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INTRODUCTION: Autochthonous malaria in the State of Sao Paulo is characterized by sporadic outbreaks in the western region and by persistent transmission in the eastern region, where oligosymptomatic cases with low parasitemia due to Plasmodium vivax occur. The objectives of this study were to assess the completeness of autochthonous malaria notification forms; to estimate the incidence trends of autochthonous cases in the State of Sao Paulo from 1980 to 2007; and to analyze the clinical and epidemiological patterns of cases in two autochthonous regions over this period. METHODS: This was a descriptive study that analyzed 18 variables on the notification form for malaria in the State of Sao Paulo, comparing these two regions over two periods (1980-1993 and 1994-2007). The data sources were SUCEN/SES/SP, SINAN/CVE/SES/SP and DATASUS. RESULTS: The completeness was greater than 85% for 11 variables. The incidence trend was decreasing. There were 821 autochthonous cases: 91.6% occurred in the eastern region, predominantly due to Plasmodium vivax. Asymptomatic infection had a higher percentage in the second period (p < 0.001). CONCLUSIONS: The completeness of the information was satisfactory. The clinical differences observed deserve attention from epidemiological surveillance agencies, which need to deal with the challenge of asymptomatic infection by Plasmodium.

O presente trabalho teve como objetivo estabelecer critérios adequados à triagem de doadores de sangue de regiões com características epidemiológicas distintas, para malária. Foram estudados 3 locais com critérios de seleção diferentes: São Paulo, SP (sem transmissão vetorial), Belém (baixa transmissão ativa), Matupá, Belém, PA e Peixoto de Azevedo, MT (alta transmissão ativa). A pesquisa de plasmódios foi realizada por gota espessa, QBC Test® e imunofluorescência para pesquisa de antígenos, tendo sido todas as amostras negativas. Houve grande variação na positividade para anticorpos antiplasmodiais por IFI-IgG anti P. vivax e P. falciparum entre doadores aptos nos 3 locais de estudo e entre doadores aptos e inaptos em São Paulo (aptos 1,98%, inaptos 22,3%, p < 0.01) e Belém (aptos 17,2%, inaptos 58,3%, p < 0.01), o que atesta a validade da triagem clínico-epidemiológica realizada. Em Matupá e Peixoto de Azevedo não houve doadores inaptos e a positividade foi de 80,6%. Consideramos que em bancos de sangue a triagem deve seguir critérios clínico-epidemiológicos adequados à situação de cada região. Os métodos laboratoriais de triagem, devem ser para detecção de plasmódios (gota espessa/QBC Test® ou detecção de antígenos parasitários. The aim of the present work was to establish appropriate criteria for screening of donor blood from regions with distinct Malaria epidemiological characteristics. Three locations with different screening criteria were studied: São Paulo, SP (with no vectorial transmission), Belém, PA (with low active transmission) and Matupá and Peixoto de Azevedo, MT (with high active transmission). The Malaria parasite3/4Plasmodium sp3/4was searched for by "thick film", QBC Test( and antigen Immunofluorescence test, and was not detected in any of the samples. There was, however, a great variation in the positivity of anti-plasmodial antibodies, as determined by IIF-IgG anti-P. vivax and -P. falciparum, between accepted donors in the 3 studied locations and between rejected and accepted donors in São Paulo (1.98% accepted, 22.3% rejected - p < 0.01) and Belém (17.2% accepted, 58.3% rejected - p < 0.01). These data endorse the use of the applied clinical and epidemiological screening. In Matupá and Peixoto de Azevedo, where there was no rejected donor, the serological positivity was 80.6%. We, therefore, consider that the Malaria screening in blood banks should follow clinical and epidemiological criteria suitable to each region. The laboratorial screening techniques should then detect either the parasites (thick film/ QBC Test® or the parasite antigens.