Haemoflagellates (trypanosomiasis, leishmaniasis) Flashcards
Describe the disease, vector and organism involved in the 3 main haemoflagellate associated diseases
- Chagas’s disease, vector - reduvid bug (triatomine), organism - Trypanosoma cruzi
- Human African trypanosomiasis AKA Sleeping Sickness, vector - tsetse fly, organism - Trypanosoma brucei
- Leishmaniasis, vector - sandfly, organism - leishmania spp.
Which vector and organism is responsible for causing Human African Trypanosomiasis (HAT) AKA Sleeping Sickness
Vector - tsetse fly
Organism - T.brucei
Which vector and organism is responsible for causing American trypanosomiasis ie. Chaga’s Disease
Vector - reduviid bug
Organism - T.cruzi
What vector is responsible for causing Leishmaniasis
Sandfly
What are the hotspots for visceral leishmaniasis
Bangladesh, Brazil, India, Nepal and Sudan
What are the hot spots for mucocutaneous leishmaniasis
Bolivia, Brazil, Peru
What are the hot spots for cutaneous leishmaniasis
Afghanistan, Brazil, Peru, Saudi Arabia, Syria
What type of leishmaniasis does this gentleman have and what is the prognosis/treatment?
Mucocutaneous leishmaniasis.
Begins with a skin ulcer that heals but after months/years, chronic ulcers appear on skin, mouth and nose leading to tissue destruction. Can be fatal if left untreated.
Treatment -
What type of leishmaniasis is this
Diffuse cutaneous leishmaniasis
What is the main foci of visceral leishmaniasis
Bihar, India
Which form of leishmania is injected into bloodstream by macrophages
Promastigote.
Transforms into amastigotes once phagocytised by macrophages, where they multiply and are taken up by the sandfly again. Then transform into promastigotes in midgut of sandfly.
Describe prevention methods for leishmaniasis
No vaccine.
Personal precautions:
- Avoid sandflies
- Keep skin covered
- Use insect repellent
- Use impregnated clothing + bed nets
Control measures:
- Survey + control vector population
- Survey + control reservoir host populations
Medical intervention:
- Inoculation against CL tried in some countries
- Early recognition (briefings + warning cards)
Early appropriate referral to a specialist
Which country do you have both t.b. gambiense and t.b.rhodesiense
Uganda
Which leishmaniasis species causes post kalazar dermal leishmaniasis
L.donovani which also causes visceral leishmaniasis
Explain the mx of gHAT
If no clinical evidence of severe gHAT and older than 6yrs/20kg, then do LP and if <100 WBC then give PO fexinidazole.
If clinically severe gHAT then do LP, if LP shows WBC <100 then adults still get fexinidazole as bove, children get penatmidine unless WBC 6-99 in which case you get NECT.
If clinically severe gHAT and LP not done or >100 then give NECT.
Explain the mx of rHAT
- If <6 yrs and >20kg, then give fexinidazole.
- If <5 WBC on LP then give suramin (unless area where onchocerciasis b/c kills microfilariae)
- If >5 WBC on LP then give melarsoprol
Prevention and elmination of gHAT and rHAT
- gHAT
○ Case detection and treatment
○ Passive surveillance
○ Spot surveillance
○ Regular surveillance
○ Vector control- rhAT
○ Case detection + rx
○ Passive surveillance
○ Vector control
NO VACCINE for either
- rhAT
What are the clinical features of Chagas disease
Acute phase: Can be asx or symptomatic with mild illness with local swelling, LAD, redness, Romana’s/Chagoma’s. Fever, malaise, hepatosplenomegaly.
Chronic indeterminate phase (latent or asx): entered 8-10 weeks following acute phase. Lifelong seropositivity for Chaga’s, asx, no clinical disease, normal life expectancy.
Chronic phase (symptomatic) cardiomyopathy or megaviscera or both.
Describe the management options for leishmaniasis (ML/MCL/CL/VL)
One of:
- IV/IM Pentavelent antimony (sodium stibogluconate/meglumine antimoniate) for 10-20 days (20-28 days for VL)
- IV liposomal amphotericin B 10-21 days
- PO miltefosine for 28 days
- Reconstructive surgery if required forML/MCL
