Trypanosoma cruzi (Chagas disease)

Epidemiology: 1) United States, Central & South America rarely, cases orginate in United States 2) transmitted by kissing bugs of the family Reduviidae, so named because it often bites the face 3) bug defecates at the time of biting 4) bug feces contain infective trypomastigotes that penetrate the skin as a result of scratching or rubbing or through intact mucosa 5) infection may be transmitted by blood transfusion 6) vertical transmission from mother to baby 7) dogs, rodents, armadillos, & other domestic & wild animals serve as reservoirs Pathology: 1) after gaining access to tissues, typomastigotes transform into dividing amastigotes 2) when the infected cell is full of amastigotes, transformation to trypomastigotes occurs, followed by cell rupture 3) trypomastigotes are released into the peripheral blood where they reach distant tissues & begin the replicative cycle again 4) cross-reactivity of Trypanosoma cruzi antigens with human protein(s) serology> - R1 & R3 epitopes of TCFL5, recognized by T- & B-cells, respectively Clinical manifestations: - see Chagas disease Laboratory: 1) Trypanosoma identified in isolate a) diagnosis is made by demonstration of trypomastigotes in blood, buffy coat or aspirates of lymph nodes or chagomas b) trypomastigotes - curved with S & C shapes - measure up to 20 um in length - kinetoplast larger than that of T brucei 3) Trypanosoma identified by culture 4) Trypanosoma cruzi DNA 5) Trypanosoma cruzi serology: a) EIA, IFA & ELISA are available b) false positives may occur in patients with Leishmaniasis c) antibodies against TCFL5 (nuclear antigen) 6) xenodiagnosis in endemic areas a) examination of the gut contents of laboratory-raised rejuviid bugs that have been allowed to feed on the victim 7) see ARUP consult [2] Management: - see Chagas disease

Related

arthropod-borne infection Chagas disease

Properties

KINGDOM: animal PHYLUM: protozoa