O objetivo deste estudo foi avaliar, pela hemocultura e PCR, os resultados do teste ELISA utilizado para doença de Chagas na triagem de doadores de sangue na rede pública do Estado do Paraná, Brasil, e traçar o perfil epidemiológico dos doadores quanto ao risco de infecção pelo Trypanosoma cruzi. Os resultados negativos e positivos do ELISA foram confirmados pela hemocultura e PCR em 190/191 indivíduos (99,5%). Para um indivíduo (0,5%), o teste de ELISA foi inconclusivo, hemocultura e IFI foram negativas, HAI e PCR foram positivas. Três indivíduos (1,6%) foram positivos para T. cruzi em todos os testes. A maioria dos doadores era do sexo feminino, oriundos do Estado do Paraná, de origem rural, tinham observado ou foram informados da presença do vetor nos municípios onde residiam, nunca tinham recebido sangue, haviam doado sangue de 1 a 4 vezes e não relataram casos de doença de Chagas na família. Nós concluímos que a PCR e a hemocultura são excelentes testes para confirmar os resultados do ELISA e os candidatos a doadores de sangue com testes positivos e negativos apresentam risco semelhante de infecção pelo T. cruzi, reforçando o nível satisfatório de segurança do teste ELISA para liberar o sangue para o uso.

The objective of this study was to evaluate, through blood culture and PCR, the results of the ELISA for Chagas' disease in the screening of blood donors in the public blood-supply network of the state of Paraná, Brazil, and to map the epidemiological profile of the donors with respect to their risk of infection by Trypanosoma cruzi. The negative and positive results of the ELISA were confirmed by blood culture and PCR for 190/191 individuals (99.5%). For one individual (0.5%), the ELISA was inconclusive, blood culture and IIF were negative, and IHA and PCR positive. Three individuals (1.6%) were positive for T. cruzi on all the tests. Donors were predominantly female, and natives of Paraná, of rural origin, had observed or been informed of the presence of the vector in the municipalities where they resided, had never received a blood transfusion, had donated blood 1 to 4 times, and reported no cases of Chagas' disease in their families. We concluded that PCR and blood culturing have excellent potential for confirming the results of the ELISA, and that candidate blood donors with negative or positive tests have a similar risk of infection by T. cruzi, indicating that the ELISA test is sufficiently safe for screening blood prior to use.

Visando a obtenção de informações sobre os casos de malária registrados no Estado do Paraná, analisaram-se os relatórios de atendimento de casos suspeitos de malária elaborados pela Fundação Nacional de Saúde, regional do Paraná, no período de janeiro de 1994 a dezembro de 1999. Das 31.975 amostras de sangue examinadas, 7,4% mostraram-se positivas, sendo 86,4% para Plasmodium vivax; 12,7% para P. falciparum; 0,04% para P. malariae e 0,9% para P. vivax e P. falciparum. Com relação à classificação epidemiológica, 84,5% representaram casos importados e 15,5% casos autóctones. Os municípios com maior número de casos autóctones foram Foz do Iguaçu, Santa Terezinha do Itaipu e Santa Helena, região de influência do lago de Itaipu, onde devem-se, portanto, concentrar os esforços de vigilância.

To collect data regarding registered cases of malaria in the state of Paraná, attendance reports of suspected cases of malaria performed by Fundação Nacional de Saúde, Paraná regional center, were analyzed from January, 1994 through December, 1999. Of 31,975 blood samples examined, 7.4% were positive: 86.4% for Plasmodium vivax, 12.7% for P. falciparum, 0.04% for P. malariae and 0.9% for P. vivax and P. falciparum. As to the epidemiological classification, 84.5% represented heterochthonous cases and 15.5% represented autochthonous cases. The municipalities showing higher rates of autochthonous cases were Foz do Iguaçu, Santa Terezinha do Itaipu and Santa Helena, a region influenced by the Itaipu reservoir, where prevention and control actions must be concentrated.

Giardia duodenalis cysts obtained from fresh fecal samples, fecal samples kept under refrigeration and fecal samples treated with formalin were studied as to their floatability on sucrose solutions with the following specific gravities: 1,040 kg/m3; 1,050 kg/m3; 1,060 kg/m3; 1,070 kg/m3; 1,080 kg/m3; 1,090 kg/m3; 1,100 kgm3; 1,150 kg/m3; 1,200 kg/m3; and 1,250 kg/m3, contained within counting-chambers 0.17 mm high. Cysts that floated on and those settled down as sediments were counted, and had their percentages estimated. Sucrose solutions of 1,200 kg/m3 specific gravity (the average specific gravity of diluting liquids employed in floatation techniques) caused to float 77.7%, 78.4% and 6.6% of the G. duodenalis cysts obtained, respectively, from fresh fecal samples, fecal samples kept under refrigeration, and fecal samples treated with formalin. Cysts obtained both from fresh fecal samples and fecal samples kept under refrigeration presented similar results concerning floatability. It was observed, however, that the treatment of feces with formalin diminished the cysts floatability under the various specific gravities studied. This results should influence, the recommendations for transport and storage of fecal samples used for parasitological coproscopy.