2-Zoonoses: Aerosol & Respiratory Transmission Flashcards
Do enzootic bacterial “category A” agents have one route of infection or multiple routes of infection?
What makes them potential bioweapons?
- Multiple routes of infection.
- Their aerosol potential makes them “bioweapons”.
What are 3 examples of enzootic bacterial “category A” agents?
- Bacillus anthracis
- Yersinia pestis
- Francisella tularensis
What is a cosmopolitan intracellular bacterium that affects humans and animals?
Francisella tularensis
What are 3 species that can be affected by Francisella tularensis?
- Humans
- Domestic cats
- Sheep
What is the primary, long-term reservoir of Francisella tularensis?
Rodents and lagomorphs (“rabbit fever”)
How is Francisella tularensis transmitted in sheep?
Usually tick-borne
How is Francisella tularensis transmitted in cats?
Usually from eating infected rodents.
How is Francisella tularensis transmitted in people?
Most often tick or direct contact with animals/carcasses, aerosol exposure less often.
Are urban human cases of Yersinia pestis rare or common?
Rare so long as there is aggressive rodent control.
Infected domestic animals can serve as a “bridge” between what?
Wildlife and human populations.
What is the primary cycle of the plague?
Rodent-flea-rodent
What are 6 examples of potential hosts for the plague?
- Squirrels
- Prairie dogs
- Mice
- Wood rats
- Chipmunks
- Rats
How many different species of flea are competent vectors for the plague?
31
What is the most common flea vector of the plague?
Xenopsylla cheopis (oriental rat flea)
Which species is susceptible to the plague and can infect people?
Cats
When are cats usually exposed to the plague?
While hunting/eating rodents.
What are 2 examples of predators that can be infected by the plague?
- Cougars
- Birds of prey
With the plague, coyotes and dogs seroconvert but are rarely what?
ill
What are 3 ways people can be infected by the plague?
- Flea bite
- Aerosol from pneumonic cases of plague
- Directly from infected animal blood or abscesses?
What is the most common way people can be infected by the plague?
Directly from infected animal blood or abscesses.
Cats that are allowed to do what can be exposed to the plague and tularemia?
Forage outside
The bacteria that cause both plague and tularemia can cause localized infection followed by what 3 things?
- Sepsis
- Endotoxemia
- Pneumonia
What might the plague cause at the site of skin entry?
A necrotic eschar
Which can cause lymphadenopathy of draining lymph nodes, the plague, tularemia or both?
Both
Pulmonary involvement in the plague and tularemia can lead to what?
Aerosol spread
What are 5 clinical signs associated with the plague and tularemia that can be seen in cats?
- Fever
- Lethargy
- Anorexia
- Sepsis
- Lymphadenopathy often located in the cervical region
Do the plague and tularemia progress slowly or rapidly?
Rapidly
What are 2 clinical signs that can be seen with the plague and tularemia that are considered to be poor prognostic indicators?
- Pneumonia
- Septic shock
Are the clinical signs and progression seen with the plague and tularemia in people similar or different from those seen in cats?
Similar
Are plague eschars easier or harder to see on people?
Easier, no fur.
High fever and high case fatality rate are seen in what kind of plague or tularemia cases?
What else can be seen with these cases?
- Septic/pneumonic cases
- Circulatory collapse with blackened extremities
T/F: Lymph node aspirates are highly infectious in the plague and tularemia.
True
Is isolation a good idea when dealing with the plague and tularemia?
Yes
What does PPE stand for in epidemiology?
What are 2 examples of PPE?
- Personal protective equipment
- gloves and masks
What is the spore-forming bacterium that causes anthrax?
Bacillus anthracis
How long can Bacillus anthracis survive in the soil?
Under good conditons for years.
What species can be affected by anthrax?
Most mammal species
How is anthrax transmitted to herbivores?
Ingest spores in soil while grazing.
How is anthrax transmitted to carnivores?
Eat infected herbivores.
What are two forms of transmission that can affect all species?
- Inhalation of spores in aerosolized soil
- Contaminated fomites
“Wool sorter’s disease” is associated with which bacterium?
Bacillus anthracis
What are 2 ways veterinarians can contract anthrax?
- Aerosol
- Percutaneous exposure to blood from infected animals
Most veterinary cases of anthrax are seen in what species?
Cattle
What are 2 things that can be caused by Bacillus anthracis spores as they enter the host?
- A necrotic eschar at skin entry point.
- Causes atypical pneumonia if inhaled.
Once the spores “germinate” they can cause what?
Sepsis
What are 3 things that the exotoxins of Bacillus anthracis can cause?
- Massive edema
- Shock
- Death
With anthrax, death often follows what?
DIC
What are 5 examples of postmortem signs of anthrax in cattle?
- Blood not clotted
- Spores in blood on microscopy
- Rapid bloating
- Lack of rigor mortis
- Blood from orifices
What is an enveloped ssRNA virus seen in the family Bunyaviridae?
Hantavirus
Is Hantavirus seen world-wide?
Yes
Individual species are typically limited to a specific reservoir host and geographic region with what virus?
Hantavirus
What is the reservoir for Hantavirus?
Rodents
Are rodents carrying Hantavirus symptomatic?
No, usually asymptomatic
What are 3 ways rodents shed hantavirus?
- Saliva
- Urine
- Feces
What is the primary mode of transmission of hantavirus?
Aerosol: inhalation of virus in urine or feces
How long can hantavirus survive in most bedding under cool conditions?
Weeks
Is hantavirus susceptible to desiccation?
Yes
Can transmission of hantavirus direct, indirect or both?
Both
What is a form of secondary transmission of hantavirus?
Bite
What does the severity of the clinical signs seen with Hantavirus depend on?
Species of virus
What does HPS stand for?
Hantavirus Pulmonary Syndrome
What are the US strains of hantavirus known as?
The “new world” disease
What are 5 clinical signs seen with Hantavirus Pulmonary Syndrome?
- Fever
- Chills
- Myalgia
- Headache
- Increased vascular permeability in the lungs
Hantavirus is fatal in what percentage of human cases?
Up to 40%
What does HFRS stand for?
Hemorrhagic Fever with Renal Syndrome
What is HFRS referred to as?
The “old world” disease
What are 3 clinical signs seen with Hemorrhagic Fever with Renal Syndrome caused by hantavirus?
- Petechial hemorrhage
- Renal damage
- Cardiovascular shock
HFRS is fatal in what percentage of cases?
Up to 15%
What are 2 potential risk factors for hantavirus?
- Increased rodent density
- People who work with rodents or rodent habitats
What are 2 ways to reduce human exposure to hantavirus?
- Face masks
- Gloves
What are 3 examples of causes of infections from spores in the environment that becomes aerosolized and are inhaled?
- Saprophytic soil fungi
- Blastomyces
- Cocciciodes
Birds and bats can be reservoirs for what 2 fungi?
- Histoplasma
- Cryptococcus
Are humans, dogs, cats infected with Blastomyces, Coccidiodes , Histoplasma or Cryptococcus infectious?
No, body temperature is too high for sporulation of these fungi.
Acute fungal pulmonary infections can have what 4 clinical signs?
- High fever
- Night sweats
- Enlarged pulmonary lymph nodes
- Radiographic masses
What might happen if the immune system fails to control a fungal pulmonary infection?
Progresses to chronic infection and spread to other tissues.
What is the reservoir for Coccidioides immitis?
Soil
What are 5 species Coccidioides immitis infects and amplifies in?
- People
- Dogs
- Cats
- Cattle
- Horses
Signs of Coccidioides immitis can range from what to what?
From asymptomatic to disseminated.
Where are 2 reservoirs for Histoplasmosis?
- Soil
- Buildings with bird feces or bat guano
What are 3 species affected by Histoplasmosis?
What percentage are asymptomatic?
- People, dogs, cats
- About 90%
What is the reservoir for Blastomyces dermatitidis?
What is it also associated with?
- Soil
- Bird and bat feces
What are 4 species that can be affected by Blastomyces dermatitidis?
Greater than 50% can be asymptomatic in what species?
- People, dogs, cats, horses
- People
What are 6 examples of influenza?
- Avian flu
- Bird flu
- Foul plague
- Fowl pest
- Swine flu
- Canine flu
What virus family is Influenza found in?
Orthomyxoviridae
What are the 3 distinct types of influenza?
A, B, C
Which 2 strains of influenza have been circulating since 1977?
- H1N1
- H3N2
What are 4 main species affected by influenza?
- Birds
- Swine
- Horses
- Dogs
Animal to human transmission of influenza is only documented for what 2 species?
- Birds
- Swine
Influenza B is seen in what 2 species?
- Humans
- Seals
Is influenza C common or rare?
Rare
T/F: Influenza viruses undergo continuous mutation resulting in different strains each season.
True
What are 2 categories of avian influenza?
- Low pathogen (LP)
- High pathogen (depending on lethality to chicken)
On what 3 continents is H5N1 circulating?
- Asia
- Europe
- Africa
What are 3 other HP avian influenza viruses that have been related to previous outbreaks?
- H7N7
- H7N3
- H5N2
Is influenza found worldwide?
Yes
What are 6 examples of wild bird host reservoirs seen with avian influenza?
- Ducks
- Geese
- Swans
- Gulls
- Ferns
- Shorebirds
Swine are susceptible to strains in what other 2 species?
- Humans
- Avian
How is influenza transmitted between people?
- Direct contact (person to person)
- Indirect contact (contaminated surface)
What are 2 ways influenza is transmitted among swine?
- Direct
- Aerosolization
What are 3 ways influenza is transmitted among wild birds?
- Fecal-oral
- Saliva
- Nasal secretions
What are 4 methods of transmission of influenza seen in poultry?
- Direct
- Contaminated surfaces
- Feed and water
- Aerosol
What are 3 ways influenza is transmitted from animals to humans?
- Contaminated surfaces
- Manure Handling
- Dust
What are 3 risk factors for transmission of influenza?
- High bird/pig density
- Mixing of many species in one area
- Farms with water bodies
What are 6 clinical signs of influenza seen in humans?
- Fever
- Myalgia
- Headache
- Malaise
- Sore throat
- Cough
What are 2 areas of the body affected in LP avian influenza?
- Upper respiratory
- Reproductive organs
What are 3 clinical signs seen with HP avian influenza?
What does this lead to?
- Lethargy, facial edema, cough
- High mortality and sudden death
What are 4 clinical signs seen with swine influenza?
- Fever
- Coughing
- Nasal discharge
- Reproductive problems
What morbidity and mortality rates are seen with swine influenza?
- Morbidity: 100%
- Mortality: low
What could lead to a high mortality with swine influenza?
Secondary bacterial infection
What is an influenza treatment seen in humans?
Antiviral (Tamiflu)
What is the treatment of influenza used with animals?
Generally supportive
Are antivirals approved for use in animals?
No, fear of resistance.
If a case of avian influenza is suspected or found positive, who should be contacted?
State veterinarian
What type of personal protective equipment should be worn with highly pathogenic suspects?
N-95 respirators (masks), gloves
What are 2 things to do with sick animals?
- Test
- Isolate
What needs to be done with owners concerning zoonotic risk?
They need to be educated.
What are 2 groups of people who should get annual seasonal vaccines?
- Vets
- Farm workers
What are 2 groups of animals that should get vaccinations?
- Livestock
- Poultry
What is another name for Q-fever?
Abattoir fever
What causes Q-fever/abattoir fever?
Coxiella burnetti
What are 6 examples of host species for Coxiella burnetti?
- Sheep
- Cattle
- Goats
- Birds
- Dogs
- Cats
Does Coxiella burnetti have a low or high infectivity rate?
High
Is Coxiella burnetti able to survive in the environment?
Yes
What are the 2 morphologic forms of Coxiella burnetti?
- Large and bacilliform
- Small high density form (spore-like)
What are 3 groups particularly at risk for contracting Q-fever/abattoir fever?
- Slaughterhouse personnel
- Vets
- People working with pregnant animals especially sheep
What are 5 ways Coxiella burnetti can be transmitted?
- Wind borne in dust
- exposure to parturient cats
- Shed in birth products (esp. sheep), milk
- Lower shedding in feces and urine
- Tick borne (mainly animals to animals)
What are 5 clinical signs that can be seen in humans with Q-fever/abattoir fever?
- Fever
- Malaise
- Chills
- Sweats
- Headache
What is the incubation period for the acute form of Q-fever/abattoir fever?
2-3 weeks
What are 2 clinical signs seen with cattle, sheep and goats with Q-fever?
- Anorexia
- Abortion
If Q-fever is suspected, what 3 things should be done immediately?
- Seek medical attention.
- Segregate parturient animals.
- Burn placentas and other reproductive organs.
What are 2 things that should be done to help control Q-fever?
- Follow proper bio safety procedure
- Vaccinate livestock
What does Chlamydophilia psittaci cause in birds?
In humans?
- Birds: Avian chlamydiosis
- Humans: Psittacosis, Chlamydiosis, Parrot fever
What are the 2 forms of Chlamydiosis?
- Infectious elementary body (very stable in environment)
- Non-infectious reticulate body
What are 4 examples of groups at risk of getting Chlamydiosis?
- Bird owners
- Pet store workers
- Vets
- Poultry and poultry processing
What species of birds does avian chlamydiosis occur most commonly in?
What other species can it occur in?
- Psittacine birds (parrots, cockatiels)
- Domestic poultry
What is the main mode of transmission of avian chlamydiosis in birds?
Fecal-oral
What is the main mode of transmission of Psittacosis in humans?
Direct handling of infected birds.
What are 5 clinical signs associated with the acute febrile syndrome seen with Psittacosis in humans?
- Headache
- Myalgia
- Cough
- Shortness of breath
- Photophobia
What are 5 possible complications that can be seen with human Psittacosis?
- Hepatitis
- Endocarditis
- Myocarditis
- Pericarditis
- Nephritis
What can Chlamydophilia psittaci cause in animals?
Morbidity and mortality in psittacine birds.
What are 3 ways to help control the spread of Chlamydophilia psittaci?
- Counsel pet bird owners on signs of parrot fever.
- Consider disease in amy sick bird with lethargy and non-specific signs especially if stressed.
- Biosafety measures in handling infected birds (gloves, mask,)
