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Flashcards in Parasitology 5 Deck (49):
1

Describe the location of Leishmaniasis infection

blood and tissues

2

Which forms of Leishmaniasis cause only cutaneous infection?

L tropica
L major

3

Which forms of Leishmaniasis cause cutaneous and mucocutaneous infection?

L mexicana
L brazillensis

4

Which forms of Leishmaniasis cause visceral infection?

L chagasi
L donovani
L infantum

5

What is the vector of Leishmaniasis?

sand fly

6

Describe the lifecycle of Leishmaniasis

Vector borne- sand fly is infected when it takes a blood meal from infected host. Parasites develop in the sand fly, transmitted to a new host when fly bites again
Within humans, the leishmania is adapted to live in WBC and avoid being degraded

7

_____ and ______ are important reservoirs of Leishmaniasis

dogs and rodents

8

_______ transmission of Leishmaniasis has been documented in dogs

vertical

9

The great majority of ______ cases of Leishmaniasis occur in India, Bangladesh, Nepal, Sudan, and Brazil

visceral

10

Describe the epidemiology of Leishmaniasis

- 350 million at risk
~12 million infected
~2 million new cases/year
~60,000 deaths/year

tropical and subtropical regions

11

Describe the presentation of cutaneous Leishmaniasis

- Starts as a bump then an ulcerative sore at primary site; satellite lesions
- abundant amastigotes in lesions
- spontaneous healing with scarring

12

______ may reduce the duration of cutaneous Leishmaniasis lesions and help them heal faster

Fluconazole

13

Describe the presentation of mucocutaneous Leishmaniasis

- metastasis months to years after primary lesion heals

- ulceration nasopharynx tissues, amastogotes in lesions

14

For both mucocutaneous and visceral Leishmaniasis, ________ leads to immunity

chemotherapeutic cure

15

Describe the presentation of visceral Leishmaniasis

Onset at 2-12 months, fever and wasting with hepatosplenomegaly

16

How is Leishmaniasis diagnosed

biopsy or aspirate the lesion, stain with Giemsa, look for amastigotes.
In US, CDC does DNA tests

17

Describe treatment for cutaneous Leishmaniasis

typically self-resolves with scarring
L. major treated with fluconazole

18

Describe treatment for mucocutaneous Leishmaniasis

Antimonials- not always effective and side effects
Amphotericin B is an alternate but expensive & iv daily

19

Describe treatment for visceral Leishmaniasis

miltefosine- drug of choice, given for 4 weeks, cures 94% Amphotericin B is an alternate

20

In eastern and southern Africa, African Trypanosomiasis is caused by Trypanosoma _________

rhodesiense

21

In western and central Africa, African Trypanosomiasis is caused by Trypanosoma ________

gambiense

22

What is the vector for Human African Trypanosomiasis?

tsetse fly

23

Contrast the progression of Western vs Eastern Human African Trypanosomiasis

Western: reservoir is human, chronic (years to progresion)

Eastern: reservoir is antelope, cattle; rapid progression in 1-4 weeks

both 100% mortality without treatment

24

The African Trypanosomiasis parasite is free floating in the blood stream and undergoes __________ to avoid host immunity

antigenic variation

25

Describe the epidemiology of HAT

Exclusively sub-Saharan Africa
Re-emerging
60 million people at risk

26

How is HAT diagnosed?

direct examination of blood, lymph, and CSF (rhodesiense)

27

What is Winterbottom's sign?

Enlargement of posterior cervical lymph nodes seen in African Trypanosomiasis

28

What drugs are used to treat early stage trypanosomiasis?

Pentamidine: useful for gambiense, well tolterated

Suramin: useful for rhodesiense

29

What drugs are used to treat late stage trypanosomiasis?

Melarsoprol: discovered in 1949, used against both forms. Arsenic derivative with many side effects including fatal encephalopathy (3% to 10%).

Eflornithine: Only effective against T.b. gambiense. Less toxic but infusion every 6 hr for 14 days.

30

What organism causes Chagas disease?

Trypanosoma cruzi

31

What is the reservoir for Trypanosoma cruzi?

rats, cats, dogs, wild animals

32

What is the location of Trypanosoma cruzi?

blood, lymphatics & tissues (intracellular)

33

What is the vector of Trypanosoma cruzi?

reduviid bug

34

How is Trypanosoma cruzi transmitted?

Bite of infected reduviid bug, transfusion, transplantation, IVDU, possibly vertical

35

Contrast the epidemiology of Chagas in rural vs urban settings

rural: vector/reservoir in proximity to human dwellings

urban: contaminated blood supplies; IV drug use

36

How is spread of Chagas prevented?

Screen blood supply
good housing
vector control

37

Describe the progression of Chagas disease

Acute: 2-4 months fever, chagoma, hematogenous spread

Chronic: 10-20 years, damage to nerve, muscle, heart, esophagus, colon. Death from sudden heart attack is common

38

How is Chagas diagnosed?

acute: trypomastigotes in blood
chronic: xenodiagnosis
Recently approved strip assay

39

How is acute chagas treated?

Benznidazole or Nifurtimox

Neither FDA approved, get from CDC

40

What is the location of Trichomoniasis?

Urogenital- luminal

41

There are no ________ or ______ stages in the life cycle of Trichomoniasis

free living or encysted

42

How is Trichomonas vaginalis transmitted?

direct sexual contact, rarely non-sexual contact

43

70% of females infected with Trichomonas vaginalis are ______

asymptomatic

44

Describe signs of Trichomoniasis in women

vaginitis, burning and itching
inflammation of squamous epithelia
“frothy” vaginal discharge with unusual odor

45

Describe signs of Trichomoniasis in men

itching, irritation inside penis
burning after urination or ejaculation
mild discharge

46

List complications of Trichomoniasis

preterm delivery, LBW
increased risk of acquiring HIV

47

People who have been successfully treated for Trichomoniasis can be _______

re-infected

48

How is Trichomoniasis diagnosed?

microscopic observation of motile parasites
DNA test is available now at major centers

49

What is the treatment for Trichomoniasis?

metronidazole or tinidazole