Lecture 8.0 - Other blood parasites Notes Flashcards
Sleeping sickness
African trypanosomiasis
Trypanosomiasis: Trypanosomes are a group of parasitic protozoa belonging to the genus Trypanosoma. These organisms are primarily found in blood and tissue fluids of vertebrate hosts, including humans and other mammals.
The 3rd subspecies, which is an important cause of animal trypanosomiasis
T. brucei brucei,
Name the 2 subspecies that cause human African trypanosomiasis.
- West African/Gambian
trypanosomiasis: riverine forest- provides suitablle environment for viral transmission since its promote survival of tsetse flies, reservoir- HUMAN - East African/Rhodesian trypanosomiasis is a zoonosis; transmission occurs in a savannah environment. Antelopes are major reservoir.
occurs at the
site of the infected tsetse fly bite
trypanosomal chancre
Discuss the features and the 2 stages of East African/Rhodesia trypanosomiasis
- Acute; short incubation period of (1-2 weeks)
Stage 1- haemolymphatic stage:
- myocarditis
- pancytopenia
- multi-organ failure
- ARDS-Acute Respiratory Distress Syndrome
TREAT STAGE 1 WITH SURAMIN
Stage 2: if stage 1 is not treated promptly and patient has
survived:
- meningo-encephalitic stage;
Rapidly fatal if not treated
TREAT SAGE 2 WITH MELARSOPROL
Discuss the features and the 2 stages of West African/gambien trypanosomiasis
- Long incubation period: months to years
- Gradual onset of stage 1 (slow and steady development of symptoms or the progression of a condition over a period of time)
*Typical sign of haemolymphatic stage:
posterior cervical lymphadenopathy
(Winterbottom’s sign)
TREAT STG 1 WITH SURAMIN OR PENTAMIDINE
- Eventually CNS is invaded: stage 2
*Slowly progressive loss of higher brain function, can take years but if untreated,
eventually unrousable coma and death
TREAT STAGE 2 WITH MELASOPROL OR EFLORNITHINE
Manifestations of terminal sleeping sickness
- coma,
- dehydration,
- pneumonia,
- malnutrition,
- bedsores,
- sepsis…..death
Done when checking for trypanosomes in the CSF
that indicate CNS involvement
Lumbar puncture
New drug for treatment of both West and East African trypanasomiasis
Fexinidazole – oral, non-toxic, effective in both types of
disease, all stages
what is the treatment for east african trypnosomiasis (T.B. rhodesiense)
Stage 1 (haemolymphatic): suramin
* Stage 2 (meningoencephalitic): melarsoprol
what is the treatment for west african trypanosomiasis?
West African trypanosomiasis (T. b. gambiense):
* Stage 1: suramin or pentamidine
* Stage 2: melarsoprol or eflornithine (+/- nifurtimox
Drug toxicity following melarsoprol administration
- fatal encephalopathy
- exfoliative dermatitis
Trypanasomiasis control
- Active case detection
- Prompt case treatment
- Insecticide spraying of
breeding sites - prophylactic pentamidine
- Tsetse traps: dark blue
and black cloth attracts
tsetse flies; they are then
killed by insecticides
impregnated in cloth - Release of laboratory-bred
sterile male tsetse flies:
compete with wild males
for females and reduce
population breeding rat
Advice for travellers to risk areas for trypanosomiasis
- Wear light colours, not
dark blue or black - Use insect repellents
- Close car windows
- NB If you get ill – tell the doctor
about that tsetse bite! - Like malaria, East African
trypanosomiasis is an emergency
Filariasis
parasitic disease caused by filarial worms
