Carriage rates and risk factors during an outbreak of invasive meningococcal disease due to Neisseria meningitidis serogroup C ST-11 (cc11) in Tuscany, Italy: a cross-sectional study.

BACKGROUND: During 2015-2016 an outbreak of invasive meningococcal disease due to N. meningitidis serogroup C ST-11 (cc11) occurred in Tuscany, Italy. The outbreak affected mainly the age group 20-30 years, men who have sex with men, and the area located between the cities of Firenze, Prato and Empoli, with discos and gay-venues associated-clusters. A cross-sectional-survey was conducted to assess the prevalence and risk factors for meningococcal-carriage, in order to address public health interventions. METHODS: A convenience sample of people aged 11-45 years provided oropharyngeal swab specimens and completed questionnaires on risk factors for meningococcal carriage during a 3 months study-period, conducted either in the outbreak-area and in a control-area not affected by the outbreak (cities of Grosseto and Siena). Isolates were tested by culture plus polymerase chain reaction. Serogroup C meningococcal isolates were further characterized using multilocus sequence typing. Univariate and multivariate analyses were performed to estimate adjusted odds ratios (AORs) for meningococcal carriage. RESULTS: A total of 2285 oropharyngeal samples were collected. Overall, meningococcal carriage prevalence was 4.8% (n = 110), with nonencapsulated meningococci most prevalent (2.3%; n = 52). Among encapsulated meningococci, serogroup B was the most prevalent (1.8%; n = 41), followed by serogroup Y (0.5%; n = 11) and serogroup C (0.2%; n = 4); one carrier of serogroup E and one of serogroup Z, were also found (0.04%). Three individuals from the city of Empoli were found to carry the outbreak strain, C:ST-11 (cc11); this city also had the highest serogroup C carriage prevalence (0.5%). At the multivariate analyses, risk factors for meningococcal carriage were: illicit-drugs consumption (AOR 6.30; p < 0.01), active smoking (AOR 2.78; p = 0.01), disco/clubs/parties attendance (AOR 2.06; p = 0.04), being aged 20-30 years (AOR 3.08; p < 0.01), and have had same-sex intercourses (AOR 6.69; p < 0.01). CONCLUSIONS: A low prevalence of meningococcal serogroup C carriage in an area affected by an outbreak due to the hypervirulent N. meningitidis serogroup C ST-11 (cc11) strain was found. The city of Empoli had the highest attack-rate during the outbreak and also the highest meningococcal serogroup C carriage-prevalence due to the outbreak-strain. Multivariate analyses underlined a convergence of risk factors, which partially confirmed those observed among meningococcal outbreak-cases, and that should be considered in targeted immunization campaigns.

Acute hepatitis B 14 years after the implementation of universal vaccination in Italy: areas of improvement and emerging challenges.

BACKGROUND: Italy had intermediate-level endemicity for hepatitis B virus (HBV) infection in the 1970s and 1980s. In 1991, vaccination of infants and adolescents became mandatory. We report the impact of universal vaccination 14 years after its beginning. METHODS: We performed a case-control study within a population-based surveillance for acute viral hepatitis. The incidence of acute hepatitis B (AHB) was estimated for the time since 1991, and the association between AHB and the considered risk factors was analyzed for the period 2001-2005. RESULTS: The incidence of AHB progressively decreased from 1991 to 2005, mainly for persons in the age groups targeted by the universal vaccination campaign: there was a 24-fold and 50-fold decrease in the 15-24-year and 0-14-year age groups, respectively; for the > or =25-year age group, the incidence halved. Owing to the persons' ages, approximately 3% of total AHB cases should have been the target of vaccination campaign. In 2004-2005, foreigners accounted for 14% of total cases and for 57% of persons who should have been targets for vaccination. Missed opportunities for immunization were documented for approximately 50% of patients with AHB who reported cohabitation with HBV carriers and for 70% of those who reported injection drug use. The strongest associations with AHB were found for blood transfusion (adjusted odds ratio [OR(adj)], 8.4; 95% confidence interval [CI], 2.7-26), cohabitation with HBV carriers (OR(adj), 5.3; 95% CI, 3.6-7.7), injection drug use (OR(adj), 3.8; 95% CI, 2.5-5.8), and unsafe sexual practices (OR(adj), 2.8; 95% CI, 1.9-4.2). CONCLUSION: Universal vaccination has contributed to a decreasing AHB incidence in Italy, especially by reducing the risk of infection among persons aged 15-24 years. Most infections occur in persons aged > or =25 years in association with injection drug use, unsafe sexual activity, percutaneous treatment, and iatrogenic exposure. Improvement of vaccine coverage in high-risk groups and adherence to infection control measures during surgery and percutaneous treatment are needed. The high risk still associated with blood transfusion needs to be further investigated, with consideration of occult HBV infection in blood donors. The potential spread of HBV infection from the immigrant population deserves adequate health policy prevention programs.