The impact of the hepatitis B mass immunisation campaign on the incidence and risk factors of acute hepatitis B in Italy.

BACKGROUND/AIMS: This study aimed to evaluate the impact of the campaign for hepatitis B mass immunisation of children and teenagers, introduced in 1991, on the incidence of and risk factors for hepatitis B in Italy. METHODS: Hepatitis B cases reported to the surveillance system for type-specific acute viral hepatitis (SEIEVA) during the period 1987-1997 were used to estimate incidence. To assess the association between potential risk factors and hepatitis B cases, hepatitis A cases generated by the same surveillance system were used as controls. RESULTS: During the period 1987-1997, 8275 acute hepatitis B cases were reported to SEIEVA. Hepatitis B incidence declined from 10.4/100,000 in 1987 to 2.9/100,000 in 1997. The fall was more evident before than after the introduction of compulsory vaccination against hepatitis B. The results of multivariate analysis showed that during the years 1995-1997, blood transfusion, intravenous drug use, surgical intervention, dental therapy, other parenteral exposures, multiple sexual partners, and being in the household of a chronic HBsAg carrier were all exposures independently associated with hepatitis B. CONCLUSIONS: The strong association linking acute hepatitis B with iatrogenic exposures, which are more common in adults, suggests that the present immunisation strategy should be combined with the implementation of non-immunologic preventive measures.

Prevention of hepatitis C in Italy: lessons from surveillance of type-specific acute viral hepatitis. SEIEVA collaborating Group.

Using data from the surveillance system for type-specific acute viral hepatitis, the temporal incidence trend of non-A, non-B acute hepatitis and risk factors for acute hepatitis C have been evaluated in Italy. The association between hepatitis C and the potential risk factors (odds ratios, OR) was estimated using hepatitis A patients as controls. The independent roles of the different risk factors were estimated by multiple logistic regression analysis. The incidence of non-A, non-B acute hepatitis declined from 5 per 100 000 to 1 per 100 000 between 1985 and 1996. Anti-HCV data collected by SEIEVA since 1991 showed that 60% of patients with non-A, non-B acute hepatitis were positive for antibodies to the hepatitis C virus (anti-HCV) at the time of hospitalization. During the 6 months prior to the disease onset, the most frequently reported risk factors were multiple sexual partners, other parenteral exposure and intravenous drug use; transmission by blood transfusion declined from 20% in 1985 to 2% in 1996. On multivariate analysis, intravenous drug use (OR=35.5; 95% CI=23.1-54.4), surgical intervention (OR=4.6; 95% CI=3.3-6.5), dental treatment (OR=1.5; 95% CI=1.1-1.9) and two or more sexual partners (OR=2.2; 95% CI=1.6-3.0) were all independent predictors of hepatitis C. These findings indicate that HCV infection is decreasing in Italy. Intravenous drug use, multiple sexual partners, surgical intervention and dental therapy are the main modes of transmission.

Hepatitis B vaccination coverage among healthcare workers in Italy.

In 1996, the vaccination coverage against hepatitis B virus among 3,157 healthcare workers in Italy was inversely related to the level of hepatitis B virus endemicity in the area of residence. Youngest age and lowest years of employment were independent predictors of the likelihood of vaccine acceptance.

Incidence of and risk factors for hepatitis A in Italy: public health indications from a 10-year surveillance. SEIEVA Collaborating Group.

BACKGROUND/AIMS: This study aimed to evaluate the incidence of and risk factors for acute viral hepatitis A (HAV) in Italy. METHODS: Data were from a surveillance system for type-specific acute viral hepatitis (SEIEVA). To estimate the association of hepatitis A cases with the potential risk factors (Odds Ratios) and the proportion of all hepatitis A cases attributable to a given risk factor (population attributable risk), hepatitis B cases were used as controls. Independent predictors of HAV were estimated by conditional multiple logistic regression. RESULTS: During the period 1985-1994, 25553 viral hepatitis cases were reported. Of these, 6408 (25%) were due to hepatitis A (HAV). HAV incidence declined from 10/100000 in 1985 to 2/100000 in 1987. Since 1991, however, an increase in HAV has been observed. The majority of cases were 15-24 years old; the incidence was higher in males and in subjects residing in southern Italy. Only one death (0.02%) was observed. Shellfish consumption was the most frequently reported risk factor (62%). The proportion of cases reporting personal contact with an icteric case, travel to a high-medium endemic areas, and family contact with a child attending a day-care centre (household of day-care child) was 17%, 19% and 15%, respectively. The results of multivariate analysis showed that shellfish consumption (OR=2.6; 95% CI=2.4-2.9), travel to endemic areas for people residing in northern and central Italy (OR=5.4; 95% CI=4.6-6.2) and household of day-care child (OR=1.2; 95% CI=1.03-1.4), were all types of exposure independently associated with HAV. The estimates of population-attributable risk show that shellfish consumption explained as many as 42.2%, travel to high-medium endemic areas for people residing in northern and central Italy 24.2%, and household of day-care child only 1.4% of all acute hepatitis A cases in Italy. CONCLUSIONS: These findings indicate that HAV in Italy is mainly a food-borne disease. Vaccination against hepatitis A is strongly recommended for travellers to endemic areas.

Case fatality rate of acute hepatitis in Italy: results from a 10 year surveillance.

Using data from the surveillance system for acute viral hepatitis we have evaluated the case fatality rate of viral hepatitis in Italy. 71 deaths (0.3%) occurred among the 21,553 reported acute viral hepatitis cases from 1985-1994. None reported history of exposure to drugs or toxins. The highest case fatality rate was observed for B and NANB hepatitis (0.5%). One death occurred among the 6,353 (0.02%) hepatitis A cases and 1 among the 909 (0.1%) anti-HCV positive NANB hepatitis cases. The case fatality for Delta hepatitis was 0.2% (1/422). Case fatality rate was similar in both sexes; increasing with age; 0.03% were < 15 years of age, 0.1%, 15-24 year-old, and 0.5%, > or = 25 years. Subjects older than 24 years of age accounted for 81.4% of total deaths. Intravenous drug use, blood transfusion and other parenteral exposures were the three most frequent non-mutually exclusive sources of infection reported by subjects who died from B and NANB hepatitis. These findings indicate that the survival rate of acute B and NANB hepatitis is lower than that of acute hepatitis A; moreover in Italy, as in other Western countries, acute HCV seems to cause liver failure only rarely.

Incidence of non-A, non-B and HCV positive hepatitis in healthcare workers in Italy.

In Italy, using figures from a surveillance system for acute viral hepatitis, the incidence rate of acute non-A, non-B hepatitis (NANBH) and hepatitis C virus (HCV) hepatitis cases was evaluated in healthcare workers (HCWs) and the general population of the same age over the period 1988-1994. The NANBH incidence among the general population declined from 4.7/100,000 in 1988 to 2.1/100,000 in 1994; the corresponding figures among HCWs were 12.3/100,000 (RR 2.62; CI 95% = 1.66-4.15) in 1988 and 4.3/100,000 (RR 2.05; CI 95% = 1.13-3.77) in 1994. Since 1991, NANBH cases have been tested for antibodies to HCV (anti-HCV). During the period 1991-1994 the proportion of NANBH cases tested for anti-HCV was 81% (38/47) in HCWs and 85% (1019/1193) in other NANBH cases. A similar proportion of NANBH cases in each group (74% and 70%) were shown to be due to HCV. The incidence rate of HCV positive cases among the general population was 1.3/100,000 in 1991 and 1.8/100,000 in 1994; the corresponding figures among HCWs were 3.7/100,000 (RR 2.85; CI 95% = 1.42-5.92) in 1991 and 3.1/100,000 (RR 1.72; CI 95% = 0.88-3.59) in 1994. The proportion of cases with jaundice was 56.2% in HCWs and 63.7% in the general population. Needlestick injury without major risk factors such as blood transfusion, intravenous drug use or surgical intervention was reported by 12.0% of HCWs and by 0.1% of the general population. Lack of any risk factor was reported by 40.2% of HCWs. These findings strongly suggest that in Italy healthcare workers are at greater risk than the general population of acquiring NANBH, as well as HCV.

Hospitalization rate and mean days of hospitalization of notified viral hepatitis cases in Italy. The Seieva Collaborating Group.

The hospitalization rate and the mean days of hospitalization of notified viral hepatitis cases in Italy were estimated by a specific surveillance system for acute viral hepatitis over the period 1987-1992. The hospitalization rate was very high, ranging from 88.8% for hepatitis A to 90.9% for non-A, non-B hepatitis. No changes were observed over time. For each type of hepatitis the highest figure was observed in the 15-24 year age group. The mean days of hospitalization of hepatitis B (24.2) and non-A, non-B (20.5) hepatitis was significantly higher (p < 0.05) than that of hepatitis A (16.5). The highest mean days of hospitalization of hepatitis A and B occurred in the 0-14 year age group, while for non-A, non-B hepatitis it was observed in subjects over 24 years of age. These findings indicate a nearly similar rate of hospitalization of all types of hepatitis. Hepatitis B and non-A, non-B hepatitis show a more prolonged course than hepatitis A.

Hepatitis B in health workers in Italy.

In Italy, a vaccination campaign against hepatitis B was launched in 1985. It was strongly recommended for health care workers. Over the period 1986-91 the incidence rate of acute B hepatitis in the general population declined from 12/100,000 in 1986 to 5/100,000 in 1991. The corresponding figures among hospital workers were 42.5/100,000 (RR 3.5; 95% CI 2.55-4.92) in 1986 and 14.5/100,000 (RR 2.9; 95% CI 2.03-4.14) in 1991, respectively. The proportion of HBV cases with jaundice was about the same in the general population (77.6%) and in the health care staff (74.2%). Nearly 6% of hospital workers cases had completed the schedule of HBV vaccine. Despite the fact that vaccination against HBV has been strongly recommended for hospital workers, the incidence of infection in this job category has continued to be higher than that in the general population, probably as a consequence of poor vaccine coverage. These findings reiterate the need for aggressive vaccination programmes in hospital workers.