Risk factors for acute parenterally transmitted viral hepatitis: A 20-year study

In order to verify the relative role of each single risk factor during a long period of observation, and to compare the frequency of risk factors in parenterally and non-parenterally transmitted acute viral hepatitis, we studied 1,251 patients admitted to our Department from 1971 to 1991. Acute hepatitis A cases were considered non-parenterally transmitted, whereas B, C, NANB and Delta hepatitis were grouped together as parenterally transmitted. The two groups were compared for age, sex and the following risk factors: surgical procedures, transfusion, dental procedures, intravenous drug addiction, infected partner, infected relative and hospital admission. There were 243 non-parenterally transmitted and 1,008 parenterally transmitted cases. In univariate analysis, mean age in the two groups was 20 and 37 years (p = 0.000001) for non-parenterally and parenterally transmitted cases respectively; mean ages of patients with different parenterally transmitted hepatitis (B, NANB, C, Delta) did not differ significantly (p = 0.35). The following risk factors were significantly more frequent in the parenterally transmitted hepatitis group: surgical procedure (odds ratio = 8.04, 95% confidence intervals: 3.75, 20.51), transfusion (OR= 18.79, 95% Cl: 5.03, 157.72), dental procedures (OR = 2.19, 95% CI: 1.2, 4.06), drug addiction (OR: 11.02: 95% Cl: 4.15, 41.34), and infected partner (OR = 17.61, Cl: 3.02, 708.65). However, logistic regression showed the following factors as being significant: age (p = 0.00001), transfusion (OR = 3.35, 95% CI: 1.61, 6.94), dental procedures (OR = 1.61, 95% Cl: 1.18, 2.2), drug addiction (OR = 4.88, 95% Cl: 2.94, 8.1). Therefore we suggest that, besides considering surgery and - in the near future - transfusion as less important risk factors for acute parenterally transmitted hepatitis, and while continuing social and medical campaigns against drug addiction, special efforts should be concentrated on increasing the use of all possible hygienic measures in dental care.