Infections - Protozoa

Question 1

Leishmanisis most common presentation ?

Answer 1

Papule at the site of inoculation that classically evolves into an ulcer

Question 2

Old world leishmanisis includes L major, L Tropica and less commonly L infantum and L aethiopica

Answer 2

True

Question 3

New world leishmaniasis comprises L Mexicans, Lbraziliensis

Answer 3

True

Question 4

Protozoa only cause significant morbidity in immunocompromised individuals

Answer 4

False - immunocompetent can also suffer high morbidity eg. Balamuthia spp

Question 5

In the sandfly gut, leishmaniasis multiplies as intracellular flagellated promastigotes

Answer 5

False - become intracellular once engulfed by histiocytes and become amastigotes

Question 6

List diseases with parasitised macrophages

Answer 6

His GiRL Penelope
Histoplasmosis
Granuloma inguinale
Rhino sclerema
Leishmaniasis
Penicillosis

Question 7

What are the clinical forms of old world leishmanisis

Answer 7

Zoonotic (L major) - usually mild rapid course
Anthroponotic (L tropica) - more chronic course
Recidivans 0 chronic destructive form
Lupoid - clinical and histological resemblance to lupus vulgaris TB (epithelioid granuloma surrounded by histiocytes)

Question 8

Mucocutaneous leishmaniasis is due to Old World Protozoa

Answer 8

False - new world (Braziliensis, panamensis, guyanensis)

Question 9

Mucocutaneous leishmaniasis can result in saddle nose deformity

Answer 9

True

Question 10

Visceral leishmanisis is often caused by L Chigasi and infantum in adults and L Donovani in children

Answer 10

False - vice versa

Question 11

Skin findings of post kala AZAr dermal leishmaniasis

Answer 11

Pigmented macules
Malar erythema
Skin coloured nodules
Verrucous papules

Question 12

Co infection with HIV and leishmanisis can alter progression and presentation of leishmaniasis

Answer 12

True

Question 13

Chronic immune activation from leishmania can accelerate AIDs and incr HIV load

Answer 13

True

Question 14

Histo of leishmaniasis

Answer 14

• ulceration, pseudoepitheliomatous hyperplasia
• mixed inflammatory infiltrate with histiocytes, lymphocytes plasma cells and neutrophils
• amastigotes present within dermal macrophages - especially those within the papillary dermis - evident in 50% of skin biopsies
• over time, lesions develop more giant cells and fewer parasites
• in longstanding lesions, tuberculoid granulomas can be seen

Question 15

Leishmanisis stains

Answer 15

Giemsa
Wright
CD1a

Question 16

What is Montenegro skin test

Answer 16

1. Phenolated suspension of killed promastigotes injected intradermal usually on volar arm
2. Positive test if papule >5mm develops at site of inoculation in 46-72h
3. Positive in up to 90% of pt with cucutaneous and mucocutaneous leishmaniasis of over 3 months and negative in pt with diffuse cutaneous ANERGIC leishmaniasis
4. Test cannot distinguish between past and present infection. Thus helpful in non endemic areas

Question 17

Which media is required for tissue culture of leishmanisis

Answer 17

Nicole-Novi-McNeal or chick embryo media.

Cultures positive in 40% only

Question 18

First line tx of leishmaniasis

Answer 18

Parenteral pentavalent antimonials and MILTEFOSINE are first line tx for cutaneous and mucocutaneous/mucosal leishmaniasis
- liposomal amphotericin B is treatment of choice for VISCERAL

Question 19

Physical tx of leishmaniasis

Answer 19

CHAP

Cryotherapy LN2
Heat therapy
Allopurinol
PDT

Question 20

Without treatment, what is the natural hx of old world leishmaniasis

Answer 20

L major resolves within 2-4mo

L tropica takes 6-15 mo

Question 21

L tropica resolves faster than L major

Answer 21

False, other way around (Tropica ~one year vs. Major ~3 months)

Question 22

What is Loeffler syndrome

Answer 22

Rare pulmonary infiltrate and peripheral eosinphilia occurring with cutaneous larva migrans (hookworm)