do humans get dermatomycosis?
by direct contact w/ horses or indirect contact w/ their blankets, equipment, etc
What are the clinical signs of a horse w/ dermatomycosis?
round, hairless lesions; thickened skin and covered with scales
What is rain rot?
an infection caused by dermatophilus congolensis
What organism develops characteristic septate filaments w/ parallel rows of coccoid cells that form motile flagellated zoospores?
dermatophilus congolensis
What do the lesions look like on horses with dermatophilosis?
clumped hair, paint brush lesions
what do the lesions look like on humans with dermatophilosis?
pustular desquamative dermatitis
A cat presents with enlarged, draining ulcers on distal portions of all extremities, the head, and base of tail. What is our top differential?
Sporotrichosis- sporothrix schenkii
A man treats his cat for sporotrichosis but now has a very painful, ulcerated nodule on his finger… is it possible he got sporotrichosis from his cat? how?
yes! no penetration or interruption needed; cats shed organisms from their wounds and in feces
where is sporothrix schenkii found?
naturally in the soil
what does a horse look like w/ sporotrichosis?
ulcerated nodules; can progress to lymphatic- cording disease where the lymphatic chains become enlarged and rupture; distal limbs
Is MRSA a methicillin resistant staph or strep?
staph
what gene mediates resistance of staph to penicillin?
mecA
what protein does mecA code for on the staph?
PBP2a
what is prevented from binding to the wall of a staph when PBP2a is present?
B- lactams
what are the types of MRSA (2)?
community associated- people at risk who live in crowded areas, frequent contact w/ others, compromised skin, poor hygiene; nosocomial- immunocompromised individuals in a hospital
T or F: horses are colonized by MRSA
True
T or F: 25-40% of the human population is colonized by S. aureus in their nasal passage?
True
How do you clean an area after treating an animal with MRSA?
with a household disinfectant or bleach solution
Where did the outbreak and in what population did M bovis occur?
Michigan, white tail deer
What spp of Mycobacterium is prevalent in AIDS patients?
M. avium/ intracellulare (MAC)
What spp of Mycobacterium has been found in p’s with Crohn’s?
M. paratuberculosis
In what product has M. paratuberculosis been found?
pasteurized milk; clumps of bacterial cells get stuck together, outside is pasteurized, but the core does not
What multi-resistant strain of Mycobacterium has been found in prison populations?
M. tuberculosis
What are the general clinical signs assc with M. tuberculosis in humans?
tuberculous chancre, pulmonary lesions (w/ chronic wasting), disseminated TB (i..e genitourinary infection)
outbreaks of brucellosis in humans is often associated with what dairy product?
non-pasteurized, soft mexican cheese
how would a human get brucellosis?
direct contact (aka fetal fluids) or ingestion or accidental injection w/ RB 51 vaccine
what is the common clinical sign in humans w/ brucellosis?
undulating fever
What disease can you cross react w/ yersinia enterocolitica to get a diagnose?
Brucella spp
Why are brucella spp hard to treat?
intracellular organisms
what is the agent for psuedotuberculosis?
Yersinia pseudotuberculosis
What is the most common symptom of humans presenting with psuedotuberculosis?
appendicitis
What spp of Yersinia produces an enterotoxin similar to that of heat stable E. coli?
Yersinia enterocolitica
What is the reservoir for Yersinia enterocolitica?
Pigs; tonsils
List the respective percentages of those with salmonella: dogs, birds, pet turtles, iguanas?
dogs: 10%; birds: 50%; pet turtles/iguanas: 85%
what is the route of transmission for salmonella typhimurium?
fecal- oral and inhaling vacuum dust
T or F: Salmonella is self-limiting, usually
True
Campylobacter jejuni: what pets do we see w/ it?
puppies and kittens from the pound
Campylobacter fetus fetus: what is the source of the organism to pregnant women?
pregnant and aborting sheep= birthing fluids
T or F: Leptospira interrogans produces outside its host
False, it does not reproduce outside of the hsot
You see a city dog, lapping up a puddle on a busy street on a hot , humid day. You then see a rat pass by… what do you yell at the dog in a panic:
a) STOP YOU WILL GET COCCIDIA!
b) OKAY ENOUGH. I HAVE WATER AT HOME.
c) YOURE GOING TO GET LEPTO! STOP THAT SHIT
C
Can a human get lepto?
yes:
anicteric form- flu like
icteric form- aseptic meningitis w/ jaundice
An owner brings in their pet parrot for some mild GI signs and what looks like conjunctivitis. You notice the owner also has a bad cough. You ask how the owner feels and he tells you he has had a bad cough and chest pain for a few days and is headed to the doctor tomorrow. What do we think is going on? is it zoonotic? if so, how was it acquired?
Psittacosis -> Chlamydophilia psittaci; zoonotic; aerosolized bird droppings
What species of Chlamydophilia is not considered a human pathogen?
C. felis
T or F: seafood products can have erysipelothrix rhusiopathiae
True, along with swine and poultry
A fisherman presents w/ these red, swollen lesions, but upon closer look you see they are circled with a violet color. We become worried about septicemia and endocarditis. What pathogen are we thinking about?
erysipelothrix rhusiopathiae (Erysipeloid)
In swine, what is the causative agent of diamond skin disease?
erysipelothrix rhusiopathiae
