ABSTRACT
Background: So that an improvement in the selection of donors can be achieved and the risk to the recipient of transfused blood can be reduced, prospective donors are submitted to clinical and serological screening. Objective: This study investigated the blood discard rate and the rate of infectious and contagious diseases in blood donors from provincial towns of the state of Paraná, Brazil. Methods: This study was an exploratory cross-sectional descriptive investigation with a quantitative approach of donations between January and December 2011. Results: In the study period the Regional Blood center in Maringá, Brazil received 8337 blood donations from people living in the city and neighboring towns. However, 278 (3.33%) donations were discarded during serological screening owing to one or more positive serological markers. A total of 46.4% of the discarded blood units were confirmed positive by serology with anti-HBc being the most common (66.7%), followed by syphilis (22.5%), HBsAg (4.7%), anti-hepatitis C virus (3.1%), human immunodeficiency virus (1.5%) and Chagas' disease (1.5%). The rate of infectious-contagious diseases that can be transmitted by blood transfusions was 1.55% (129/8337) of the donor population with a frequency of 1.03% for anti-HBc and 0.35% for syphilis. Conclusion: This study demonstrates a high prevalence of the anti-HBc marker in prospective blood donors from provincial towns in the state of Paraná, Brazil. .
Subject(s)
Humans , Blood Banks , Blood Safety , Blood Donors/statistics & numerical data , Hemotherapy Service , Hepatitis C/transmission , Biomarkers , Quality Control , Serology , BrazilABSTRACT
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 percent). For one individual (0.5 percent), the ELISA was inconclusive, blood culture and IIF were negative, and IHA and PCR positive. Three individuals (1.6 percent) 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.
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 por cento). Para um indivíduo (0,5 por cento), o teste de ELISA foi inconclusivo, hemocultura e IFI foram negativas, HAI e PCR foram positivas. Três indivíduos (1,6 por cento) 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.
Subject(s)
Blood Chemical Analysis , Blood Donors , Chagas Disease/blood , Enzyme-Linked Immunosorbent Assay/methods , Polymerase Chain Reaction/methods , Blood/parasitology , Chemical Phenomena , Diagnosis/analysis , Diagnosis/methods , Trypanosoma cruzi , Hematologic Tests/methodsABSTRACT
This paper studies the relation between genetic and biological diversity of natural populations of Trypanosoma cruzi (in Parana State, Brazil) isolated from humans (H), classified as T. cruzi II, and from sylvatic reservoirs (G) and triatomines (T), classified as T. cruzi I. Twenty-five biological parameters were evaluated concerning the kinetic of growth and of metacyclogenesis in mediums LIT and M16, to the infectivity to BALB/c mice, and to the susceptibility to benznidazole. The data support the conclusion of a weak relation between genetic distance and biological diversity using strains. The statistical comparison of the means of each parameter, with regard to the different hosts, showed that group T. cruzi II (H) was significantly different from group T. cruzi I (G and/or T) in 13 of the 25 parameters studied: group H differed from G and T in three parameters, and from G or T in 10 parameters. The major differences found in those parameters were related to the kinetic of growth and of metacyclogenesis. One biological implication from these differences is that the lowest growth of parasite observed in group T. cruzi II (H) makes parasitological diagnoses more difficult and provides lower pathogenicity for mice.
Este trabalho estudou a relação entre diversidade genética e biológica de populações naturais de Trypanosoma cruzi do Estado do Parana, isoladas de humanos (H), classificadas como T. cruzi II, e de reservatórios silvestres (G), e triatomíneos (T) classificadas como T. cruzi I. Foram avaliados 25 parâmetros biológicos relacionados à cinética de crescimento e de metaciclogênese em meios LIT e M16, à infectividade em camundongos BALB/c e à suscetibilidade ao benznidazol. Os achados falam a favor de uma fraca relação entre distância genética e diferenças biológicas utilizando cepas. A comparação estatística entre as médias de cada parâmetro, considerando os diferentes hospedeiros, mostrou que o grupo T. cruzi II (H) foi significativamente diferente do grupo T. cruzi I (G e/ou T) em 13 dos 25 parâmetros estudados, onde o grupo H diferiu de G e T em 3 parâmetros e de G ou T em 10 parâmetros. As maiores diferenças ocorreram nos parâmetros relacionados à cinética de metaciclogênese e de crescimento. Entre as implicações biológicas destas diferenças, o crescimento mais lento de parasitas do grupo T. cruzi II (H) prejudica o diagnóstico parasitológico e proporciona menor patogenicidade para camundongos.
ABSTRACT
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 percent, 78.4 percent and 6.6 percent 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