R. Trivello

Epidemiology of HCV Infection

It is estimated that approximately 130-170 million people worldwide are infected with hepatitis C virus (HCV). According to data from WHO community and blood donor surveys, the African and Eastern Mediterranean countries report the highest prevalence rates (>10%). The rates of infection in the general population and the incidence of newly-acquired cases indicate an appreciable change in the epidemiology of the infection in recent years. Prior to the widespread screening of blood donations, infected blood and blood products represented a common source of infection. On the other hand, the high peak in HCV antibodies among the elderly in Italian epidemiological studies on the population at large reflects a cohort effect due to an epidemic of HCV infection occurring after the Second World War. According to data reported by the CDC Surveillance System, the incidence of acute hepatitis C has declined since the late 1980s. In 2005, as in previous years, the majority of such cases in North America and Northern Europe occurred among young adults and injected drug use was the most common risk factor. Other, less commonly reported modes of HCV acquisition are occupational exposure to blood, high-risk sexual activity, tattooing, body piercing and other forms of skin penetration. Finally, the overall rate of mother-to-child transmission from HCV-infected, HIV-negative mothers has been estimated at around 5% (coinfection with HIV raises this figure to 19.4%). HCV prevention relies on identifying and counseling uninfected persons at risk of contracting hepatitis C.

Changing epidemiology of HCV and HBV infections in Northern Italy: a survey in the general population.

Aim To evaluate the hepatitis B virus (HBV) and the hepatitis C virus (HCV) epidemiology in the general population of Northern Italy, a cohort of 965 subjects, all residents (including 47 immigrants), were anonymously tested for HBV and HCV infections. Material and Methods Serum samples were assayed for anti-HCV and anti-HBV markers by enzyme-linked immunosorbent assay and for HCV-RNA by polymerase chain reaction, and the positive cases were genotyped. HBsAg-positive cases were assayed for HBeAg/anti-HBe, whereas HBsAg negatives were tested for both anti-HBc and anti-HBs. Results The overall prevalence of anti-HCV was 2.6%, with a bimodal distribution characterized by the highest prevalence (12%) in subjects over 75 years old. None of the subjects under 25 years old was anti-HCV positive. Anti-HCV positivity was similar in males and females (2.4% vs. 2.7%). HCV-RNA was positive in 40% of cases and genotype 1 was the most common. The HBsAg prevalence was 1%, with a significant difference according to country of origin (0.8% in Italian subjects vs. 6.4% in immigrants, P=0.01). HBsAg positivity increased significantly with age (R2=0.57, P<0.02). The overall percentages for the prevalence of isolated anti-HBs, anti-HBs+/anti-HBc+, and isolated anti-HBc were 23.8%, 8.4%, and 4.2%, respectively. Conclusions Our study provides a new picture of HCV and HBV epidemiology in Northern Italy, with these features: (1) a cohort effect showing a reduction of HCV infection in the elderly, possible due to age-related mortality; (2) an unchanged overall prevalence of HBV infection, despite continuing immigration of subjects from endemic countries.

Occupational risk of blood-borne viruses in healthcare workers: a 5-year surveillance program.

OBJECTIVE This study presents the results of a 5-year surveillance program involving the prospective follow-up of healthcare workers (HCWs) in the Veneto region of Italy exposed to blood-borne viruses. DESIGN All HCWs who reported an occupational exposure to blood-borne infection joined the surveillance program. Both HCWs and patients were tested for viral markers (hepatitis B surface antigen [HBsAg], antibody to hepatitis B surface antigen [anti-HBs], antibody to hepatitis B core antigen [anti-HBc], antibody to hepatitis C virus [anti-HCV], HCV RNA, and antibody to human immunodeficiency virus [HIV]) and had these markers plus transaminases assayed at 3, 6, and 12 months and then yearly thereafter. Moreover, a program of hepatitis B virus (HBV) prophylaxis was offered to those whose anti-HBs levels were less than 10 IU/mL. PARTICIPANTS Two hundred forty-five HCWs (156 women and 89 men) with a mean age of 37 (+/- 10) years who reported occupational exposure during the 5-year period. RESULTS At the time of exposure, 1 HCW was positive for HBsAg (0.4%) and 2 were positive for HCV RNA (0.8%). Among the patients involved, 28 (11.4%) were positive for HBsAg, 68 (27.8%) were positive for HCV RNA, 6 (2.4%) were positive for HIV, and 147 (60.0%) were negative for all viral markers (4 patients were positive for both HCV and HIV). During the follow-up period after exposure (mean, 2.7 [+/- 1.6] years), there was no increase in transaminases or seroconversions to any of the viral markers. CONCLUSION Our accurate postexposure follow-up revealed a lack of transmission of HBV, HCV, and HIV.

Comparison of three different influenza vaccines in institutionalised elderly.

The reactogenicity and the humoral immune response to three influenza vaccines were evaluated in a randomised, double-blind trial at nursing homes in north-east Italy in winter 1998-1999. Of the 285 subjects, who completed the follow-up, 93 were administered virosomal vaccine, 99 received MF59-adjuvanted vaccine and 93 had split vaccine. Ten subjects (0.3%) reported local and/or systemic reactions in the first week after immunisation. After 4 weeks, protection rates (> or = 40) were near 100% for the H1N1 and B strain and 76.0% against H3N2. The MF59-adjuvanted vaccine group had higher geometric mean titres than the other two. However, the true clinical benefit of the new adjuvanted vaccine should be further substantiated by comparative protective studies. Our results suggest that immune response to influenza vaccination in institutionalised elderly is satisfactory.

Epidemiological aspect of traumatic brain injury in Northeast Italy

Background: Traumatic brain injuries (TBIs) remain an important public health problem in developed countries. Hospital records were reviewed to ascertain the epidemiology of TBIs in Northeast Italy. Methods: The annual rates of TBI-associated hospitalisation were estimated by analysing data collected from hospital records from 1996 to 2000. TBIs were identified according to the Centers for Disease Control and Prevention definition and the ICDMAP-90 was used to assess their severity. Findings: 55,368 TBIs were collected between 1996 and 2000, with an overall 29.4% decline in the number of cases. As for severity, moderate TBIs dropped by 34.1%, whereas a less conspicuous decline was observed for mild injuries. Severe injuries remained stable between 1996 and 1999, but rose in 2000, when the unclassified injuries were better distributed. Concerning outcome, fatal TBIs dropped slightly, but only in 2000. Causes of TBI were recorded in 59.2% of cases: 48.5% were motor vehicle accidents, 8.8% occurred at work and 12.2% at home. There were more males than females in all age groups. The highest number of cases per 100,000 person of motor vehicle accidents was recorded among 16–25 year-old and 36.5% occurred at weekends. Domestic accidents showed two age peaks, in children and the elderly. Occupational accidents occurred at all working ages, tending to decline with older age. Interpretation: Better health care and educational campaigns may have contributed to the declining rate of TBI-associated hospitalisation. Special efforts should be made to further reduce the motor vehicle accidents involving young people and welfare programs are needed to limit the risk of falls and contain functional impairment in the elderly.

Influenza vaccines: Antibody responses to split virus and MF59-adjuvanted subunit virus in an adult population

The humoral immune response generated by two commercial influenza vaccines was evaluated in a randomised, double-blind trial performed in the Public Department of Dolo Health District (North-east Italy) during the winter season 1997–1998. Ninety-eight subjects were immunised with a split virus vaccine and ninety-six with a MF59-adjuvanted subunit virus vaccine (SU/MF59). The pre- and postvaccination (∼30 days) antibody titres were determined by hemagglutination inhibition test (HI). After immunisation protective titre rates (≥ 1:40) were near 100% against virus A strain and 82.5% against B strain. Both vaccines caused significant rises in geometric mean antibody titres (GMTs); however, people who received SU/MF59 vaccine were found to develop a greater immune response compared to the group immunised with SVV. According to logistic regression analysis the unprotective prevaccination immune status and the use of SU/MF59 were identified as independent factors significantly increasing the response to immunisation.

Intrafamilial transmission of hepatitis C virus infection.

Background: The role of intrafamilial HCV transmission is still controversial. Methods: An overall sample of 2856 consecutive HCV-infected patients was studied. All index cases were interviewed to identify potential risk factors for transmission and underwent the following tests: HBsAg, anti-HBc, HIV, and, qualitative HCV-RNA and genotyping. Results: Coinfection with HBsAg was recorded in 4.7%, and with HIV in 2.6% of the HCV-infected index cases. Anti-HCV was detected in 2.1% of the members of their original families, and in 13.8% of 2662 sexual partners. The overall rate of infection for offspring was 2.3%, but the risk was significantly higher when the index case was female. The risk for sexual partners was significantly higher when the risk factor for the index case was intravenous drug (IVD) use rather than blood transfusion. Logistic regression analysis showed that female gender and drug addiction in sexual partners of index case were independent factors significantly associated with HCV transmission to sexual partners. Conclusions: Among all family members of index cases, sexual partners of IVD users were at greatest risk of HCV infection. Sexual transmission may not be the main route of transmission though, since IVD use in the sexual partners themselves was independently associated with HCV infection.

Persistence of anti-HBs antibodies in health care personnel vaccinated with plasma-derived hepatitis B vaccine and response to recombinant DNA HB booster vaccine

Long-term persistence of specific antibodies after primary immunization against HBV infection has been reported. In this study, we evaluated the persistence of anti-HBs in vaccinees 6 years after primary immunization and the response to a booster dose using a recombinant DNA yeast-derived HB vaccine. An 85.4% seroprotection rate was observed after 6 years with a significantly higher seroprotective rate in those subjects who received four doses of vaccine primary immunization as compared with those who received three doses (93.9% versus 67.2%, p < 0.001). One month after receiving the booster dose, 98.6% of the subjects had an anamnestic type of response. The GMTs were found to decrease progressively with increasing age. The antibody levels after booster dose were higher than those attained at the end of primary immunization and reflected the trend seen before the administration of the booster. These results are consistent with the existence of an effective immunological memory in HB vaccine responders. Subjects who received four doses during primary immunization were better seroprotected and had a higher seroprotection rate after the booster dose.

Prevalence of Antibodies against Hepatitis C Virus in the Elderly: A Seroepidemiological Study in a Nursing Home and in an Open Population

Background: The prevalence of antibodies against hepatitis C virus (anti-HCV) increases in the general population with advancing age. Several discrepancies exist in the epidemiology of HCV, however, when selected elderly population groups are tested. Objective: To evaluate the HCV prevalence in two groups of elderly people living in the same geopgraphical area of northeast Italy, i.e., one including residents of a nursing home, the other including subjects living at home. Methods: The overall sample included 496 subjects (mean age 79.31 ± 8.9 years); 288 were in a nursing home, and 208 were living at home. Enrollment in the latter group was based on all subjects over 65 years old listed under the public health service in the same district. The overall rate of adhesion to the study was 90%. Each subject was administered an anonymous questionnaire testing sociodemographic data and risk factors for HCV infection. Serological tests included: anti-HCV and hepatitis B virus serum markers. Multiple logistic regression analysis was performed to evaluate risk factors for anti-HCV positivity. Results: Anti-HCV positivity was found in 34 of 288 (11.8%) elderly in the nursing home and in 23 of 208 (11.1%) in the open population. When the total population was considered, females exhibited a significantly a higher prevalence of anti-HCV than males (13.4 vs. 7.5%, p < 0.05). In both males and females, the highers rate of anti-HCV prevalence was found among the 75- to 79-year-old subjects. A decline in anti-HCV prevalence was observed in the very old subjects (over 80 years of age). None of the anti-HCV-positive subjects was found to be coinfected with hepatitis B surface antigen. However, multiple logistic regression analysis identified the age group between 70 and 79 years, female gender, and positivity for antihepatitis B surface antigen and/or antihepatitis B core antigen as independent variables significantly associated with HCV prevalence. Conclusions: The prevalence of anti-HCV proved identical among elderly people living in the nursing home or at home, suggesting that nursing homes do not represent a risk factor for HCV infections; the significant association between HCV prevalence and antihepatitis B surface antigen and/or antihepatitis B core antigen positivity supports a common route of transmission of the two viruses; these findings would suggest that there was an epidemic of HCV infection during the Second World War and in the years immediately afterwards.

Hepatitis C virus, hepatitis B virus and human immunodeficiency virus infection in pregnant women in North-East Italy: A seroepidemiological study

Background: Pregnant women can be considered a sentinel population, because they are a relatively unselected population whose prevalence data may be extended to the general population. Methods: A seroepidemiological study was carried out in Padua (North-East Italy) to assess the epidemiological aspects of HCV, HBV and HIV infection in 2059 pregnant women consecutively seen at the Department of Obstetrics and Gynaecology during 1996. Out of them, 1804 (87.2%) were indigenous and 255 (12.8%) immigrants. Sociodemographical and sanitary data were collected for each woman. Results: The overall prevalence of anti-HCV was 1.9% (42.5% with detectable HCV-RNA); HBsAg was found in 1.0%; the prevalence of anti-HIV was 0.3%. Findings are substantially consistent with the epidemiological picture of such infections in the general population of our geographic area. A parenteral risk factor for HCV infection was found in 19 subjects (47.5%): 18 were intravenous drug users and 1 a blood transfusion recipient. HBsAg seroprevalence was higher in immigrants than in autochthonous (3.1% vs. 0.7% respectively, p < 0.01). One of the 6 anti-HIV positive women was intravenous drug user. Logistic regression analysis was carried out for each viral agent to determine which characteristics were independently associated with infection: anti-HCV prevalence resulted independently associated to Italian origin (OR: 3.7), unmarried status (OR: 2.7), unemployed condition (OR: 6.1) and history of previous abortion (OR: 2.8). HBsAg prevalence was independently associated to unemployed condition (OR: 10.8), whereas HIV positivity was significantly related to the unmarried status (OR: 18.5). Conclusion: Our study pinpoints the need of screening all pregnant women for HCV and HIV infection, in addition to the HBsAg screening which is compulsory in Italy.