CONICET | Buscador de Institutos y Recursos Humanos

A study of Trypanosoma cruzi seroprevalence was carried out in the historically endemic departments located to the north, northwest and west of Córdoba province (Argentina), south of the Gran Chaco region. Using a cross sectional design, a total of 5240 blood samples of people between 6 months and 40 years of age, living in rural communities were analyzed to detect T cruzi infection using ELISA tests and confirmed with indirect immunofluoresecence and indirect haemoagglutination. Overall seroprevalence was 5.4%, 7.9% and 7.5% in the north, northwest and west studied areas (average for all areas 6.95%). Seroprevalence increased with population age, but at a different rate in different areas. Communities of the north and west areas showed seroprevalence for T cruzi in children below 15 years of age of 0.7% and 0.4%, whereas children of the same age in the northwest region showed a seroprevalence of 2.9%. During the period 1997-2007, vector control activities showed low coverage and were heterogeneous among studied areas in terms of coverage and house visiting frequency. Average number of visits per house during the 11-year period was 1.5 and average number of visits per locality was 2.3. Vector control activities and land use changes during the last decades are the most likely causes of the overall reduction of T. cruzi prevalence in the human populations of the rural communities of the studied areas. Results of this study suggest that the vectorial transmission of T cruzi has been strongly reduced and probably interrupted in the north and west studied areas, but it is still active in the northwest area of the rural settlements of the Córdoba province.Trypanosoma cruzi seroprevalence was carried out in the historically endemic departments located to the north, northwest and west of Córdoba province (Argentina), south of the Gran Chaco region. Using a cross sectional design, a total of 5240 blood samples of people between 6 months and 40 years of age, living in rural communities were analyzed to detect T cruzi infection using ELISA tests and confirmed with indirect immunofluoresecence and indirect haemoagglutination. Overall seroprevalence was 5.4%, 7.9% and 7.5% in the north, northwest and west studied areas (average for all areas 6.95%). Seroprevalence increased with population age, but at a different rate in different areas. Communities of the north and west areas showed seroprevalence for T cruzi in children below 15 years of age of 0.7% and 0.4%, whereas children of the same age in the northwest region showed a seroprevalence of 2.9%. During the period 1997-2007, vector control activities showed low coverage and were heterogeneous among studied areas in terms of coverage and house visiting frequency. Average number of visits per house during the 11-year period was 1.5 and average number of visits per locality was 2.3. Vector control activities and land use changes during the last decades are the most likely causes of the overall reduction of T. cruzi prevalence in the human populations of the rural communities of the studied areas. Results of this study suggest that the vectorial transmission of T cruzi has been strongly reduced and probably interrupted in the north and west studied areas, but it is still active in the northwest area of the rural settlements of the Córdoba province.