Zoonosis Flashcards
1
Q
one health
A
worldwide initiative that recognizes that human health is connected to animal health and our shared environment
2
Q
when was one health first used?
A
in 2003-2004 associated with SARS (severe acute respiratory disease) emergence and then subsequently by the spread of highly pathogenic avian influenza H5N1
3
Q
who was the 1st president for one health?
A
Dr. Mahr from ISVMA
4
Q
zoonosis
A
diseases passed between animals and humans
at least 61% of human pathogens are zoonotic
5
Q
reverse zoonosis
A
pathogen that humans can pass to animals
6
Q
endemic
A
usual level of disease in a geographic area
7
Q
epizootic
A
disease cases in animals in excess of normal
animal version of an epidemic
8
Q
epidemiology
A
study of disease
9
Q
reservoir host
A
living organism that harbors a pathogen
10
Q
amplification host
A
host that develops high concentration of pathogen
11
Q
sentinel
A
organism that reacts to contaminant/pathogen before impact to people
12
Q
seroprevalence
A
number of seropositive individuals in a population
13
Q
herd immunity
A
increasing proportion of resistant individuals which decreases susceptible population
14
Q
what are sentinels used for?
A
they are good epidemic indicators and bioterrorist event indicators
15
Q
seropositive
A
presence of an organism or antibodies
allows us to predict epidemics
16
Q
sylvatic transmission
A
animals living in their native habitat get sick and it spills over to us
17
Q
domestic transmission
A
animals residing in our homes/work get sick and then we contract it from them
18
Q
peri-domestic transmission
A
overlap of species disease transmission
19
Q
spill-over
A
when disease amplifies in its natural cycle to a level to where it spills over into humans
20
Q
direct contact disease transmission
A
bite, scratch, contact with infected tissues
ex: rabies, Q-fever, ringworm, herpes B
21
Q
indirect contact disease transmission
A
food/water borne or touching infected object (fomite)
ex: Salmonella, E. coli, Giardia
22
Q
aerosolization disease transmission
A
inhalation, contact with respiratory droplets
ex: brucellosis, psittacosis
23
Q
vector-borne disease transmission
A
mosquitoes, ticks, fleas
ex: Rocky Mountain Spotted Fever, West Nile Virus
24
Q
what 4 things do we look for when tracking a possible bioterrorism threat?
A
- clustering of illness of humans or animals
- unusual age distribution
- illness outside usual season
- disease unusual for geographic area
25
case fatality rate (CFR)
proportion of infected animals that die from a disease
26
CDC rating pathogen system
CDC rates agents by how easily they are disseminated, mortality rate, and public panic they cause
27
CDC category A pathogens
easily transmitted person to person, high mortality, potential for public panic and social disruption
28
why would livestock be targeted for bioterrorism?
it would be disastrous for our food supply
29
class A bioterrorism
extremely infective to animals and humans, easy to procure from animal reservoir, can easily be grown in large quantities
aerosolized dispersal can lead to extended infections of potentially fatal pneumonia and food/water contamination
30
prions
causes bovine spongiform encephalitis, chronic wasting disease, scrapie, Creutzfeldt-Jakob disease (vCJD)
31
dermatophytosis
"ringworm"
fungal infection starts as red, itchy, scaly circle
40 types of fungi can cause ringworm: trichophyton, microsporum spp.
tx: antifungals for 2-3 weeks
32
toxoplasmosis
cat eats infected prey
protozoal parasite
T. gondii burrows into walls of the cat's small intestine forming early stage cells called oocysts that the cat eliminates in feces usually for a period of 2-3 weeks
can cause abortions in pregnant women as well as birth defects and AIDS in immunocompromised people
33
how are protozoans transmitted?
accidental ingestion (usually water)
34
Giardia hosts
dog, cat, cattle, pig, primates
35
Cryptosporidia hosts
large animals, wildlife
reptile strain not shown to be zoonotic
shows acid fast positive
36
Balantidium hosts
pigs, primates
37
Sarcocystis hosts
cattle, pigs
38
Chagas
American trypansomiasis
seen in tropics, causes sleeping sickness
flagellate protozoan that transmits through vector or contaminated food
vector: kissing bug; bite then defecate near bite
commonly seen in poverty, vet occupation, hunters
39
Chagas CS
acute phase: flu-like symptoms with chagoma and/or romanas
indeterminant phase: asymptomatic for 5-40 years, parasite disappears from blood
chronic phase: organ failure, fatal if untreated, causes abortions in pregnant women
40
Scabies
sarcoptes scabiei
transmisison: direct contact
self limiting in humans
CS: rash, itching
control by treating animal source
serious outbreak in animals when they are immunocompromised
41
larva migrans
transmission: fecal-oral
toxocara, Ancylostoma, Strongyloides, Baylisascaris
42
Toxocara
common dog roundworm
43
Ancylostoma
dog hookworm that causes cutaneous larval migrans
44
Strongyloides
moves more quickly through the skin
45
Baylisascaris
poor prognosis especially if it enters the brain, eye, lung
humans CS: cough, wheezing, abd pain, strabismus, blindness
46
Hydatidosis
Echinococcus: tapeworm
proglottids are identical to Taenia
hosts: dogs, wolves, herbivores
transmission: fecal-oral
can take up to 20 years for symptoms to occur
cysts mostly found in liver, lungs, or brain
47
Trichinosis
round worm
host: pigs
transmisison: ingestion
common from eating wild game, especially where beef is mixed with a little pork
48
Schistosomiasis
"Bilharzia", snail disease
seen in tropics, not US
host: snail
transmission: contact with fluke
in US we have "swimmer itch" related fluke
49
Leptospirosis
spirochete
transmission: direct (shed in urine), indirect (environmental)
can't live in dry environment, requires high humidity
control by vaccinating, antibiotics, good hygiene, don't drink stream water
50
Leptospirosis animal CS
icterus, bloody diarrhea, renal failure
51
Leptospirosis human CS
mild form: non-specific CS
severe form: multi-organ failure/meningitis
52
Tuberculosis (TB)
humans susceptible to all 3 strains
cell-mediated hypersensitivity
53
Mycobacterium bovis TB strain
rare transmission in US
hosts: cattle, deer
54
M. tuberculosis strain
reverse zoonosis
hosts: humans, birds, elephants, mammals
prolonged contact with actively infected individual
55
M. avian TB strain
causative agent of Johne's disease
host: birds
seen in patients with Crohn's disease
56
Q-fever
Coxiella Burnetti
can live in environment for 6 months
sheep and goats are the most common reservoir
transmission: aerosol
57
Q-fever animal CS
subclinical or spontaneous abortions
58
Q-fever human CS
50% subclinical, 50% flu-like symptoms
hepatitis, encephalitis
chronic form: endocarditis (infection of heart valves) which leads to night sweats, fatigue, shortness of breath, weight loss, limb swelling
59
Q-fever tx
long-term antibiotics
60
Q-fever prevention
hygiene, pasteurization, vaccines
61
cat scratch fever
Bartonella henselae
host: felids
cats become infected through flea bites, fights with infected cats, or blood transfusions
most cats are subclincal
transmission to humans: cat bites/scratches
62
cat scratch fever human CS
lymphadenitis, abscess at lesion, fever, malaise, splenomegaly
63
cat scratch fever tx
supportive care
difficult to eliminate with antibiotics
most human cases are self limiting
64
psittacosis
Chlamydia psittaci
associated with pet birds
called ornithosis when not from a psittacine
transmission: fecal dust, direct contact (bites, beak-to-mouth contact)
65
psittacosis CS
flu-like symptoms that initially mimic typhoid fever, prostrating high fevers, joint pains, diarrhea, conjunctivitis, nose bleeds, low WBC levels
rose spots called Horder's spots may develop and can turn into pneumonia
66
bird fanciers lung
immune mediated
hypersensitivity pneumonitis caused by inhalation of bird dropping extracts and antigens in feathers
high mortality
67
Lyme disease
Borrelia Burgdorferi
midwestern/eastern US: Ixodes scapularis or deer tick are main vectors
primary reservoir host: white footed mouse
ticks in nymph stage cause the most cases due to their small size and painless bite
68
tick life stages
egg ---> larva ---> nymph ---> adult
each stage after hatching they suck blood then drop off and enter dormant period, then molt to enter the next stage
68
how do you remove a tick?
gasp tick as close to skin as possible and pull straight out
save for ID
69
Lyme disease animal CS
lameness, lymphadenitis
70
Lyme disease erythema migrans
appears at the site of the tick bite ~ 7-10 days afterwards
CS: red papule that expands into a large lesion, fever, myalgia, arthralgia, malaise, headache, stiff neck, lymphadenopathy
can cause development of dyspnea, uveitis, and memory loss
71
Lyme disease erythema migrans secondary smaller migrans CS
secondary smaller lesions form 3-5 weeks after bite along with facial nerve palsy, dizziness, syncope, chest pain, palpitations, dyspnea, uveitis, meningitis
72
Lyme disease late stage CS
autoimmunity, arthritis, meningitis, encephalitis
73
Brucellosis
undulant/malta fever or Bang's disease
caused by Brucella spp. (B. abortus in cattle, B. canis in dogs)
transmission: direct contact, ingestion, inhalation
very resistant to environmental changes
74
Brucellosis animal CS
abortions, orchitis (inflammation of testes), lymphadenitis
75
Brucellosis human CS
undulating fever, muscle and joint pain, lymphadenitis, meningitis/carditis
fatal if untreated
76
anthrax
"wool sorters disease", Bacillus anthracus
spore formers that are released from dead/dying host
over 1,200 strains
very resistant
wool sorters have contact with spores in sheep's wool and can get cutaneous form
77
what are the 3 different forms of anthrax?
1. cutaneous: spores found on animal products or in soil
2. ingestion: contaminated meat
3. inhalation: spores on animal products or terrorism
78
anthrax inhalation phases
1st phase: flu-like symptoms
2nd phase: dyspnea, bloody vomit/diarrhea, sepsis, death within 24-36 hours
79
Rocky Mountain Spotted Fever
Rickettsia rickettsi
tick vector: American dog tick in this area (Dermacentor), Brown dog tick in South (Rhipicephalus)
takes a while to transmit: minimum 4 hours
found in small animals and wildlife
80
Rocky Mountain Spotted Fever dog CS
flu-like symptoms
severe form: neurologic signs, bleeding, heart damage
81
Rocky Mountain Spotted Fever human CS
flu-like symptoms followed by rash and neurologic, pulmonary, and circulatory damage
82
Tularemia
rabbit fever
Francisella tularensis is a highly infectious bacterium that causes it
can survive 3-4 months in mud, water, or dead animals and is infective for > 3 years in frozen rabbit meat
US reservoir hosts: cottontail rabbits, ticks, deer flies
transmission: aerosol, insect bite, direct contact, ingestion
83
Tularemia BTT and prevention
BTT: food, water, aerosol
prevention: avoid mowing over dead animals, wear gloves when handling sick animals, insect repellent
84
Tularemia animal CS
swollen lymph nodes, ulcers, diarrhea, weakness, dyspnea
85
Tularemia in humans
ulceroglandular is most common form: skin ulcer appears at site of transmission
glandular form: lacks ulcer
transmission: vector bite, contact with infected animal
all cases start with flu-like symptoms but can progress to pneumonic if untreated
86
Tularemia: oculoglandar and oropharyngeal forms
oculoglandular transmission: eye (ex: butchering an animal and rubbing eye); CS: irritation and inflammation of eye, swelling of lymph glands in front of ear
oropharyngeal transmisison: contaminated food; CS: sore throat, mouth ulcers, tonsillitis, swelling of lymph glands in neck
87
Tularemia: pneumonic and typhoidal forms
pneumonic transmission: aerosol or secondary to untreated forms, most serious form; CS: cough, chest pain, difficulty breathing, lung infiltrates
typhoidal: non-specific combination of other forms; CS: fever, myalgia, malaise
88
plague
Yersinia pestis
natural cycle in wildlife but spill-over occurs when there is epizootic
hosts: rodents, rabbits, cats (cats particularly susceptible)
dogs are incidental hosts and don't usually become ill but can bring home fleas
vector: fleas
89
plague CS
Bubonic plague: buboes (swollen lymph nodes), flu-like symptoms, toxemia
septicemic from flea bite: purpura, epistaxis, hematuria, DIC, tissue necrosis
pneumonic: person to person transmission, least common form
90
plague tx
must begin within 24 hours of symptom onset for survival to be likely
