Legionella pneumophila antibodies in serum samples from medical and dental personnel: a seroepidemiological survey

Abstract

Variety of health technologies applied in medical and dental practice are associated with formation of fine water droplets/aerosols. This presents a potential risk of both the patients and the personnel acquiring Legionnaires' disease. The aim of this study was to assess the presence of Legionella antibodies in the personnel (medical and dental) and a control group. The serum antibody index (Ab index) to L. pneumophila Sg1-6 (IgG + IgM) was determined using enzyme-linked immunosorbent assay. L. pneumophila Sg 1-6 antibodies (Ab index > 5) were found in 27/66 (40.91%) of the personnel vs. 7/90 (7.78%) of the control subjects (χ2 = 24.55, p < 0.0001). There was no statistically significant difference in the seropositivity levels in the groups in terms of sex, concomitant chronic diseases, intake of medications affecting the immune response, smoking and history of pneumonia. Association was observed with the professional categories of the personnel (χ2 = 6.836, df = 2, p < 0.05): more than 50% of the physicians were seropositive for L. pneumophila. The logistic regression analysis proved the role of seropositivity associated factors such as age, use of protective equipment and workplace (building with proven presence of L. pneumophila in the water system). The seroprevalence rate of Legionella antibodies in the personnel can be associated with occupational risk exposure, especially in the absence of systematic and regular use of protective equipment during work and the lack of an established system for regular monitoring and preventive maintenance of the water systems in the healthcare facilities.