Zoonoses: Aerosol/Respiratory Flashcards
What makes a bacterial pathogen fit into the “Category A” agents?
These all have MULTIPLE routes of infection. Their aerosol potential makes them BIOWEAPONS but veterinary risks are more diverse and include necropsy and tx of animals
What bacterial pathogens are category A agents?
Bacillus anthracis
Yersina pestis
Francisella tularensis
What domestic animal are humans most likely to get Tularemia from?
CATS
Who are the long term reservoirs of F. tularensis?
Rodents and lagomorphs
What are the routes of transmission of F. tularensis?
Tickborne (common in sheep)
Ingestion (cats ingesting infected rodents)
People - most often get it from ticks or direct contact with animals/carcasses; aerosol exposure is less common
What animals serve as the bridge for Yersina pestis between wildlife and human population ?
Infected domestic animals - often cats
What animals/vectors are involved in the primary cycle of Y. pestis?
Rodent-flea-rodent
31 species of flea are competent vectors
How can people be infected with Y. pestis?
flea bite
aerosol from pneumonic cases
Directly from infected animal blood or abscesses
What clinical signs will you see in cats with either plague or tularemia?
local infection followed by sepsis –> endotoxemia–> pneumonia
Lymphadenopathy of draining LN (often in cervical region), fever, lethargy, anorexia, sepsis
What symptoms will you see in humans with tularemia or plague?
*plague eschars - areas of bacteria entry - necrosis
Both: high fever and high fatality in pneumonia and septic cases
Circulatory collapse with blackened extremities
What cautions should be taken when dealing with a potentially infected cat?
Lymphnode aspirates are highly infections - wear proper PPE
Isolation for the animal
PPE for the vet and staff at during any encounter with the animal: gloves, mask, +/- mucous membrane protection
How long can Bacillus anthracis survive in soil? Why?
it is a spore forming bacterium that can survive in the soil under good conditions for years
How do herbivores and carnivores get anthrax?
Herbivores ingest spores in the soil while grazing
Carnivores eat infected herbivores
*all species: inhalation of spores in aerosolized soil or other contaminated fomites
What are the most common way veterinarians could get anthrax?
Aerosol or percutaneous exposure to blood from infected animals
**most veterinary cases are seen in cattle **
What process do anthrax spores undergo when they enter the bloodstream?
They germinate –> cause sepsis
In cattle infected with anthraz, death will often follow what syndrome? How can you tell?
DIC
The carcass will have un-clotted blood seeping from the orifices
Which of the following are PM signs of anthrax in cattle? (more than one may apply)
- blood not clotted
- spores in blood on microscopy
- rabid bloating
- lack of rigor mortis
- blood from orifices
ALL OF THEM
Who is the reservoir of Hantavirus?
rodents
*typically sylvatic but can also infect some pet rodents
How do rodents shed hantavirus?
saliva, urine, feces
What is the primary mode of transmission of Hantavirus?
Primarily aerosol
*inhalation of viruses in urine or feces
Transmission can be direct or indirect - secondary transmission through bite
What determines the severity of dz due to Hantavirus?
The species of virus
What is the “new world” disease caused by Hantavirus?
Hantavirus Pulmonary Syndrome (HPS)
*USA strains of the virus
Starts as fever, chills, myalagia, headache.. increased vascular permeability in the lungs
*fatal in 40% of human cases
What is the “old world” disease caused by Hantavirus?
Hemorrhagic Fever with Renal syndrome (HFRS)
Petechial hemorrhage, renal damage, and cardiovascular shock
*fatal in up to 15% of cases
What are the risk factors to contracting Hantavirus?
Human-rodent contact
- increased rodent density
- rodents living in barns or buildings
- people who work with rodents or rodent habitats
How do you prevent contracting Hantavirus?
Reduce human exposure. Wear proper PPE when dealing with rodents or their habitats (face mask and gloves)
How are humans exposed to fungal pulmonary infections?
Infections from spores in the environment become aerosolized and are inhaled
What are two saprophytic soil fungi that have the potential to cause fungal pulmonary infections in humans?
Blastomyces and Coddidiodes
*birds and bats can be reservoirs - fecal excretion = soil contamination
What are two opportunistic fungi that can cause fungal pulmonary infections in humans?
Histoplasma and Cryptococcus
Spores in soil or in bird bedding/feces
Are humans and animals with fungal pulmonary infections infectious?
NO
The body temperature is too high for sporulation of these fungi
*could be a risk post mortem potentially
What symptoms are seen in a patient with an acute fungal pulmonary infection?
Often pneumonia like - due to inflammation
High fever, night sweats, enlarged pulmonary LN, Radiographic masses
**if the immune system fails - disseminated infection can occur and spread to other organs
What is the reservoir of Coccidioides immitis?
SOIL
Where does Coccidioides immitis amplify?
People, dogs, cats, horses, etc
*deceased animals may spread fungus to new areas of soil
Where is histoplasmosis found?
In soil or buildings with bird feces or bat guano present
*increased risk for pigeon handlers and farmers using chicken feces for manure
Who does histoplasmosis affect and what percentage of those infected are symptomatic?
people, dogs, cats
~10 % will be symptomatic
Blastomycers dermatitidis is a ______ fungus that is associated with the feces of _______ and ________
soil
birds
bats
*affects people, dogs, cats, horses, etc etc
What family is the zoonotic influenza virus a part of, and what are other names for it?
Family: Orthomyxoviridae
avian flu, bird flu, foul plague, swine flu, canine flu, etc
How many distinct types of zoonotic influenza are there? How are they categorized?
3 distinct types: A, B, C
Influenza A antigens: have haemaglutinin and Neuraminidase surface glycoproteins
What species are affected by Influenza A antigens?
Birds, swine, horses, and dogs mainly
Animal to human transmission of influenza is only documented for ______ and ________ (what animals?)
Birds and swine
T/F: Influenza C is quite common
FALSE
it is rare
Who gets infected with influenza B?
Humans and seals
human morbidity is documented each year
Swine are considered a _____ vessel, because they are susceptible to both the ____ strain of influenza and the ________ strain of influenza
Viral Mixing Vessel
Human and Avian strains
What are the modes of transmission of zoonotic influenza?
Between people: direct and indirect (contaminated surfaces)
Swine: direct and aerosolization
Wild birds: Fecal oral, saliva, nasal secretions
Poultry: direct, contaminated surfaces, feed, water, and aerosol
Animals - human: contaminated surfaces, manure handling, dust
What clinical signs are seen in birds and swine with influenza?
Avian: mostly low pathogenic strains: Upper respiratory and repro organs are affected. High pathogenic stains - lead to high mortality and sudden death; lethargy, facial edema, cough
Swine: fever, coughing, nasal dc, repro problems. Morbidity 100% but low mortality.
*mortality increased with secondary infections
What symptoms are seen in humans with influenza infection?
Fever, myalagia, headache, malaise, sore throat, cough
*age and immune-compromised factors will increase severity
Are antiviral medications used in birds or swine with influenza?
NO
fear of resistance
*only humans will get antivirals
What are some methods of control and prevention of influenza?
*Contact state vet in suspect or positive cases of avian influenza
*Wear appropriate PPE
Test and isolate sick animals
*Educate owners
*Annual seasonal vaccines for vets and at risk groups like farm workers
*Vaccination of livestock and poultry
What people are most at risk for contracting Q fever?
Slaughterhouse personnel
vets
(especially people working with pregnant sheep)
What are the two morphological forms of C. burnetti?
Large and bacilliform
small density form (spore like)
What are the modes of transmission of C. burnetti?
Windborne in dust exposure to parturient cats Shed in birth products - especially sheep shed in milk Lower shedding in urine and feces *tick borne - mainly animal to animal
What symptoms will you see in a person with Q fever?
Fever, malaise, chills, sweats, headache
What clinical signs will you see in cattle/sheep/goats with C. burnetti?
Anorexia and abortion
What should be done to control C. burnetti?
- immediately seek medical attention if suspected
- segregate parturient animals and burn placentas and other reproductive discharges
- proper bio safety procedures
- vaccinate livestock
What people are most at risk for Psittacosis or chlamydiosis?
Bird owners, pet store workers, vets, poultry and poultry processing personnel
Chlamydophilia psitacci occurs mostly in what birds?
Psittacine birds - parrots
also occurs in domestic poultry
What are the routes of transmission of C. psitacci?
Birds: fecal-oral
Humans: direct handling of infected bird
What symptoms will you see in a human infected with C. psitacci?
Acute febrile syndrome: headache, myalgia, cough, shortness of breath, photophobia.
Complications include - hepatitis, endocarditis, myocarditis, pericarditis, nephritis
What clinical signs do you see in birds with C. psitacci?
Can cause morbidity and mortality in psittacine birds
How do you control C. psitacci?
- counsel bird owners on signs of parrot fever
- consider disease in any sick bird with lethargy and non specific signs - especially if stressed
- biosafety measures in handling infected birds (PPE)
