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Flashcards in protozoa infections Deck (25)
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1
Q

Humans can become infected by toxo by any of several routes:

4

A
  1. Eating undercooked meat of animals harboring tissue cysts
  2. Consuming food or water contaminated with cat feces
  3. Blood transfusion, organ transplantation, needlestick
  4. Transplacentally from mother to fetus (aka congenital toxo)
2
Q

________ localize to neural or muscular tissue

A

Tachyzoites

3
Q

oocysts

A

capsule

4
Q

congenital tox

A

1st and 3rd trimester. with those from the 1st more CNS related effects

5
Q

primary infection for toxo is

A

a positive IgM

6
Q

Reactivation: Cannot use presence or absence of IgM to diagnose reactivation

A

yep

7
Q

tx with toxo:

primary vs reactivation

A
Primary Infection
Usually self-limited, no treatment needed
If eye involvement, treat with 
Pyremethamine + sulfadiazine  OR
Pyremethamine + clindamycin  
 AND
Leucovorin (folinic acid)

Reactivation: the same as primary with eye involvement, but with higher doses

8
Q

prevention of toxo in HIV

A

need to be on trimethoprim sulfamethoxazole (Bactrim) until CD4 count > 100

9
Q

Protozoa that are flagellates

Transmitted by bite of the sandfly which usually bites at night

A

leishmaniasis

10
Q

three forms of leishmaniasis

A
  1. cutaneous
  2. mucocutaneous
  3. visceral (kalazar)
11
Q

leishmaniasis:
Lesions can be single or multiple; appear 6 weeks after inoculation, starts as a papule, ulcerates over time
Classic appearance: “heaped up” borders, non-tender; on exposed skin
May heal spontaneously (90% of cases)

A

Cutaneous:

12
Q

leishmaniasis :

Initial symptoms similar to cutaneous and resolve
Months to years later, 1-5% of patients develop ulcers on oral or nasal mucousa
Progression of the infection is slow, but unless treatment is given, the entire nasal mucosa and the hard and soft palates can be destroyed.
Death usually occurs from secondary infection

A

Mucocutaneous (Only New World)

13
Q

leishmaniasis :

Amastigotes enter macrophages; disseminate to liver, spleen, and bone marrow
Mostly seen in children and immunosupressed adults from Bangladesh, India, Sudan and Brazil
Onset can be insidious or acute; weeks to months after initial infection
Symptoms: Fever, weight loss, cachexia, diarrhea, malabsorption
Physical Exam: Organomegaly; Earth gray skin color, nodular skin lesions, oral and nasal ulcers
Labs: Pancytopenia, Hypergammaglobulinemia

A

visceral

14
Q
Cellular immune responses (Th1) are \_\_\_\_\_\_\_\_
Humoral responses(Th2) \_\_\_\_\_\_\_\_\_\_\_

AIDS patients and
Immunocompromised hosts

A

Cellular immune responses (Th1) are protective
Humoral responses(Th2) protective
AIDS patients frequently develop severe Leishmania infections
Immunocompromised hosts tend to relapse

15
Q

diagnosis of cutaneous form of leishmans

A

Smear, scrape or touch prep of skin lesion stained with giemsa

16
Q

diagnosis of visceral form of leishman

A

Definitive diagnosis based on demonstration of amastigotes in tissue

17
Q

leishmaniasis tx

A

all can use miltefosine and azoles

18
Q

liver abscess

A

Entamoeba histolytica

19
Q

tx. for Entamoeba histolytica

A

metronidazole

20
Q

Hiker’s/backpacker’s diarrhea due to ingestion of water from mountain streams contaminated by animals

A

giardia lamblia

21
Q

Microscopy of stool shows trophozoites and cysts

A

giardia

22
Q

how to tx. with giarda

A

metronidazole

23
Q

CRYPTOSPORIDIUM is a

A

protozoa

24
Q

CRYPTOCOCCUS is a

A

fungus

25
Q

Cryptosporidum Treatment

A

self-limited but can also take nitazoxidine