Trypanosomiasis Ziad Elnasser, MD, Ph.D

Parasitology Trypanosoma brucei with 3 subspecies: Trypanosoma brucei with 3 subspecies: gambiense, rhodesiense and brucei identified by their biology, zymodemes and DNA types. gambiense, rhodesiense and brucei identified by their biology, zymodemes and DNA types. Life cycle: Glossina fly (tse tse), epimastigote form, trypomastigote form, saliva, VSG development, blood, division, morphology change, antigenic variation, glossina fly. Life cycle: Glossina fly (tse tse), epimastigote form, trypomastigote form, saliva, VSG development, blood, division, morphology change, antigenic variation, glossina fly.

African trypanosomiasis (Sleeping sickness) Lethal meningoencephalitis. Lethal meningoencephalitis. West african or east african types, Nagana in cattle. West african or east african types, Nagana in cattle. Epidemiology: Africa 10,000 – 20,000/y. Epidemiology: Africa 10,000 – 20,000/y. Humans are reservoirs in gambian while the antelop in Rhodesian. Humans are reservoirs in gambian while the antelop in Rhodesian.

pathogenesis Skin chancre. Skin chancre. Blood and LNs, IgM and C, antigenic variation. Blood and LNs, IgM and C, antigenic variation. CNS, and heart small vessles involvement Hg, demyelinating panencephalitis. CNS, and heart small vessles involvement Hg, demyelinating panencephalitis. Poly clonal B cell activation→IgM, heterophile Abs, anti DNA, and RF, cell destruction, immune complexes, anemia and vasculitis. Poly clonal B cell activation→IgM, heterophile Abs, anti DNA, and RF, cell destruction, immune complexes, anemia and vasculitis.

Clinical Aspects Chancre. Chancre. Fever, tender LNs, rash, headache, and impaired mentation. Fever, tender LNs, rash, headache, and impaired mentation. Heart failure, convulsions, coma and death may follow. Heart failure, convulsions, coma and death may follow. Attention waves, tremors, sphinctor control is lost, seizures, transient bouts of paralysis, and final coma. Attention waves, tremors, sphinctor control is lost, seizures, transient bouts of paralysis, and final coma.

Diagnosis Lymph nodes aspirate, Blood, CSF→ look for trypomastigotes, if not centrifuge and examine buffy coat. Lymph nodes aspirate, Blood, CSF→ look for trypomastigotes, if not centrifuge and examine buffy coat. Animal inoculation. Animal inoculation. Ab detection IgM type, simple card agglutination. Ab detection IgM type, simple card agglutination. DNA probes. DNA probes.

Treatment LP must be done first to use agents crosses the blood – brain barrier. LP must be done first to use agents crosses the blood – brain barrier. Melarsoprol B is the best. Melarsoprol B is the best. Eflornithin (ornithine dexarboxylase inhibitor) alone or with Suramine. Eflornithin (ornithine dexarboxylase inhibitor) alone or with Suramine. Less toxic than Mel B, varialbly effective for T. rhodesiense. Less toxic than Mel B, varialbly effective for T. rhodesiense. Suramine, Pentamidine, or eflornithine can be used if the CNS is not involoved. Suramine, Pentamidine, or eflornithine can be used if the CNS is not involoved.

Prevention Tse tse fly control measures. Tse tse fly control measures. Insecticides. Insecticides. Deforstation. Deforstation. Sterile males. Sterile males. Eradication of reservoirs. Eradication of reservoirs. Vaccine difficulties. Vaccine difficulties. Personal protection from flies. Personal protection from flies.

American Trypanosomiasis Trypanosoma cruzi and reduvid bug. Trypanosoma cruzi and reduvid bug. No extracellular multiplication (amastigote) No extracellular multiplication (amastigote) Trypomastigote → amastigote → trypomastigote → epimastigote in bug. Trypomastigote → amastigote → trypomastigote → epimastigote in bug. Many serotypes. Many serotypes. C or U shape, large kinetoplast, narrow undulating membrane. C or U shape, large kinetoplast, narrow undulating membrane.

Chagas disease Leading cause of heart disease in s. America. Leading cause of heart disease in s. America. Reduvid bug bites at night. Reduvid bug bites at night. Kissing bug or assassin bug. Kissing bug or assassin bug. Rats, cats, dogs, opossums, and armadillos act as reservoirs. Rats, cats, dogs, opossums, and armadillos act as reservoirs. Blood transfusion and transplantation. Blood transfusion and transplantation.

Pathogenesis Local chancre or Chagoma. Local chancre or Chagoma. Febrile illness one to 3 months. Febrile illness one to 3 months. Any nucleated cell in the body can be infected, heart, CNS, skeletal muscles. Any nucleated cell in the body can be infected, heart, CNS, skeletal muscles. Penetrin on trypomastigote binds to fibronectin transforms to amastigote, pseudocyst development. Penetrin on trypomastigote binds to fibronectin transforms to amastigote, pseudocyst development. Humoral and CMI destroys the organism. Humoral and CMI destroys the organism. Parasite antigen binds to other tissues resulting more injury, heart damage. Parasite antigen binds to other tissues resulting more injury, heart damage.

Clinical Aspects Nodular erythematous chagoma. Nodular erythematous chagoma. Romana’s sign if entry is through the eye. Romana’s sign if entry is through the eye. Fever, LNs ↑, hepatospleenomegally. Fever, LNs ↑, hepatospleenomegally. Meningeal irritation, tachycardia, ECG changes. Meningeal irritation, tachycardia, ECG changes. Myocardium and the induction system. Myocardium and the induction system. Mega colon and megaeosophagus. Mega colon and megaeosophagus.

Diagnosis Trypomastigote in the peripheral blood. Trypomastigote in the peripheral blood. Xenodiagnosis. Xenodiagnosis. Culture or animal inoculation. Culture or animal inoculation. Chronic disease difficult to diagnose. Chronic disease difficult to diagnose. Immunodiagnosis. Immunodiagnosis. PCR. PCR.

Treatment and prevention Nitrofuramox. Nitrofuramox. Benznidazole. Benznidazole. Allopurinol. Allopurinol. Insecticides, fumagatives. Insecticides, fumagatives. Testing blood donors. Testing blood donors. No vaccines. No vaccines.

Filarial Worms Wuchereria bancrofti Wuchereria bancrofti Brugia malayi. Brugia malayi. Loa loa Loa loa Onchocerca volvolus. Onchocerca volvolus.