Flashcards in Zoonoses Deck (62)
what is the CDC definition of zoonoses
contagious diseases spread between animalss and humans
how are humans involved in the life cycles of zoonotic diseases?
they are accidental hosts, not part of the life cycle
what is a reservoir? do they show signs of infection?
non human species that maintains the infection. may or may not show clinical symptoms
what is a vector?
an organism that transmits the pathogen from reservoir to other animals. not required for transmission
what are three transmission routs of a zoonosis?
contact with infected material from an animal, bite by a vector or eating or drinking infected material
what are five bacterial zoonotic pathogens?
bacillus antracis, francisella tularensis, brucella, yersinia pestis, and bartonella henselae
what is the vector of B anthracis?
no vector usually
what are the vectors of F tularensis?
ticks, mosquitos and deer flies
what are the hosts for b anthracis? what disease does it cause?
cattle and other ungulates. causes anthrax
what is the life cycle of b anthracis?
the cattle inhale spores from the soil that germinate once ingested and ultimately kill the host
how are humans exposed to anthrax?
they are exposed to spores from the environment or contaminated animal products
what are the hosts of yersinia pestis? what are the vectors? what disease does it cause?
causes the plague
how is y. pestis transmitted to humans?
most commonly from an infected flea bite or contact with an infected rodent
what are the hosts and vectors of type A tularaemia?
lagomorphs (rabbits and hairs) are the hosts and ticks and flies are the vectors and long term reservoirs
how are patients infected with type A tularaemia?
by the bite of an infected vector or by handling a diseased animal. also can inhale dust or aerasols contaminated during farming or landscaping
what are the hosts of francisella tularensis holarctica? vectors? long term reservoirs?
hares, rabbits and beavers
vectors include mosquitoes, tabanid flies and ticks
ticks are also reservoirs
how are mammals infected by f. tularensis holarctica?
by drinking infected water
how are humans invected with tularemia type B?
by contact with infected host or vectors and by ingestion of infected water
what are the three types of anthrax poisoning?
cutaneous-creates dark sores on the skin
inhalation and GI infection
what is the form of bacillus anthracis?
gram positive rod
what does cutaneous anthrax infection look like?
small sore that develops into a blister and then into a skin ulcer with a black area in the center. it does not hurt but there is edema
what are the GI symptoms of anthrax?
nausea, bloody diarrhea, fever and stomach pain
what are the pulmonary symptoms of anthrax?
cold/flu symptoms. later symptoms include cough, SOB and muscle aches
how is anthrax treated?
with cipro or doxycyclin
what regions do the different tularemia strains inhabit?
type A (more virulent) in US and canada
type B (less virulent) in Europe and Asia
what is the morphology and metabolism of tularemia?
aerobic gram negative rod
what is the most common form of tularemia?
ulceroglandular- a skin ulcer appears where the organism entered the body and regional lymph nodes swell
what is glandular tularemia?
no ulcer appears but there is regional lymphadenopathy
what is oculoglandular tularemia?
occurs when bacteria enter through the eye - irritation and inflammation of the eye and swelling of lymph nodes around the ear