Parasitology Flashcards
What are the two subspecies of Tymp brusei?
- Tymp Gambiense (W. Africa)- less severe, longer lasting (CNS involvement after a few years, death around 3 yrs) 2. Tymp Rhodisense (E. Africa)- acute (CNS involvement after a few weeks, death in months)
Describe the sx of the different stages associated with ASS.
Stage 1:
chancre at site of bite, fever, HA, swollen LNS, muscle joints, rash itchiness
Stage 2:
CNS inovlement
Neuro Sx: somnolence, altered gait, tremors, personality changes, altered consciousness (abnormal GCS)
What causes the neuro sx?
Tymps gain access to CSF at blood/CSF barrier
choroid plexus, trigeminal and dorsal root ganglia, circum ventricular organs
How do you diagnose ASS?
Find bugs in blood
Find bugs in CSF (advanced)
What drugs are used early to treat ASS before CNS involvement?
- Pentamide (IM)- DNA minor groove binder –> hypotensich, tachycardia, vomiting, hypoglycemia
- Suranim (IV slow)- Accumulateds in tymp–> LOC, Neuropathy, nephrotoxic
- Nitrofurtimox and benzidazole (Oral)- inhibits NADPH DH leading to oxidative stress and impaired mitochondrial membrane potential–> very toxic, myalgia, weakness
What are the 3 drugs used for stage 2 ASS?
- Arsenicals (IV)- ONLY for rhodisense that has progressed to CNS, liposoluble so crosses BBB, dissolved in propylene glycol (irritates tissue)–> ENCEPHALOPATHY (50% die, also hi tx failure)
- Eflorinthine (14 day IV)- Can cross CNS, but heavily secreted in urine, need a funcitonal IS, inhibits ODC, targets tymps in CNS
- Eflorithine + Nifurtimiox- BEST for late stage, targets tymps in CNS AND blood stream
What are the pathogens related to tympanosoma brucei?
1. Trypanosoma cruzi: Mexico, Kissing Bug
Chagas DIsease- mild asymptomatic, chronic–> myocarditits, megasophagus, megacolon
2. Leishmania- all over, sand fly
DRUGS: Organic antimonials interfere w/ glycolysis and FA beta oxidation, antimonial resistant use liposomal amphotericin B and miltefosine
