Print version ISSN 0036-4665
Rev. Inst. Med. trop. S. Paulo vol.43 no.5 São Paulo Sept./Oct. 2001
SUMMARY OF THESIS*
|CARVALHO, Maria Esther de - Sorologia da infecção chagásica no Programa de Controle do Estado de São Paulo, Brasil. São Paulo, 2000. [Tese de doutorado Faculdade de Saúde Pública da Universidade de São Paulo].|
SEROEPIDEMIOLOGY OF CHAGAS DISEASE IN THE CHAGAS DISEASE CONTROL PROGRAM OF THE SÃO PAULO STATE, BRAZIL
OBJECTIVE: To retrieve first-hand data concerning Chagas disease serology related to the Chagas Disease Control Program (PCDCh) from 1972 to 1997, to evaluate spatial and age group distribution of infected populations under different risk situations and to indicate how to proceed with this investigation.
METHODS: Seroepidemiological analysis of the results of indirect immunofluorescence tests applied to the surveillance of school-children and residents of domiciliary units infested with vectors parasitized by Trypanosoma cruzi or human blood having been identified in their ingesta. Probit analysis was used to investigate association of age with serological response in a sedentary population under persistent risk.
RESULTS: A positive association of age with serological response was found. A survey involving school-children showed a tendency towards a decrease in positivity between 1973 and 1983, chiefly in the Sorocaba Region, the last stronghold of Triatoma infestans in São Paulo. Titer patterns typical of low endemicity regions were found. Comparing the Campinas and Sorocaba regions, transmission was interrupted in Campinas 15 years previously. Cases of imported and orally transmitted infections produced a pattern of low but constant transmission in "transmission-free" areas. In the plateau areas most cases were autochtonous or acquired long ago. No association was found of the presence of infected vectors with seropositive residents during 1984-1997.
CONCLUSIONS: As a consequence of reduced domiciliary vector foci, low predictive values of serological tests are expected. From now on the use of serology is indicated to assess congenital cases connected to seropositive women; allochthonous populations from endemic regions and those from regions where sylvatic transmission of T. cruzi occurs.
*This thesis is available at the Library of the Instituto de Medicina Tropical de São Paulo