African trypanosomiasis

Pathogen, epidemiology, transmission

  • Tsetse fly

  • Trypanosoma brucei gambiense (West/central Africa, majority of cases, more chronic) - anthroponotic

  • Trypanosoma brucei rhodesiense (East/Southern Africa, minority of cases, more acute); animal reservoir (zoonotic)

  • Only Uganda has both gambiense and rhodesiense

Clinical

  • Chancre (primary stage), acute haemolytic stage, chronic meningoencephalitic phase

Rhodiense

  • Chancre (2-14 days)

  • 1. Hemolymphatic stage (days-weeks): fever, malaise, anemia, macular rash, lymphadenopathy, myopericarditis

  • 2. Meningoencephalitic stage (weeks): sleep disturbances, tremor, ataxia, somnolence, coma, death

Gambiense

  • Hemolymphatic stage (weeks-months-years): relapsing fever, lymphadenopathy, hepatosplenomegaly, pruritus, edema

  • Meningoencephalitic stage (months/years): insomnia, sleep disturbances, personality changes, tremor, ataxia, motor weakness, somnolence, coma, death

Diagnosis

General

  • Can see abnormal LFTs and pancytopenia (bone marrow)

Parasitological/microscopic

  • trypanosomes (blood, lymph node, CSF (stage 2)

Antibody detection

  • Antibodies to trypanosoma brucei gambiense in blood/serum/plasma (HAT sero K-Set)

  • Card agglutination test (CATT), for population screening

Nucleic acid detection

  • PCR or LAMP

  • Lumbar puncture; centrifuge CSF (WBC, Morula cells?, microscopy for trypanosomes)

Treatment

Gambiense

  • Fexinidazole (won't need to do LPs), PO for 14 days (cure rate

  • Stage 1: Pentamidine

  • Stage 2: Nifurtimox-efloornithine (NECT)

Rhodiense

Bailey slides below: