ABSTRACT
HBV infection is endemic in Brazil and acute HBV infection is still a common disease. Objective: To analyze incidence, risk factors and evolution of acute HBV infection. Setting: University Hospital. Patients: 357 patients with acute HBV infection, comparing two periods: 1985-1989 vs. 1990-1994. Results: The overall incidence declined from 50 new cases/year in 1985-89 (30 per cent of all cases) to 25 new cases/year in 1990-94 (8 per cent of all cases). Transmission among male homosexuals (3.9 per cent of cases in 85-89) declined to 1.3 per cent in 90-94 (p>0.05). Amongst health care workers (HCW) it declined from 8.2 per cent to 2.0 per cent (p=0.02). Conversely, heterosexual transmission increased from 4.8 per cent to 10.1 per cent (p=0.06). Chronification of HBV infection following the acute episode was observed in 1.7 per cent. Fulminant hepatic failure was seen in 3.4 per cent. However, 27.2 per cent of patients were lost to follow-up before normalization of the biochemical tests. Conclusions: The different patterns of risk factors observed is probably related to measures for preventing AIDS and to HCW vaccination programs. Chronification following acute episodes was not a common event.