Long-term persistence of seroprotection by hepatitis B vaccination in healthcare workers of southern Italy.

BACKGROUND: The impact of hepatitis B virus (HBV) vaccination campaigns on HBV epidemiology needs to be evaluated, in order to assess the long-term immunity offered by vaccines against HBV. OBJECTIVES: To evaluate the current status of anti-HBV vaccine coverage among healthcare workers (HCWs) in Southern Italy, and to determine the long-term persistence of antibodies to hepatitis B surface antigens (anti-HBs) in such a cohort of subjects. PATIENTS AND METHODS: A longitudinal, retrospective seroepidemiological survey was conducted among 451 HCWs, who were working at or visiting, the Occupational Health Department of a city hospital, in Catania, Italy, between January 1976 and December 2010. RESULTS: At the 30-year follow-up (mean follow-up 10.15 ± 5.96 years, range 0.74-30), 261 HCWs had detectable anti-HBs titers indicating a persistence of seroprotection of 89.4% (out of 292 anti-HBs positive results, three months after vaccination). An inadequate vaccination schedule was the strongest predictor of antibody loss during follow-up (OR = 8.37 95% CI: 5.41-12.95, P < 0.001). A Kaplan-Maier survival curve revealed that the persistence of anti-HBs 30 years after vaccination, was 92.2% for high responders, while it was only 27.3% for low responders (P = 0.001). CONCLUSIONS: A good level of seroprotection persisted in 57.9% of the subjects after 30 years. Factors related to this immunization status confirmed the importance of vaccinating HCWs early in their careers and ensuring an adequate vaccination schedule. However, with particular reference to the low rate of hepatitis B vaccine coverage among HCWs in Southern Italy, the implementation of a new educational intervention as part of an active vaccination program is needed.

[Drug resistance in endemic and imported tuberculosis cases in Sicily (Italy)]. / Farmacoresistenza in casi di tubercolosi endemici e di importazione in Sicilia.

This study was performed to evaluate the prevalence of anti-tuberculosis (TB) drug resistance in Sicily (Italy). A total of 92 Mycobacterium tuberculosis strains were tested, 43 of which were isolated from outpatients between 2004 and 2007 and 49 isolated from patients hospitalized in various eastern Sicilian hospitals. The 92 strains were all isolated from adult patients (mean age 56 years), 71 of which were Italian and the remaining 21non-Italian. Drug sensitivity testing was performed by using the Canetti proportion method and revealed a large proportion of strains (48.9%) found to be resistant to one or more drugs. The most frequent type of resistance was found to be towards rifampicin (38%). Simultaneous resistance to rifampicin and isoniazid, which characterizes multi-drug resistant TB (MDR-TB), was observed in 19.5% of strains; this was always associated with resistance to at least one other anti-tuberculosis drug. No significant differences were found in the distribution of drug resistance, including multi-drug resistance, between strains isolated from Italian and non-Italian patients. A higher percentage of resistance was found amongst strains isolated from hospitalized patients with respect to those from outpatients: rifampicin 53% vs 21%; isoniazid 41% vs 9%; Mdr-TB 47% vs 12%.

[Surface water pollution and microbiological indicators]. / La contaminazione delle acque superficiali e gli indicatori microbiologici.

Surface waters must undergo careful quality assessment before being used as drinking water. Contamination with wastewaters, whether treated, untreated or partially treated, is a risk to public health. Most waterborne infections are caused by ingestion of contaminated water, but contact or inhalation also represent a risk. In industrialized countries, epidemic episodes are mainly due to the spread of new agents or newly identified infections (Arcobacter, Norovirus, Cryptosporodium, Giardia, etc.). To determine the microbial quality of water environments, the latest regulations identify three different groups of indicators according to their contaminating role: faecal, processing, and model or index organisms. No single organism is an adequate indicator of the diverse conditions of water environments. Thus, it is necessary to accurately identify specific indicators.