DIFFERENT BEHAVIOR OF 2 TRYPANOSOMA-CRUZI MAJOR CLONES - TRANSMISSIONAND CIRCULATION IN YOUNG BOLIVIAN PATIENTS

Different behavior of two Trypanosoma cruzi major clones: Transmission and circulation in young Bolivian patients. Experimental Parasitology 89, 285-295. Specificity of two widespread Trypanosoma cruzi clonal g enotypes or ''clonets'' (20 and 39) was first analyzed by hybridizatio n with a large set of T. cruzi stocks characterized by multigenic stud y relying on both MLEE and RAPD. Then, these clonets were detected in the blood of Chagasic children from a Bolivian endemic area by a combi nation of polymerase chain reaction and clonet-specific DNA hybridizat ion. The distribution of these clonets in patients was significantly d ifferent from that observed in the vectors of the same area (Triatoma infestans). In vectors, clonets 20 and 39 are found with comparable fr equencies (0.69 and 0.67, respectively) in contrast with patients, in whom clonet 20 and mixed infections exhibit low frequencies. The Chaga sic population can be divided into acute infections and latent infecti ons above the accepted criterion of parasitemia (direct microscopic ex amination). The results suggest a limited selection in the transmissio n of the two clonets and a further drastic control of clonet 20 parasi temia by the immune system of children patients. (C) 1998 Academic Pre ss.