Legionnaires disease: results of 25-years of studying infections, problems and perspectives of research

The paper summarizes the results of 25-year study of Legionnaires' disease (Legionnaire's bacillus infection) in its epidemiology, diagnosis, and prevention, the taxonomy and biology of the causative organism. Emphasis is laid on the contribution of the Russian school of investigators in studying this problem. Despite the intensive efforts in investigating the infection and its causative organism, there are still many problems in predicting and preventing the epidemics of Legionnaires' disease, which annually occur in different countries of the world. Legionnaires' disease is a typical example of technogenic infections: active industrial and domestic uses of closed water circulating systems in industry and aerosol sources promote the spread of the infection caused by Legionnaire's bacillus and make its control in these systems. Despite the introduction of current immunological and molecular genetic methods, diagnosis is effective only for L. pneumophila, serogroup 1. The sensitivity and specificity of methods for diagnosis and identification for other 15 L. pneumophila serogroups and 41 species of L. bacilli are far from being perfect. L. bacilli are also a most popular object for studying the biochemical and genetic aspects of its intracellular parasitism.