Infections - Protozoa Flashcards
Leishmanisis most common presentation ?
Papule at the site of inoculation that classically evolves into an ulcer
Old world leishmanisis includes L major, L Tropica and less commonly L infantum and L aethiopica
True
New world leishmaniasis comprises L Mexicans, Lbraziliensis
True
Protozoa only cause significant morbidity in immunocompromised individuals
False - immunocompetent can also suffer high morbidity eg. Balamuthia spp
In the sandfly gut, leishmaniasis multiplies as intracellular flagellated promastigotes
False - become intracellular once engulfed by histiocytes and become amastigotes
List diseases with parasitised macrophages
His GiRL Penelope Histoplasmosis Granuloma inguinale Rhino sclerema Leishmaniasis Penicillosis
What are the clinical forms of old world leishmanisis
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)
Mucocutaneous leishmaniasis is due to Old World Protozoa
False - new world (Braziliensis, panamensis, guyanensis)
Mucocutaneous leishmaniasis can result in saddle nose deformity
True
Visceral leishmanisis is often caused by L Chigasi and infantum in adults and L Donovani in children
False - vice versa
Skin findings of post kala AZAr dermal leishmaniasis
Pigmented macules
Malar erythema
Skin coloured nodules
Verrucous papules
Co infection with HIV and leishmanisis can alter progression and presentation of leishmaniasis
True
Chronic immune activation from leishmania can accelerate AIDs and incr HIV load
True
Histo of leishmaniasis
- 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
Leishmanisis stains
Giemsa
Wright
CD1a
What is Montenegro skin test
- Phenolated suspension of killed promastigotes injected intradermal usually on volar arm
- Positive test if papule >5mm develops at site of inoculation in 46-72h
- 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
- Test cannot distinguish between past and present infection. Thus helpful in non endemic areas
Which media is required for tissue culture of leishmanisis
Nicole-Novi-McNeal or chick embryo media.
Cultures positive in 40% only
First line tx of leishmaniasis
Parenteral pentavalent antimonials and MILTEFOSINE are first line tx for cutaneous and mucocutaneous/mucosal leishmaniasis
- liposomal amphotericin B is treatment of choice for VISCERAL
Physical tx of leishmaniasis
CHAP
Cryotherapy LN2
Heat therapy
Allopurinol
PDT
Without treatment, what is the natural hx of old world leishmaniasis
L major resolves within 2-4mo
L tropica takes 6-15 mo
L tropica resolves faster than L major
False, other way around (Tropica ~one year vs. Major ~3 months)
What is Loeffler syndrome
Rare pulmonary infiltrate and peripheral eosinphilia occurring with cutaneous larva migrans (hookworm)
