Viral hepatitis - Epidemiology

Epidemiology - SEIEVA data

Epidemiological data as of December 31, 2022

Hepatitis B vaccination: where we are now

In Italy, hepatitis B vaccination is recommended for, and offered free of charge to, all people in at-risk groups and, pursuant to Law 165/1991, all those born since 1980. Every year, however, SEIEVA receives several reports of hepatitis B infection in unvaccinated people from the target groups for vaccination. The figure below shows the number of reported cases of hepatitis B in these target groups, revealing a downward trend over the years (2001-2022): from almost 100 cases a year in the first few years to 14 cases in 2022, despite a slight increase on 2020 and 2021 probably attributable to underreporting during the COVID-19 emergency. Most cases of infection among at-risk groups are still being recorded in people living in the same household as chronic carriers of hepatitis B (green line). This gives food for thought and, once again, highlights the importance of proper communication to continue raising awareness about the benefits of vaccination. It is the duty of healthcare workers to inform patients and members of their household about the disease and the availability of an effective and safe vaccine. As for mandatory vaccination, coverage rates have been suboptimal over the last few years, also falling below the WHO-recommended threshold of 95% (94% in the 2019 birth cohort) (source: Ministry of Health). The percentage of people who slip through the net of mandatory vaccination is not high, but preventable cases of infection continue to be reported every year (6 in 2022 – blue line). Over the last 4 years, no more than 1-2 cases of infection have been reported per year for each of the remaining categories (healthcare workers – red line; drug addicts using public addiction services – purple line): although the target of “zero cases” has not yet been achieved, this proves the effectiveness of prevention strategies in both healthcare settings and addiction services.

Hepatitis A
Hepatitis B
Hepatitis C
Hepatitis E
Additional reports

Hepatitis A

In 2022, 140 cases of hepatitis A were reported to SEIEVA, mostly by health authorities in central and northern regions, such as Lombardy, Tuscany, Lazio, Veneto and Emilia-Romagna. Incidence rose slightly to 0.28/100,000 (from 0.25/100,000 in 2021 and 0.19/100,000 in 2020), mainly due to an increased number of cases in children (incidence 0-14 years: 0.55/100,000). Overall, however, the graph showing the incidence of hepatitis A in Italy over the last 14 years reveals a continuation of the downward trend first recorded after the 2017-2018 outbreak.

In 2022, most cases of infection were recorded in children (0-14 years of age) and elderly people (≥65 years) (37 cases in both age groups). As for gender distribution, men accounted for a higher number of cases.

With regard to risk factors, the graph shows that in recent years hepatitis A has returned to being mainly a foodborne infection, with 36.8% of cases in 2022 reporting consumption of raw or undercooked shellfish (and 23.5% reporting consumption of frozen mixed berries). Among sexually active men, 42.9% of cases reported having sex with other men (MSM, Men who have Sex with Men), the highest percentage since the latest outbreak associated with this risk factor (2016-2017).

In 2022, 1 death attributable to ascites “of unknown origin” was reported in a 94-year-old woman; no cases of fulminant hepatitis, encephalopathy, or cases requiring an organ transplant were notified.

Hepatitis A vaccine

The risk factors can be analysed to identify any preventable cases. In 2022, 30 cases (21.4%) of infection were reported in individuals for whom vaccination was strongly recommended: travellers to endemic areas (29) and people with a history of contact with jaundiced persons (2). Five cases in the MSM category could have been prevented, following the information and vaccination campaigns conducted after the 2016-2017 outbreak.

Hepatitis B

In 2022, 109 cases of acute hepatitis B were reported, mostly by health authorities in central and northern regions, such as Lombardy, Tuscany and Lazio. Incidence (0.22/100,000) was in line with previous years (0.18/100,000 in 2021 and 0.21/100,000 in 2020).

Once again, most cases were recorded in people aged 35-54 years (incidence of disease in 2022: 0.34 per 100,000) and ≥55. Like in previous years, men accounted for a higher percentage of cases (72.5%).

As for risk factors, the findings confirmed recent trends: most cases reported having cosmetic procedures, such as manicure, pedicure, piercing and tattooing (40%, up from previous years), or engaging in promiscuous sexual behaviour (26.0%; on the rise since 2021 after a slight decline probably due to the restrictions imposed during the SARS-CoV-2 pandemic). The percentage of cases reporting a possible healthcare-associated exposure (hospitalization, surgery, haemodialysis or blood transfusion) was also on the rise (18.9%).

In 2022, 3 deaths and 1 case of fulminant hepatitis that ultimately required a transplant were reported. The three deaths were a 55-year-old male kidney transplant patient on immunosuppressive therapy, a 47-year-old man and a 91-year-old woman.

Hepatitis B vaccine

• Four cases of infection were reported in individuals who were fully (3) or partially (1) vaccinated. Of all cases recorded in 2022, 14 were reported in people for whom vaccination was strongly recommended: 2 healthcare workers, 7 people living in the same household as chronic carriers (4 of them were aware of the chronic carrier’s infection), 1 drug addict (who was not using public addiction services) and 4 MSM.

Hepatitis C

In 2022, 55 new cases of acute hepatitis C were reported to SEIEVA (compared to 24 in 2021), with an incidence of 0.11 cases per 100,000 population. As evidenced in the graph showing the incidence of hepatitis C in Italy since 2009, incidence returned to the levels recorded in 2017, after a downward trend that lasted about 10 years. Most cases were reported by region Lazio (41.8%), followed by Lombardy and Veneto.

• Like in previous years, a higher proportion of cases was recorded in men (58%). Almost all cases (51/55, or 92.7%) were aged over 34 years, and 16 cases were ≥65 years.

• Healthcare-associated exposure was identified as the main risk factor (as it’s been the case for the past 20 years), accounting for an increasing percentage of cases (54.0%). Cosmetic procedures (such as manicure, piercing and tattooing) were the second most important risk factor, as the proportion of cases reporting such procedures rose sharply, after falling in 2021, to 38.8%. Sexual exposure, understood here as having multiple sex partners or unprotected casual sex, has played an inconsistent role over the years, and was recently associated with significantly fewer cases, probably as a result of the measures taken to control the SARS-CoV-2 pandemic.

In 2022, only 3 cases of infection were recorded in people living in the same household as chronic carriers of hepatitis C. One death, from septic shock, was reported in a 53-year-old man, while a 52-year-old woman required a liver transplant.

Hepatitis E

In 2022, 44 cases of hepatitis E were reported, mostly by health authorities in central and northern regions (Emilia Romagna, Umbria, Abruzzo and Lombardy). Five of them had travelled to endemic areas, while 39 (88.6%) were local cases.

Most cases (79.5%) were recorded in people aged 35 years or over; 20.4% of all cases were ≥65 years of age. Like in previous years, a higher proportion of cases was recorded in men (70.5%).

As for risk factors, 25.9% of cases reported consuming raw or undercooked pork, and 11.5% raw or undercooked wild boar meat. Travellers to endemic areas reported trips to China, Pakistan (2 cases each) and Jordan (1 case).

In 2022, 2 cases (both of them local) required a transplant.

Additional reports

57 cases of hepatitis of unknown origin in children
7 suspected cases of hepatitis of unknown origin in children (some hepatitis marker results were missing)
1 case of hepatitis D (superinfection) in an 83-year-old man, with no reported risk factors
9 cases of acute hepatitis that tested negative for the most common hepatitis viruses (A, B, C and E)
4 cases of acute hepatitis that tested negative for hepatitis viruses A, B and C, but were not tested for anti-HEV (hepatitis E) IgM, as recommended by EASL, the European Association for the Study of the Liver
29 unclassifiable cases (information on serological tests was incomplete). Nine of them reported taking medications

Note: 18 of the above cases were chronic carriers of HBsAg and had not been tested for anti-HDV IgM.