Anti-HCV related to HCV PCR and risck factors analysis in a blood donor population of central Brazil

Ainda sao raros os casos de infeccao por hepatite C (HCV)na regiao central do Brasil. Neste estudo, 2.350 doadores voluntarios de sangue foram avaliados, resultando em prevalencias para o anti-HCV de 2,2 (por cento), pelo ELISA de segunda geracao, e de 1,4 por cento, apos o ensaio confirmatorio "line immunoassay". Anticorpos contra os antigenos "core", NS4 e NS5 do HCV foi observada em 76,6 (por cento) dos doadores anti-HCV positivos. A positividade da reacao em cadeia da polimerase (PCR) mostrou-se relacionada a reatividade aos diferentes antigenos do HCV no "line immunoassay". A maioria dos doadores positivos tiveram historia previa de exposicao parenteral. A combinacao de ALT>50 UI/1 e positividade ao anti-HBc parece nao ser eficaz como marcadores indiretos para a infeccao pelo HCV, entretanto a dosagem do ALT e a deteccao de anti-HCV sao indicadas na triagem de doadores de sangue brasileiros.

Human antibodies to dengue and yellow fever do not react in diagnostic assays for hepatitis C virus

Hepatitis C virus (HCV) is a recently described causative agent of the great majority of post-transfusion non A-non B hepatitis and is classified within the Flaviviridae family. Due to a high prevalence of anti-HCV and other flaviviruses circulating in Brazil, such as dengue and yellow fever, we investigated the possibility of serological cross-reactivity between these viruses. Different panels of human sera positive for dengue type 1 (9 cases) and type 2 (7 cases) from 6 patients naturally infected with yellow fever and from 94 adults vaccinated against the 17D strain of yellow fever were tested against HCV antigens used in diagnostic assays. Two enzyme immunoassay systems were tested: one, an in-house test using recombinant antigens from core, NS3 and NS5 regions of the HCV genome (Research Foundation for Microbial Disease of Osaka University, Japan); and another, using synthetic peptides representing immunodominant epitopes of structural core and non-structural NS4 and NS5 HCV regions (INNOTEST HCV Ab, Innogenetics, Belgium). A line immunoassay (INNO-LIA HCV Ab, Innogenetics, Belgium) was used as a confirmatory test. In this, HCV antigens are coated as discrete lines on a nylon strip with plastic backing. Besides 4 control lines on each strip, a total of 6 HCV lines are present: line A consists of several NS4 epitopes, line B consists of several NS5 epitopes and lines C-F contain several core epitopes. This test not only confirms but differentiates antibodies to hepatitis C virus. No positive results were detected with these tests, indicating that hepatitis C infection can be evaluated by current assays in regions where flaviviruses are endemic