Immunogenicity of three different influenza vaccines against homologous and heterologous strains in nursing home elderly residents.

We studied whether MF59-adjuvanted influenza vaccine improves immunity against drifted influenza strains in institutionalised elderly with underling chronic health conditions. Sera from a randomized study, comparing MF59-adjuvanted (Sub/MF59, n = 72), virosomal (SVV, n = 39), and split (n = 88) vaccines, were retested using a hemagglutination inhibition (HI) assay against homologous (Northern Hemisphere [NH] 1998/99) and drifted (NH 2006/07) strains. Corrected postvaccination HI antibody titres were significantly higher with Sub/MF59 than SVV for all strains; GMTs against homologous A/H3N2 and B and both drifted A strains were significantly higher for Sub/MF59 than split. Seroprotection rates and mean-fold titer increases were generally higher with Sub/MF59 for all A influenza strains. MF59-adjuvanted influenza vaccine induced greater and broader immune responses in elderly people with chronic conditions, than conventional virosomal and split vaccines, particularly for A/H1 and A/H3 strains, potentially giving clinical benefit in seasons where antigenic mismatch occurs.

Varicella: epidemiological aspects and vaccination coverage in the Veneto Region.

BACKGROUND: With the control of many infections through national vaccination programmes, varicella is currently the most widespread preventable childhood disease in industrialized nations. In 2005 varicella vaccination was added to the Veneto Region routine immunization schedule for all children at 14 months of age and 12 year-old susceptible adolescents through an active and a free of charge offer. To evaluate parameters at the start of the programme, we conducted a study to describe the epidemiology of varicella infection and coverage rates for varicella vaccine in the Veneto Region (North-East Italy). METHODS: We examined incidence rates and median age of case patients in the Veneto Region for 2000-2007 period using two data sources: the mandatory notification of infections diseases and the Italian Paediatric Sentinel Surveillance System of Vaccine Preventable Diseases. Corrected coverage rates were calculated from data supplied by the Public Health and Screening Section of the Regional Department for Prevention. RESULTS: In the Veneto Region from 2000 to 2007, a total of 99,351 varicella cases were reported through mandatory notifications, mostly in children under 15 years of age. The overall standardised annual incidence ranged from 2.0 to 3.3 per 1,000 population, with fluctuations from year to year. The analysis by geographic area showed a similar monthly incidence rate in Italy and in the Veneto Region. The vaccination average adherence rate was 8.2% in 2004 cohort, 63.5% in 2005 cohort and 86.5% in 2006 cohort. Corrected coverage rates were 8.1% in 2004 cohort, 59.9% in 2005 cohort and 70.0% in 2006 cohort, respectively. CONCLUSION: Data from passive and active surveillance systems confirm that varicella is a common disease which each year affects a large proportion of the population, mainly children. Uptake of the varicella vaccination programme was strikingly good with average coverage rates of about 70% after only 3 years. Sustained implementation of existing vaccine policies is needed to warrant any significant reduction of varicella incidence in the Veneto Region. Continued surveillance will be important to monitor the impact of the recently introduced mass vaccination policy.

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.

Response to influenza vaccine in people with non-protective HI antibody titers.

The purpose of the study was to determine which factors correlate directly with response to vaccination in such a group of subjects with non-protective HI antibody titers before vaccination. Two vaccines were used, a subunit virus vaccine adjuvanted with MF59 and a split virus vaccine. The analysis indicated that immunization with vaccine adjuvanted with MF59 was an independent variable for immune response against A/H3N2 (OR: 3.51; 95% CI: 1.81-6.79) and B (OR: 2.31; 95% CI: 1.37-3.89). The results suggest that antibody response to vaccine is satisfactory in elderly people previously lacking a protective antibody titer, and that the adjuvanted vaccine reveals a better immunogenicity.

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.

Object-oriented influence diagram for cost-effectiveness analysis of influenza vaccination in the Italian elderly population.

Influenza infection is a major cause of illness, morbidity and mortality throughout the world, mainly amongst the elderly. Since vaccination has proven to be effective in the reduction of all acute complications, deciding whether to implement a vaccination campaign and which vaccine to prescribe is an important task. The aim of this review is to build a decision model, which allows the decision makers to evaluate the possible results under different scenarios, and to choose the decision associated with the highest expected utility. The analysis is based on Bayesian networks methodology. Vaccination is more effective in the long run and is cost saving compared with the null option. Moreover, the innovative MF59 adjuvanted flu vaccine proves to be cost effective with respect to standard vaccines.

Long-term persistence of anti-HBs after vaccination against HBV: an 18 year experience in health care workers.

The aim of the present study was to evaluate the long-term persistence of seroprotection after hepatitis B virus (HBV) vaccination. A total of 422 health care workers (HCWs) were evaluated 4.8-18.8 years after primary immunization (mean follow-up 11.8 years); 241 of them had received plasma-derived vaccines and 181 had been given yeast-derived vaccines; 107 subjects received a booster dose of yeast-derived vaccine 6 years after primary immunization with either plasma-derived or yeast-derived vaccines. Seroprotection was assumed when the anti-HBs titers were >10 mIU/ml. The overall response after primary immunization was 98.8%. Among subjects who reached a 10 year follow-up, those treated with plasma-derived vaccine had a seroprotection rate of 87.8 compared to 81.6% of those vaccinated with yeast-derived vaccines (P<0.001). Anti-HBs geometric mean titers (GMTs) after primary immunization were similar in the two groups, but were significantly lower at 10 years follow-up in the group that had received a yeast-derived vaccine (104 mIU/ml versus 244 mIU/ml in those who used a plasma-derived vaccine, P<0.05). Anti-HBs GMTs in the 107 subjects given the booster dose were 242 mIU/ml pre-booster titer, and rose to 35,171 mIU/ml after the booster dose. A mean 10.1 years after the booster dose, GMTs were 952 mIU/ml. Overall, the anti-HBs seroprotection rate was 95.4% (102 subjects). Based on GMT results, no booster dose is necessary in healthy adults for at least 10 years after primary immunization.

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.

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.