[Assessment of occupational risk of Legionella spp. infection among dental health-care personnel]

Various authors have reported the presence of Legionella spp. in dental unit waterlines with prevalence rates reaching, in some cases, 69.7% In order to evaluate the association between occupational exposure to Legionella and risk of infection, anti-Legionella spp. antibodies were measured in 88 dental assistants, 44 of which exposed and 44 not exposed to dental environments. Antibody levels > 1:128 were considered positive for infection. Relative risk was found to be 3.5 (p<0.01). These results confirm the hypothesis that workers in dental health-care settings are at occupational risk for Legionella infection. It is essential, therefore, that surveillance of microbiological quality of dental waterlines be implemented and appropriate disinfection procedures performed where necessary.