Zoonotic Diseases: Test 1 Flashcards
How are humans infected with
Toxoplasma gondii?
Oocysts in soil and kitty litter
or by
Bradyzoites encysted in PORK
Which zoonotic disease causing agent is a protozoan and can be found within the intestinal cells of cats?
Toxoplasma
Epidemiologists believe this zoonotic disease
comes from cumulative exposure to undercooked meants and not just soil exposure
Toxoplasma
T/F
Toxoplasma infections are usually asymptomatic in immune competent children and adults
TRUE
If a pregnant woman is avoiding eating pork, gardening, and cleaning her cat’s litterbox,
she is worried about
Toxoplasma gondii
A parasitic nematode that is migratory during its larval stages causes diseases known as
Larval migrans
What is the most common cause of
human toxocariasis
and in most cases is asymptomatic?
Visceral larval migrans
Children are at risk for toxocariasis because
of these two common eating conditions
Pica
Geophagia
How is toxocariasis prevented?
Regular antihelminthic tx of dogs, cats, and pups
This is known as the
“Raccoon Roundworm”
Baylisascaris procyonis
The most common form of larval migrans that occurs with infection of the raccoon roundworm, or
Baylisascaris procyonis
are
Ocular and Neurologic
Dogs can function as _____ or _____ hosts
in the life cycle of the raccoon roundworm
Alternate definitive hosts
or intermediate hosts
What is the definitive host of
- Taenia saginata*
- Taenia solium*
The Beef and Pork tapeworms?
HUMANS are the DH
What is the name of the fish tapeworm in which
humans are the definitive host?
Diphyllobothrium
How are cestode zoonoses spread to
a human definitive host?
Humans, as a definitive host, contract cestode zoonoses by
eating meat from intermediate hosts
Humans function as what type of host in the following
cestode zoonoses?
- Echinococcus granulosis*
- Echinococcus multilocularis*
- Taenia solium (Cysticercosis)*
Humans are the intermediate hosts
How are humans infected with cestode zoonoses
if they play the role of intermediate host in the cestode life cycle?
Humans, as intermediate hosts, contract cestode
zoonoses by eating larvated cestode EGGS
Human symptoms of cestode zoonoses caused
by ingesting cestode larvated eggs
are caused by the _____
cyst
Individual, large, fluid-filled cysts in multiple tissues
Hydatid cysts
What causes hydatid cyst disease
and where are the cysts often found?
Echinococcus granulosus
Cysts often found in LIVER and sometimes brain
Echinococcus granulosus, or “Cystic Echinococcus”
is a disease largely associated with what industry?
Sheep industry
What are the intermediate hosts in the life cycle of the pathogen that causes
Hydatid cyst disease?
Sheep and moose
What is the definitive host in a disease caused by
Echinococcus granulosus?
Dogs and Wolves
How is the sylvatic cycle of Hydatid Cyst Disease
maintained?
Through Wolves and Moose
Treating a dog every 6 weeks with _______
is a way to control Cystic (Hydatid) Echinococcus
Praziquantel
A disease characterized by multilocular, small, solid cysts in the liver which then metastasize to the lungs?
Alveolar cyst disease
What causes Alveolar Cyst Disease?
Echinococcus multilocularis
This disease, rare in North America, with an up to 75% fatality rate, has been emerging (re-emerging) in Europe in recent years
Echinococcus multilocularis
How can domestic dogs and cats get
Alveolar Cyst Disease?
Ingestion of hunted rodents
Foxes and Rodents maintain the natural cycle of
Echinococcus multilocularis
T/F:
A human can contract Toxoplasma and Toxocara canis via ingestion of infected meat
TRUE!
What is the major determining factor of if a bacterial agent can be used as a bioweapon?
Its ability to be aerosolized
Francisella tularensis is also called
Rabbit Fever
What is the primary, long-term reservoir of
Rabbit Fever?
RABBITS are the RESERVOIR!
(Rodents and Lagomorphs)
Which animal is most likely to contract
Francisella tularensis?
Domestic CATS
also sheep
How does a cat contract tularemia?
By eating infected rodents or lagomorphs
How does a sheep contract tularemia?
Tick-borne
How does a human contract tularemia?
Usually ticks
but also
DIRECT CONTACT with animals or carcasses
and sometimes Aerosol exposure
Xenopsylla cheopsis is
a vector for this disease
PLAGUE!
Yersinia pestis
What is the primary cycle of Yersinia pestis?
Rodent-Flea-Rodent
How does a cat contract the plague?
By hunting and eating infected rodents
How would a human contract the plague caused by Yersinia pestis?
Flea Bite
Aerosol
DIRECT from animal blood or abscesses
Necrotic eschar at skin entry
is indicative of
The PLAGUE
Which two reportable diseases would be on your differential list
if you have an outdoor cat with
fever, lethargy, sepsis, and anorexia?
Plague and Tularemia
Lymphadenopathy in the cervical region of an
outdoor cat in addition to febrile symptoms and sepsis
could be caused by which agents?
- Yersinia pestis*
- Francisella tularensis*
MAJOR CAUTION is necessary when taking aspirates of this organ of a cat infected with Yersinia pestis
and Francisella tularensis
Lymph node aspirates
are high infectious
Wool Sorter’s Disease is caused by
Bacillus anthracis
This spore-forming bacterium is a threat to veterinarians via 2 modes of transmission.
What are they?
Aerosol
Percutaneous via BLOOD from infected animals
Most vet cases of Anthrax are seen in what species?
Cattle!
What is the initial reservoir of Bacillus anthracis?
Soil!
What do Bacillus anthracis and Yersinia pestis
have in common in regards to clinical signs?
Both form necrotic eschars at the site of entry
What happens after anthrax spores enter the host?
Spore germinate and cause sepsis
DIC (disseminated intravascular coagulation)
comes right before massive edema, shock, and death caused by
_________ from Bacillus anthracis spores
exotoxins
How can you tell if a cow found dead in a field was an anthrax fatality?
Blood not clotted
Rapid bloating
Lack of rigor
Bleeding from orifices
Spores in blood
What is the asymptomatic reservoir host
of Hantavirus?
Rodents
Transmission is primarily aerosol in this worldwide disease caused by inhalation of urine, feces, and potentially saliva of rodents
Hantavirus
What is the secondary mode of transmission for Hantavirus?
Bite from a rodent!
The “New World Disease” in humans
is also known as
HPS
Hantavirus Pulmonary Syndrome
Which Hantavirus syndrome of humans is more fatal?
HPS
Fatal in 40% of human cases
Fever, chills, muscle pain, and headache followed by
increased vascular permeability
HPS
Hantavirus Pulmonary Syndrome
HFRS, the “old world” disease, characterized by
petechial hemorrhaging, renal damage and
cardiovascular shock, stands for ______ and is caused by ______
Hemorrhagic Fever with Renal Syndrome
caused by
HANTAVIRUS
What are the reservoirs for pulmonary fungal infection
disease causing agents?
Birds and bats
Humans, dogs, and cats that are infected with
this pathogen
are not infective because their body temperature is too high for sporulation
Fungal pulmonary infectious agents
- Blastomyces*
- Coccidioides*
- Cryptococcus*
- Histoplasma*
What is the reservoir of Coccidioides immitis?
SOIL!
Coccidioides immitis infects and _____ in
humans, dogs, cats, cattle, and horses
amplifies
The reservoir of this fungal pathogen is
the soil and buildings with
bird feces or bat guano
Histoplasmosis
This fungal pathogen can infect humans, cats, and dogs, and is 90% asymptomatic. Bird feces and bat guano are implicated as the reservoir
Histoplasmosis
Both Histoplasmosis and Blastomyces dermatitides
are soil fungi associated with bird feces and bat guano and can both infect humans, cats, and dogs.
Which one can also infect horses?
Blastomyces dermatitides
Family Orthomyxoviridae causes this
zoonotic virus
Influenza
Which animals can transmit influenza to humans?
Birds and Swine ONLY
What is the reservoir for Avian Influenza?
Wild birds
This animal is susceptible to both human and avian strains of influenza and is often called a
viral mixing vessel
Swine
How do people get influenza?
Direct and indirect contact (contaminated surfaces)
How do swine give influenza to each other?
Aerosolization, Direct contact
How do wild birds get influenza A?
Fecal-oral
Saliva
Nasal secretions
Upper respiratory and reproductive organs are affected in this strain of influenza
LPAI
Low Pathogenicity Avian Influenza
Q fever (Abattoir fever) is caused by
Coxiella burnetti
People that work with pregnant sheep are at risk of contracting
Q Fever (Coxiella burnetti)
How is Coxiella burnetti transmitted?
In birth products, milk
feces, urine
Aerosol
Tickborne
A sheep farmer noticed that his sheep were
not eating, and some were aborting their lambs.
about 3 weeks later, he got a fever, chills and sweats, and a persistent headache. What is the pathogen responsible?
Coxiella burnetti
How do birds get Chlamydiosis?
Fecal-oral route
What types of birds is Chlamydiosis most common in?
Psittacine birds:
Parrots and Cockatiels
How does a human get Psittacosis or Chlamydiosis?
DIRECT HANDLING of an infected bird!
A lady comes in to a doctor’s office and says that she’s been feeling sick. She has a headache, cough, and muscle pain with shortness of breath. She also said she was very sensitive to light.
As the lady checked the time on her phone, the doctor noticed a picture of her pet parrot on the background
and then knew exactly what she had.
What is causing her illness?
Chlamydophilia psittaci
This was first noted in China in 2003 and was originally a bat coronavirus. It jumped to civets and then eventually humans during wild animal markets
SARS
Severe Acute Respiratory Syndrome
John Snow said _____ was transmitted via
fecal-oral route in the water supply.
He also made a bullseye map when he went door to door mapping the cases of this disease
CHOLERA
Robert Koch isolated this bacteria and is responsible for the beginning of Germ Theory
Anthrax
Pasteur is responsible for developing this, which he first tested in ruminants
Vaccines
What causes Typhoid fever?
Salmonella typhi
Typhoid Mary was this type of carrier
Asymptomatic carrier!
Ronald Ross discovered that _____ was transmitted by mosquitoes
Malaria
Walter Reed discovered that _____ was transmitted by mosquitoes
Yellow Fever
What is the reservoir host of West Nile Virus?
Birds
What are the incidental hosts for West Nile Virus?
Humans and horses
When a microbe is replicating but not yet enough for the host to become infectious
Latent Period
When a microbe is replicating but not yet
symptomatic
Incubation period
Rabies, West Nile, EEV and Influenza H5N1
are all in Stage ___ of pathogen emergence
Stage 2
What are the reservoirs of West Nile and EEEV?
Birds
Humans, horses, and dogs are dead end hosts in
these Stage 2 (of pathogen emergence) diseases
West Nile
EEEV/WEEV
What are the reservoirs for Rabies?
Carnivores and Bats
What is the dead-end host of Influenza H5N1 (Bird Flu)
Humans
Name two Stage 3 diseases of pathogen emergence
- Mycobacterium bovis*
- Nipah Virus*
What is the reservoir for Mycobacterium bovis?
Cattle, Bison, and Elk
How do humans contract Mycobacterium bovis?
Via the respiratory route
(poor human to human transmission)
Fruit bats are the reservoir for this disease in Stage 3 of pathogen emergence
Nipah Virus
What is the major manifestation of Nipah Virus infection in humans?
Encephalitis
What is the reservoir for SARS?
Fruit bats!
SARS and H1N1 “Swine Flu” are both in
Stage __ of Pathogen Emergence
4
HIV/AIDS, a Stage 5 disease of Pathogen Emergence,
originated from
Non-human primates
Measles, a Stage 5 disease of Pathogen Emergence,
originated in
Cattle
Smallpox, a Stage 5 disease of Pathogen Emergence,
originated in
Camels
Dengue Fever, a Stage 5 disease of Pathogen Emergence, originated in
Old World Primates
Yellow fever, a Stage 5 disease of Pathogen Emergence, originated in
African primates
Zoonotic diseases comprise ___% of all diseases that infect humans
61%
Zoonotic diseases comprise ___% of all emerging diseases
75%
What ratio of supervisors to workers is the IDEAL
as recommended by NIMS (National Incident Management System: Directive 5)?
1 supervisor : 5 workers
What is the persistently infected wildlife reservoir
of FMD (foot and mouth disease)?
Cape Buffalo
What species is considered the “disease indicator” for FMD?
Cattle
What species serves as the
Amplifying Host
for FMD?
Pigs!
Sheep and goats are lucky because they rarely
suffer signs from FMD. They are known as
_______ hosts for FMD
Maintenance Hosts
T/F:
FMD can cause serious disease in horses and donkeys
FALSE!
Equids are NOT affected by FMD
Severe signs in animals housed on concrete including neurological signs
are indicative of this vesicle causing disease
Swine Vesicular Disease
Horses are only affected by one vesicular disease.
Which one is it?
Vesicular stomatitis
FMD can cause abortions in this species
Cattle
FMD can reside in the pharyngeal tissue of cattle for
___ to ___ months
6 - 24 months
FMD can reside in the pharyngeal tissue of
sheep and goats for
__ to __ months
4 - 6 months
This paramyxovirus that affects ruminants has been eradicated world wide
Rinderpest
You go to a piggery and see some of the piglets
huddling together. You notice cyanosis and erythematous lesions on the huddling piglets.
What is the first disease on your differential list?
Classical Swine Fever
(Pestivirus)
What is the incubation period of African Swine Fever?
5 - 19 days
Picornaviridae, which is antigenically related to human
coxsackievirus B5, causes this disease
Swine Vesicular Disease (SVD)
FMD is ____ severe than SVD in pigs
FMD is MORE severe than Swine Vesicular Disease
This disease affects cows and has an incubation period of 2 to 8 years with 100% mortality rate
BSE
How is Newcastle Disease transmitted?
Direct contact with feces or respiratory secretions
or
Indirect contact with feed, water, equipment, or human clothing
A chicken farmer has noticed that his hens are not producing as many eggs as normal. All of a sudden, almost 1/2 his flock dies off, over a course of two days and a few more die throughout the rest of the week.
Now, some of the birds are walking funny and can’t keep their balance (neuro signs).
What is causing this chicken die-off?
Newcastle Disease
Which subtypes of LPAI can mutate into HPAI?
H5 or H7
What surface antigen is responsible for attachment
for Influenza A Bird Flu?
Hyaluronidase
Which surface antigen is responsible for viral release
for Influenza A Bird Flu?
Neuraminidase
What is the most common clinical sign in humans
infected with HPAI?
Conjunctivitis
Asymptomatic domestic ducks are the asymptomatic reservoirs of this strain of influenza, which causes
pneumonia and high fatalities in humans?
H5N1 (Bird Flu)
