Lecture 02 - African Trypanosomes Flashcards
What are the features of trypanosomes
anteriorly located kinetoplast, centrally located nucleus, dividing body, undulating membrane and a flagellum running along the undulating membrane
What are the two subspecies trypanosomes
T. brucei rhodesiense, and T. brucei gambiense
What does trypanosomes cause
african sleeping sickness
What trypanosome infects animals only
T. brucei brucei
What are trypanosomes
a protozoan hemoflagellates
How do trypanosomes multiply
trypomastigotes that circulate in the mammalian blood steam and other extracellular spaces
What is the vector of trypanosomes
african tsetse fly
Where does trypanosomiasis sickness occur
only in sub-saharan africa
What species makes up most of the cases of trypanosomiasis sickness
T. brucei gambiense
How many counties is sleeping sickness endemic in
36
What are rare forms of transmission of Trypanosomes
transfusion, mother to child, mechanical transmission, laboratory accidents, transmission of the parasite through sexual contact
What makes the tsetse fly distinguishable
one wing rests on top of the other, long proboscis which extends forward and attached by a bulb to the bottom of the head
What kind of parasite are trypanosomes
obligate parasites
How long is the incubation period for T, brucei rhodesiense
3-21 days
What is stage one of pathogenesis of trypanosomes
the hemolymphatic stage
What is stage two of pathogenesis of trypanosomes
the CNS stage
How do trypanosomes evade the immune response
change the surface coat of the outer membrane of the trypomastigote
What is the clinical manifestation of T. brucei gambiense
cutaneous nodule or chancre, systemic chronic illness characterized by intermittent fever, posterior cervical lymphadenopathy
What is the clinical manifestation of T. brucei rhodesiense
generalized illness days to weeks after inoculation with manifestation including high fever, thrombocytopenia, hepatitis, myocarditis, cutaneous chancre, anemia
What are key characteristics of T. brucei rhodesiense
acute early CNS disease, progress rapidly, large sore at site of bite, severe symptoms, death within months
What are key characteristics of T. brucei gambiense
chronic late CNS disease, progress slowly, mild symptoms at first, death within years if not treated
What are some of the ways to diagnose T. brucei rhodensiense
blood, lymph node aspirate, chancre biopsy or aspirate, CSF
What are some of the ways to diagnose T. brucei gambiense
lymph node aspirate, blood, chancre aspirate, CSF, serology, agglutination, ELISA, IFA
What is the promastigote level of maturation
elongated body form, kinetoplast and kinetosome are at the anterior end in front of the nucleus
What is the trypomastigote level of maturation
blood stream form, had undulating membrane, kinetoplast and kinetosome at the posterior end behind the nucleus
What is the amastigotes level of maturation
short, flagella not visible
What is the epimastigotes level of maturation
nucleus and kinetoplast are close together
What are the morphological features of T. brucei
flagellum that begins as an undulating membrane originating posterior to the kinetoplast
What are the treatment options for T. brucei gambiense
Stage 1 - pentamidine and suramin
Stage 2 - eflornithine and melarprosol or Eflornithine+nifurtimox
What are the treatment options for T. brucei rhodesiense
Stage I - suramin
Stage II - Melarsoprol
Best way to prevent trypanosome infection
eradication of the vector
What is a new oral treatment for T. brucei gambiense
fexinidazole
