MOLECULAR DIAGNOSIS AND TYPING OF T. CRUZI IN DIFFERENT EPIDEMIOLOGICAL AND CLINICAL SCENARIOS

BURGOS JM; BISIO M; ALTCHEH J; MARCET P; SEIDENSTEIN M; BEGHER S; VIGLIANO C; LEVITUS G; PERRONE SV; GURTLER R; MACCHI L; FREILIJ H; LEVIN MJ; SCHIJMAN A

San Carlos de Bariloche

Congreso; XXXIX Anual meeting de la Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular (SAIB); 2003

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

Infection by T. cruzi was diagnosed, monitored and characterized by PCR-based techniques in different settings; I) congenital transmission, II) etiological treatment outcome, III) parasitic reactivation due to immunosupression IV) re-emergence of infection in domestic and peridomiciliary vectors of an endemic area under surveillance. Molecular typing was done by lineage-specific PCR, cross-hybridization of minicircle amplicons with radiolabeled probes, LSSP-PCR, RFLP-PCR and sequencing. Results: I) We observed a major incidence of congenital transmission from mothers with positive PCR results during pregnancy (p<0.05). The parasitic molecular profiles were similar within each pair of mother-newborn and different among patients from different endemic areas. II) 16 infants, 24 children and 60 chronically infected adults were followed-up after benznidazol treatment; 0% infants, 12.5% children but 40% adults remained persistently or intermittently PCR positive after 3 years post-treatment (p<0.05). III) An AIDS patient with presumptive toxoplasma-driven encephalitis presented T. cruzi PCR positivity in brain biopsy, improving his NMR following benznidazol treatment. The reactivation of two chagasic patients who received orthotopic heart transplantation was detected by blood-based PCR 30-42 days earlier than by routine monitoring. IV) PCR analysis of faeces from T. infestans collected in domestic and peridomestic sites from Amamá showed infection by T.cruzi group II strains.