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56 Cards in this Set
- Front
- Back
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What are the zoonotic intracellular organisms that travel to target organs inside phagocytes?
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F. tularensis (tularemia)
Brucella spp. (brucellosis) C. burnetii (Q fever) |
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A farmer presents with endocarditis. What are you worried about?
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Chronic Q fever due to Coxiella burnetii
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What zoonotic bacteria forms spores that will persist in the environment (usually in the afterbirth of affected animals that aborted fetus)?
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C. burnetii (Q fever)
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What two zoonotic bacteria are often cross-reactive on serology?
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F. tularensis (tularemia) and Brucella spp. (brucellosis)
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For which bacteria can you differentiate acute and chronic disease with serology bc of antigenic variation?
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C. burnetii (Q fever) --- phase I and phase II antigens distinguishable
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What is streptomycin the drug of choice for (zoonotic)?
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Y. pestis (plague)
F. tularensis (tularemia) |
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What is doxycycline the drug of choice for (zoonotic)?
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Brucella spp. (brucellosis)
C. burnetii (Q fever) |
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Besides abscesses and cellulitis due to P. multocida and capnocytophaga, what are 4 diseases that someone can get from a cat bite?
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pneumonic plague
Cat Scratch Fever (B. henselae) Toxoplasmosis Rabies virus |
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What are three ways to get toxoplasmosis?
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Fecal-oral route (cat feces)
Eating undercooked meat of intermediate host Transplacental |
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You see cytoplasmic inclusion bodies on a post-mordem DFA. What did the patient die of?
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Rabies
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You see hydrophobia and behavioral changes in a child. The parent indicates that they noticed him itching his arm a week ago. What is this and in what stage?
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Rabies
Neurologic period (was in prodromal period when had itchy arm) |
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What zoonotic disease affects young, healthy people in the Western U.S.?
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Sin Nombre virus (or other Hantaviruses)
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What are two zoonotic organisms not spread person-to-person?
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Brucella spp (brucellosis) -- gram neg coccobacilli
Hantavirus |
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For what diseases is animal vaccination the best prevention?
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Brucellosis
Rabies |
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You see gram-neg extracellular "safety pins" on culture. What are you looking at?
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Y. pestis (plague)
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What are the two major (and one minor) virulence factors of Y. pestis and what is a feature of them that limits their virulence?
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Yops (interrupts phagocytosis)
LcrV (translocates Yops, delays inflammatory response) F1 is the minor one They are activated at body temp so if obtained in inactive form (e.g. urban cycle via flea on rat, then must hide in macrophage from immune system before it can be activated or will be eliminated) |
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What zoonotic diseases are seen more often in the Western U.S.?
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Y. pestis (plague)
Brucellosis Hantavirus |
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What two animals can spread the pneumonic plague in respiratory secretions?
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Humans and cats
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What animals spread the plague via the urban cycle? Via the sylvan cycle?
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Fleas on rats via urban cycle
Squirrels or prarie dogs via sylvan cycle |
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Patient presents with sudden chills, fever, headache, nausea, vomiting. A day or two later patient gets lymphadenitis - specifically, buboes in the inguinal region. What does the patient have and when will the disease start to become systemic?
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Bubonic Plague
A day or two after the lymphadenitis. |
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Patient had contact with a sick person 2-3 days ago, and now has flu-like symptoms and chest pain. What is causing the lung disease and what is the mortality rate if untreated?
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Endotoxin
100% mortality without treatment (pneumonic plague) |
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How is septicemic plague obtained and what is its progression?
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Obtained from a flea bite, lymph nodes are bypassed so goes straight from location of bite --> septicemic phase --> vasculitis --> gangrene
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What is pestis minor?
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A form of the plague that stays localized to the flea bite and causes necrosis but is not life-threatening
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What is the drug of choice for the plague?
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Streptomycin
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You see a gram-neg coccobacilli growing on chocolate agar (requires oxygen, cysteine, and a prolonged incubation time). What is this and what 3 vectors are common carriers of it?
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F. tularensis
Tularemia is often spread by ticks, the deerfly, and especially RABBITS May also be brucellosis.... |
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Hunter from Martha's Vineyard presents with a large ulcer eating through multiple layers of skin. What is the likely disease and what is the best test for diagnosis? How is it treated?
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Tularemia
Order serology and confirm with culture on chocolate agar (alert lab, needs prolonged incubation time) Treat with streptomycin. |
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What can you get from consuming unpasteurized milk?
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Brucellosis
Q Fever (this is what they target when they pasteurize) |
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What is a disease you can get worldwide from contact with hooved animals? What is the incubation period and symptoms of acute disease?
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Brucellosis
Incubation up to 2 months, acute disease is flu-like symptoms |
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When does chronic brucellosis set in and what are the symptoms?
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Can be years after initial infection
Sxs include arthritis, GI symptoms, orchitis, endocarditis --> this is all due to granulitis |
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What is the treatment for brucellosis?
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6 wk course of doxycycline and rifampin
If this is contraindicated, give Bactrim. |
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What two organisms form spores that help it spread by being resistant to environmental degradation?
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C. burnetii (Q fever)
T. gondii (toxoplasmosis) |
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What is the infective stage of toxoplasma gondii? How is it spread?
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Oocyst, spread in cat feces and picked up by either a human or another animal, where it hides in macrophages and produces tachyzoites that reproduce in adjacent tissues and creates a tissue cyst (in bradyzoite stage) that is usually inactive unless immune system becomes compromised (humans can also get it by eating an animal with a tissue cyst that has been undercooked) at which point tachyzoites are released
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What are the symptoms of toxoplasmosis in an immunocompetant host?
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Asymptomatic, mild flu-like symptoms, cervical lymphadenopathy
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What are the symptoms of toxoplasmosis in an immunocompromised host?
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Toxoplasma encephalitis most common with reactivation toxoplasmosis.
If get a primary infection when immunocompromised, get severe and widespread disease. This is often fatal, especially with primary infection. |
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What are the symptoms of congenitally-acquired toxoplasmosis?
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Microencephalitis, hydrocephalus, seizures, jaundice, chorio-retinitis.
More severe the earlier the infection happens. |
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If serology is used to diagnose toxoplasmosis in an immunocompetant person, what indicates current infection? Past infection?
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Current=IgM
Past=IgG |
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What treatment is given to a pregnant woman who may have acquired toxoplasmosis?
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Spiramycin and clindamycin
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What treatment do you give an immunocompromised person who has toxoplasmosis?
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Sulfadiazine and pyrimethamine or bactrim
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What do you give in adjunct with drug treatment to someone who has cerebral edema or eye infections due to toxoplasmosis?
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Corticosteroids
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What type of virus causes rabies?
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Rhabdovirus (-RNA, enveloped), 5 proteins coded for
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What are four ways to get rabies?
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Bite of infected animal
Inhalation (bat caves) Organ transplants Direct contact with mucous membranes of affected animal |
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What is the progression of the spread of the rabies virus?
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Replicates in muscle where bite happened the moves up the peripheral nerve towards the CNS. Once it reaches the spinal cord it rapidly gets up to the brain and can cause encephalitis then disseminates out to other organs via the nerves (esp the salivary glands) so that it can infect others
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Are antibodies effective against Rhabdovirus?
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Yes but the virus is not cytolytic so by the time antibodies are made against it it is usually already in the CNS and the response is too little, too late
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What are two things that can make the incubation period of rabies shorter in the 5 days to 2 years range?
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If the bite happened closer to the CNS and if it is deeper
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In what period is the PEP (post-exposure prophylaxis) for rabies effective?
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Incubation period (before the virus reaches the CNS)
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What 4 specimens are needed by the CDC in order to make an antemordem diagnosis of rabies?
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Neck biopsy
CSF Saliva sample Serum sample |
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What is the treatment for rabies in later stages of the disease (neurologic period)?
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Supportive care, sedation (put them in a coma), interferon, immune globulins for rabies, ribavarin and amantidine
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What family of viruses are the hantaviruses in?
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Bunyaviridae
-RNA |
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What is the most common Hantavirus in the U.S.?
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Sin nombre virus
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A week after nonspecific flu-like symptoms and abdominal pain starts, a young adult from New Mexico develops shortness of breath and hypoxia that you determine is related to pulmonary edema. What test do you order to try to make the diagnosis and what treatment are you likely to have to give?
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Either serology, immunohistochemistry, or PCR
Will likely have to intubate and put on vent (this is a hantavirus such as Sin Nombre virus which is spread by the deer mouse) |
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Describe the type of virus that causes Ebola.
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Flavivirus (filamentous -RNA)
4 strains exist (Zaire, Sudan, Ivory Coast, Reston) |
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Which strain of Ebola has the highest mortality rate and what is it?
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Zaire (90%)
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How are the three strains of Ebola that are most deadly to humans spread?
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Direct contact
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Patient presents with flu-like symptoms, then nausea, vomiting and diarrhea. Soon after, petechia and ecchymoses are noted (due to coagulopathy) and then hemorrhage and shock are observed. Patient also has neurological disturbances. What is this?
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Ebola or Marburg
Highly infectious, biosafety level 4 |
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What is the suspected natural reservoir for Ebola and Marburg?
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Bats and/or monkeys
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What is the mortality rate of Marburg and how is it spread?
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25%
Direct contact |
