Search

This study evaluated the prevalence of anti-legionella antibodies in workers at hospitals with a long-term history of legionella contamination. The hospitals are located in Milan and Turin, northern Italy, and in Naples and Bari, southern Italy. Antibody prevalence and titres of healthcare workers, medical and dental students and blood donors were assessed. In total 28.5% of subjects were antibody positive, most frequently to L. pneumophila serogroups 7-14. Major differences were observed in seroprevalence and type of legionella antibody in persons from different geographic areas. Healthcare workers had a significantly higher frequency of antibodies compared with blood donors in Milan (35.4 vs 15.9%, P

Background: The aims of the study were to detect nosocomial and community-acquired Legionnaires’ disease among patients with pneumonia recovered in Italian hospitals, to improve knowledge on the disease frequency, and to characterise environmental, personal, genetic and immune risk factors associated with the disease appearance (case-control study). Methods: In six big hospitals, an active surveillance lasting four years was carried out to detect cases among recovered pneumonia. The protocol included the systematic detection of urinary L. pneumophila antigen (EIA), search of the microorganism in respiratory secretions, and seroconversion (IFA) as confirmation test. Cases were included, after obtaining informed consensus, in a case-control study to evaluate environmental, clinical and personal characteristics associated with the disease. As controls, both healthy subjects and patients affected by other pneumonia were recruited. Results: We detected 189 cases on 6,032 examined pneumonia (3.13%), 174 were community and 15 nosocomial-acquired. Prevalence varied between 1.5 and 6.1% according to the surveyed hospital. One hundred and twenty-six patients and 142 controls entered in the case-control design. Pre-existing immune-pathologies were associated with the disease, whereas higher smoking and co-morbidity were risk factors of all pneumonia. A significant decrease in CD16 (natural killer) cell number was found in patients compared with both control groups. Furthermore, significant alterations in iron metabolism and serum trace elements were found. Polymorphisms of the chemokines receptors genes (ccr5 and ccr2) were also evaluated. Conclusions: Our active clinical surveillance scheme was able to identify 189 cases between 2001 and 2004, contributing to increase reports in Italy, where about 600 cases for year are notified. The rate of infection in recovered pneumonia was about 3%, confirming results of other similar surveys. The preliminary results of the case-control study show that cases have peculiar, although not sufficiently studied, alterations in both immune and biochemical parameters, which deserve further investigations.

A cross-sectional multicenter survey of Italian hotels was conducted to investigate Legionella spp. contamination of hot water. Chemical parameters (hardness, free chlorine concentration, and trace element concentrations), water systems, and building characteristics were evaluated to study risk factors for colonization. The hot water systems of Italian hotels were strongly colonized by Legionella ; 75% of the buildings examined and 60% of the water samples were contaminated, mainly at levels of ≥10 3 CFU liter −1 , and Legionella pneumophila was the most frequently isolated species (87%). L. pneumophila serogroup 1 was isolated from 45.8% of the contaminated sites and from 32.5% of the hotels examined. When a multivariate logistic model was used, only hotel age was associated with contamination, but the risk factors differed depending on the contaminating species and serogroup. Soft water with higher chlorine levels and higher temperatures were associated with L. pneumophila serogroup 1 colonization, whereas the opposite was observed for serogroups 2 to 14. In conclusion, Italian hotels, particularly those located in old buildings, represent a major source of risk for Legionnaires' disease due to the high frequency of Legionella contamination, high germ concentration, and major L. pneumophila serogroup 1 colonization. The possible role of chlorine in favoring the survival of Legionella species is discussed.