[Acute viral hepatitis in the Florence area: I. Epidemiologic study].

: The sera of 401 patients admitted to the Department of Infectious Diseases [U.S.L. (Unita Sanitaria Locale) 10 D] in Florence in one year were screened for the presence of markers of hepatitis A and B viruses. On the basis of clinical and serological data, the diagnosis of viral hepatitis was confirmed for 302 patients. Among the se, 73 (24.18%) were affected by hepatitis A, 182 (60.26%) by hepatitis B and 47 (15.56%) by nonA nonB hepatitis. The prevalence of B nonA nonB hepatitis in 133 drug addicts was 69.37% and 25.51% respectively. A previous infection with hepatitis A virus, as demonstrated by the presence of anti A antibodies of the IgG idiotype in the sera, was demonstrated in 201 of 328 patients (62.03%) not affected by hepatitis A. Only 14% of them reported data related to a possible former acute hepatitis. Markers of B virus were found in 62 of 167 sera of patients (37.12%) not affected by acute B hepatitis or chronic HBsAg positive hepatitis. However the prevalence of virus B markers increases up to 50% in the sera of drug addicts. According to our data the spreading of virus hepatitis in the area of Florence is similar to that observed in other Regions of Central and Northern Italy with fairly good social and hygienic conditions. High prevalence of nonA nonB hepatitis and of HBsAg carriers among the drug addicts are noteworthy.