exam V pathogens Flashcards

Question

coccidioides: disease

Answer 1

valley fever: acute self-limiting pneumonia

Answer 2

- non-dimorphic, opportunistic pathogen - normal flora, transmitted by breach of mucocutaneous barrier - bloodstream infection after IV, implanted devices, HIV pts at risk

Answer 3

- ID by KOH stain, culture - treated w/ nystatin

Answer 4

- pseudomembrane: white plaque on buccal mucosa, palate, tongue - atrophic form: erythema, no plaque - cotton mouth

Answer 5

- esophageal candidiasis (painful swallowing, substernal chest pain) is HIV-defining - candidemia (HIV and ICU patients)

Answer 6

- opportunistic, has dual life cycle between haploid and diploid - reservoir is humans, transmitted by infected humans - risk to HIV patients (life-threatening)

Answer 7

- cell membrane does not have ergosterol --> resistant to standard fungal treatments - treat w/ TMP-SMX

Answer 8

- staining, visualization of cup shaped cyst - ground glass opacity on CT scan

Answer 9

- treated w/ fluconazole and amphotericin B - ID by antigen test

Answer 10

- common mold - transmitted by inhalation

Answer 11

- invasive infection: not enough immune response causes aspergillosis (pneumonia, sinusitis by hyphae invading tissue) - colonization: too much immune response leads to mast cell degranulation, eosinophilia

Answer 12

- ABPA needs glucocorticoid for allergy, itraconazole for fungus - aspergillosus is treated w/ voriconazole, sometimes amphotericin B

Answer 13

- CT scan of lungs, sinuses: ground glass infiltrates, fungus ball in lungs - biopsy, culture, histology: hyphae w/ acute branching angle

Answer 14

- ubiquitous - transmitted by inhalation or trauma - more of a risk to immunosuppressed, diabetics (like acidic environment/high glucose for growth)

Answer 15

- right angle branches and ribbon-like hyphae - treated w/ surgical debridement

Answer 16

- diabetics more at risk - inoculation of sinuses - progresses to surrounding areas, leads to black eschar in affected regions

Answer 17

- central dermal necrosis - red/purple edematous cellulitis - mold may be visible

Answer 18

- pneumonia w/ infarction, can disseminate to heart (chest pain, hemoptysis) - less common in diabetics

Answer 19

- humans are only reservoir that excrete amoebic cysts - fecal-oral transmission - more likely in mexico, central america, areas w/ poor sanitation/sewage systems

Answer 20

- cyst is ingested - trophozoites are released in intestines in response to gastric acid - invade colon, replicate - encyst again

Answer 21

- ID in stool sample: can see ingested RBCs within trophozoites - treated w/ metronidazole

Answer 22

- caused by entamoeba histolytica - can be asymptomatic or cause watery diarrhea - gradual onset - rare: toxic megacolon, liver abscess w/o jaundice

Answer 23

- found in many mammals, beavers - transmitted by ingestion of cysts in contaminated water, fecal-oral - risk to backpackers, kayakers, developing nations. most common 3rd world water infection

Answer 24

- exists in environment as quadrinucleate cyst - trophozoites are active - trophozoites passed in stool, encyst

Answer 25

- stool exam to visualize falling leaf motility of trophozoites, iodine prep for cysts - stool antigen test - treated w/ metronidazole

Answer 26

- symptoms are the same: greasy floating stool, flatulence, malabsorption, lactose intolerance - chronic lasts more than a month, acute lasts less than a month

Answer 27

- in most mammals, especially cows - transmitted by ingestion of oocysts - risk in poorly treated water, childcare, camps, most common parasite in poorly treated water

Answer 28

- acid-fast stain: light pink round cysts in stool - can use ELISA and IF for antigen detection - treat w/ fluid and salt replacement

Answer 29

- infected humans - spread sexually

Answer 30

- genital exam, wet mount of motile organism. can do antigen test - treat w/ metronidazole

Answer 31

- mild to severe vaginitis - yellow-green discharge w/ bubbles - shift in flora towards anaerobes - strawberry cervix

Answer 32

- in infected humans - transmitted by mosquito vector

Answer 33

infected RBCs release substances that stimulate TNFa and IL-1 release

Answer 34

- blood smear - thick smear lyses cells, so extracellular parasite is visible; thin smear maintains cells, can see intracellular parasite - hematological changes: anemia, thrombocytopenia - treat w/ chloroquine - prevention w/ prophylaxis for travelers

Answer 35

- symptoms every other day - chills, fever, sweating, jaundice, headache, bone ache

Answer 36

- many animals. cats are definitive host - transmitted orally, transplacentally - immunocompromised and fetuses at greater risk

Answer 37

- serology - pyrimethamine w/ sulfadiazine or clindamycin

Answer 38

prenatal: 70% seem fine initially, but later have late visual and mental issues (chorioretinitis) adults: flu-like immunocompromised: disseminated, cysts in visceral organs, eyes, CNS

Answer 39

- in several mammals - sand fly vector - more common in south america, middle east

Answer 40

promastigote form replicates in sand fly gut amastigote form is non-motile, replicates in macrophages

Answer 41

- stained biopsy sample from human host shows amastigotes. can use PCR, serology - local treatment: pentavalent treatments intralesionally - systemic treatment: miltefosine for new world species. pentavalent treatment or amphotericin

Answer 42

- centrifugally growing - papular, central crusting - heal spontaneously, leaving scar

Answer 43

- presents the same as cutaneous, but does not heal - causes severe disfiguration

Answer 44

- in small intestine of host (children) - transmission is fecal-oral

Answer 45

- ID by kato-katz smear egg detection - treated w/ oral albendazole

Answer 46

- chronic intestinal: usually asymptomatic, or has mild abdominal distension and pain - migratory: IgE production, eosinophilia, nausea, vomiting, obstruction

Answer 47

- eggs in human stool survive in contaminated water, soil - necator is found in americas, africa, southeast asia - ancylostoma is found in africa, india, china

Answer 48

- ID by eggs in fresh stool, larvae in old stool - treat w/ oral albendazole

Answer 49

- found in infected humans - transmission is fecal-oral - most common helminth infection in US

Answer 50

- microscopy of sample obtained early in morning before defecation, by tape on perianal region - treated w/ albendazole

Answer 51

- in infected humans - larvae from feces enter soil, develop into filariform larvae, which enter skin and replicate (autoinfection) - tropical disease

Answer 52

- usually symptoms w/ eosinophilia, tropical exposure, larvae in stool - treat w/ oral ivermectin

Answer 53

- abdominal pain like that of peptic ulcer, diarrhea, vomiting - itching, red blotches on skin - vermicious pneumonia when lungs are infiltrated

Answer 54

- infected humans - transmission is fecal-oral - more likely in children in poverty

Answer 55

- microscopy to visualize tapered ends, terminal plugs of ova - albendazole

Answer 56

- heavy infections cause abdominal pain, diarrhea - can lead to IBD, colitis

Answer 57

- in striated muscle of carnivores, omnivores - transmitted by eating undercooked meat

Answer 58

- 3rd stage larvae develop into adult worms in intestines - female worms lay stage 1 larvae: initiates systemic infection by penetrating gut wall - travels through lymph, blood - enter striated muscle and encyst

Answer 59

- triad of periorbital edema, myalgia, eosinophilia - elevated muscle enzymes - definitive = cysts in striated muscle - treat w/ albendazole and steroids

Answer 60

- enteral: watery diarrhea that can last for weeks - systemic: weakness, myalgia, facial/periorbital edema, urticarial rash