Soroprevalência das infecções pelos vírus das hepatites B e C em profissionais de hemodiálise do Tocantins / Seroprevalence of hepatitis B and C virus infection in hemodialysis personnel of Tocantins

Para investigar a soroprevalência das infecções pelo vírus da hepatite B (VHB) e da hepatite C (VHC) em profissionais de hemodiálise no Estado do Tocantins, amostras sanguíneas (soros) foram obtidas de 87 por cento (20/23) dos profissionais da única unidade de diálise do Estado, no período de janeiro a março de 2001. As amostras foram testadas para a detecção dos marcadores sorológicos do VHB (AgHBs, anti-HBs e anti-HBc) e VHC (anti-VHC). Encontrou-se a prevalência global de 15 por cento para a infecção pelo VHB. Algumas características de risco foram relatadas pelos profissionais com marcador de exposição a esse vírus, como atividade em hemodiálise por mais de um ano, acidentes de trabalho com objetos perfurocortantes e história de múltiplos parceiros sexuais. Todos referiram vacinação contra hepatite B, sendo detectado o marcador anti-HBs isoladamente em 80 por cento dos indivíduos. Nenhum profissional apresentou positividade ao VHC. Osresultados deste estudo ratificam a importância da transmissão ocupacional do VHB, assim como a baixa eficiência do VHC nessa forma de disseminação.

Hepatitis B and C in the hemodialysis unit of Tocantins, Brazil: serological and molecular profiles

A survey was conducted in the hemodialysis population of the state of Tocantins, Brazil, aiming to assess the prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections, to analyze associated risk factors, and also to investigate these viruses genotypes distribution. During January and March 2001, all patients (n = 100) were interviewed at the unique dialysis unit in Tocantins. Blood samples were collected and serum samples were screened for HBV serological markers. Hepatitis B surface antigen positive samples were tested for HBV DNA. All samples were also tested for anti-HCV antibodies and HCV RNA. An overall prevalence of 45 percent was found for HBV infection (4 percent were HBsAg/anti-HBc positive, 2 percent were anti-HBc only and 39 percent had anti-HBc/anti-HBs markers). Concerning HCV infection, anti-HCV and HCV RNA were detected in 13 percent and 14 percent of the subjects, respectively. Three patients were HCV RNA positive and anti-HCV negative, resulting in an overall HCV prevalence of 16 percent. Univariate analysis of risk factors showed that only shift and length of time on hemodialysis were associated with HBV and HCV positivity, respectively. Among the four HBsAg-positive samples, HBV DNA was detected in three of them, which were identified as genotype A by restriction fragment length polymorphism (RFLP) analysis. All 14 HCV RNA-positive samples were genotyped by INNO-LiPA. Genotypes 1a and 3a were found in 85 percent and 15 percent, respectively. The present data show low HBsAg and HCV prevalence rates. The risk factors associated with HBV and HCV positivity suggest that nosocomial transmission may influence in spreading these viruses in the dialysis unit studied