Molecular diagnosis and typing of T. cruzi in different epidemiological and clinical scenarios

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

San Carlos de Bariloche, Argentina

Congreso; XXXIX Anual meeting de la Sociedad Argentina de Investigaciones en Bioquimica y Biologia Molecular; 2003

Sociedad Argentina de Investigaciones en Bioquimica y Biologia Molecular (SAIB)

Infection by T. cruzi was diagnosed, monitored and characterized by PCR-based techniques in different settings; I) congenital transmission, II) etiological treatment, III) parasitic reactivation due to immunosupression IV) re-emergence of infection in domestic-peridomiciliary vectors of an endemic area under surveillance. Molecular typing was done by lineage-specific PCR, cross-hybridization of amplicons with radiolabeled probes, LSSP-PCR, RFLP-PCR and sequencing. Results: I) We observed major incidence of congenital transmission from pregnant women with positive PCR results (p<0.05). The parasitic signatures were similar within each pair of mother-newborn and different among cases of different endemic areas, II) 16 infected infants, 24 children and 60 adults were followedup after benznidazol treatment; 100% infants, 87.5% children but 60% adults remained persistently PCR negative during 3 years of post-treatment monitoring (p<0.05). III) The reactivation of two chagasic patients who received orthotopic heart transplantation was detected 30-42 days earlier by PCR than by routine monitoring. Chagasic encephalitis was diagnosed by PCR in brain biopsy of an AIDS patient with presumptive diagnosis of toxoplasmosis, who improved following benznidazol treatment. The parasitic profiles were characterized. IV) PCR analysis of faeces from T. infestans collected in domestic and peridomestic sites from Amamá showed infection by T. cruzi group II strains.