Hemoflagellates (PDF)

TOPIC VIII: HEMOFLAGELLATES INTRODUCTION Amastigote It is important to note that members of Promastigote the clinically significant group of hemoflagellates...

TOPIC VIII: HEMOFLAGELLATES INTRODUCTION Amastigote It is important to note that members of Promastigote the clinically significant group of hemoflagellates Epimastigote belong to the genera Leishmania and Trypomastigote Trypanosoma. All hemoflagellates are transmitted via ARTHROPOD BITE. There are four (morphologic forms) of hemoflagellates, AMASTIGOTE TRYPOMASTIGOTE namely: Diagnostic form of Diagnostic form Leishmania Trypanosoma except T. cruzi GENERAL MORPHOLOGY FORM SIZE APPEARANCE NUCLEUS OTHER FEATURES 5 by 3 um Round to oval One, usually off Kinetoplast, with a dotlike blepharoplast Amastigote emerging from a small axoneme center 9 to 15 um long Long and slender One, located Kinetoplast, located in anterior end Promastigote in or near center Flagellum, extending anteriorly Epimastigote 9 to 15 um long Long and slightly One, located Kinetoplast, located anterior to the wider than posteriorly nucleus promastigote Flagellum, extending anteriorly Undulating membrane, extending half of body length 12 to 35 um C, S, or U shape One, located Kinetoplast, located in the posterior end Trypomastigote Long and slender anterior to the long 2 to 4 um Flagellum, extending anteriorly kinetoplast Undulating membrane, extending entire wide body length GENERAL LIFE CYCLE Two forms routinely found in human specimens: AMASTIGOTE and TRYPOMASTIGOTE AMASTIGOTE – primarily found in tissue and muscle, as well as CNS TRYPOMASTIGOTE – primarily reproduce and found in the blood PROMASTIGOTE – may be seen in blood if collected immediately after transmission or through culture EPIMASTIGOTE – primarily found in the arthropod vector PESANTE, BRITNEY C. 32  LEISHMANIA BRAZILIENSIS COMPLEX LIFE CYCLE CLINICAL SIGNIFICANCE LABORATORY DIAGNOSIS Mucocutaneous Leishmaniasis Biopsy of the infected ulcer (Giemsa-stained) o Large ulcers in the oral or nasal mucosa areas o Skin lesions TREATMENT Antimony compounds Sodium stibogluconate LEISHMANIA DONOVANI COMPLEX LIFE CYCLE Identical to L. braziliensis except: o L. donovani has different vector – specific sandfly species to each subspecies of L. donovani o Primarily affects the visceral tissue of humans – internal organs CLINICAL SIGNIFICANCE Visceral Leishmaniasis TREATMENT Kala-azar Liposomal amphotericin B Dum dum fever Sodium stibogluconate LABORATORY DIAGNOSIS Montenegro skin test Giemsa-stained slides of blood, bone marrow, lymph node aspirates and biopsies of infected areas PESANTE, BRITNEY C. 33  LEISHMANIA TROPICA COMPLEX LIFE CYCLE Identical to L. braziliensis except: o L. tropica vector – Phlebotomus sandly o Primarily affects the human lymphoid tissue of the skin CLINICAL SIGNIFICANCE LABORATORY DIAGNOSIS Old World Cutaneous Leishmaniasis Giemsa-stained slides of fluid aspirates Cutaneous leishmaniasis underneath the ulcers Oriental sore Baghdad boils TREATMENT Delhi boils Sodium stibogluconate TRYPANOSOMA BRUCEI GAMBIENSE LIFE CYCLE CLINICAL SIGNIFICANCE TREATMENT West African Sleeping Sickness or Gambian Melarsoprol Trypanosomiasis Suramin o Winterbottom’s sign Pentamidine ▪ enlargement of cervical lymph Eflornithine nodes due to trypanosomiasis o Kerandel’s sign ▪ delayed sensation to pain o Somnolence ▪ excessive sleepiness LABORATORY DIAGNOSIS Giemsa-stained blood smears and lymph node aspirates IgM detection for T. brucei gambiense PESANTE, BRITNEY C. 34  TRYPANOSOMA BRUCEI RHODESIENSE LIFE CYCLE Identical to T. brucei gambiense except: o T. brucei rhodesiense vector is a different Tsetse fly species CLINICAL SIGNIFICANCE LABORATORY DIAGNOSIS East African Sleeping Sickness or Rhodesian Giemsa-stained blood smears Trypanosomiasis IgM detection for T. brucei rhodesiense o More virulent than Gambian Trypanosomiasis TREATMENT Identical to T. brucei gambiense TRYPANOSOMA CRUZI LIFE CYCLE LABORATORY DIAGNOSIS CLINICAL SIGNIFICANCE Giemsa-stained blood smears Chagas’ Disease or American Trypanosomiasis TREATMENT o Chagoma – erythematous nodule at the Nifurtimox site of infection o Romaña’s sign – unilateral edema of the eyelids PESANTE, BRITNEY C. 35  SUMMARY HEMOFLAGELLATE VECTOR CLINICAL NOTES TO SIGNIFICANCE REMEMBER Leishmania braziliensis Lutzomyia Mucocutaneous sandfly leishmaniasis Psychodopygus Chiclero ulcer sandfly Espundia Forest yaws Pian bois Uta Leishmania donovani Lutzomyia Visceral Montenegro sandfly leishmaniasis skin test Phlebotomus Kala-azar sandfly Dum dum fever Leishmania tropica Phlebotomus Old world cutaneous sandfly leishmaniasis Dry or urban cutaneous leishmaniasis Oriental sores Bahgdad boils Delhi boils Trypanosoma brucei Glossina palpalis West African Winterbottom’s gambiense Glossina sleeping sickness sign tachinoides Gambian Kerandel’s sign trypanosomiasis Somnolence Trypanosoma brucei Glossina East African More virulent rhodesiense morsitans sleeping sickness than T. brucei Glossina Rhodesian gambiense pallidipes trypanosomiasis Trypanosoma cruzi Reduviid bug Chagas’ disease Chagoma Kissing bug American Romaña’s sign Conenose bug trypanosomiasis Triatomid bug PESANTE, BRITNEY C. 36