Avaliação sorológica e epidemiológica para hepatite C dos doadores de sangue do Hemocentro Regional de Uberaba.

Abstract

Even though the development and use by Blood Banks in Brazil of ELISA s tests of third and fourth generation for the detection of anti-HCV with higher sensitivity in relation to the tests of second generation, the specificity of those tests still remains below of the desired one. Therefore, the serological screening for hepatitis C using enzyme immunoassays can present false-positive reactions and lead healthful individuals to have to deal with the stigma of a supposed reacting test, being able to compromise the social relations and to intervene with the daily functions until its diagnostic elucidation. Such situation also takes the discarding of great number of blood bags, with financial losses for the SUS. The aim of our work was to study the serological profile it hepatitis C and to compare its occurrence in first time and repeat donors of the Hemocentro Regional de Uberaba (HRU); to analyze the demographic and social characteristics of the donor in general and to compare with those inapt for positive or undetermined serology for the virus of hepatitis C (HCV); to compare alterations in the levels of transaminase glutamic-pyruvic (TGP) between the apt donors and inapt donors for hepatitis C and to search, on the basis of the confirmatory test, the prevalence of positive serology for hepatitis C, from November of 1992 to December of 2005. The work was carried out using the descriptions of the donors in the archives of the HRU and of handbooks of those who were directed to the hepatitis clinic in University Hospital. For the statistics analysis, the exact test of Fischer or Qui-square for the comparison between the groups was used and the test Mc Nemar for the comparison between the screening tests and the confirmatory one. The results were considered significant when the probability of rejection of the nullity hypothesis was lesser than 5% (p<0,05). In the period of November of 1992 until December of 2005, were done 171027 blood donations in the HRU. Of these, 561 presented not negative serology for hepatitis C, with global occurrence of 0,33%. We observed significantly bigger amount of first time donors between those with serological inaptitude for the HCV when compared with the apt donors, what also was observed in the candidates of the masculine sex. We did not find significant statistical differences between the groups relating the age, color, civil state and place of residence. The biochemist evaluation by dosage of the TGP evidenced bigger number of elevated levels of the enzyme in the inapt in relation to the control group. Moreover, when divided in first time and repeat donors, we observed that this index was significantly higher in the first time donors both in the control and in inapt group. Of the candidates with not negative serology, 24,14% (98) were submitted to the confirmatory examinations for the reaction in chain of polymerase (PCR), and only 34,69% (34) presented positive result. Thus, we observed that a significant number of serological inapt donors, as much anti-HCV positive as indeterminate, had not confirmed the presence of the infection for the HCV, concluding that many times the serological ineptitude for hepatitis C in the HRU does not correspond to the presence of viral infection of the donor. Selecting a test of screening with the maximum of specificity (without compromising sensitivity) and implanting more secure algorithms and confirmatory methods would diminish the number of donors with false-positive reactions having thus prevented results undesirable to the Blood Banks and to the blood donors.