Zoonoses: Aerosol/Respiratory Flashcards Preview

RUSVM Epi Summer 17 > Zoonoses: Aerosol/Respiratory > Flashcards

Flashcards in Zoonoses: Aerosol/Respiratory Deck (59)
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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?



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?


(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?


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)

1. blood not clotted
2. spores in blood on microscopy
3.rabid bloating
4. lack of rigor mortis
5.blood from orifices



Who is the reservoir of Hantavirus?


*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?


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