Title : Legionella pneumophila pneumonia: An underdiagnosed disease, but with a high impact
Abstract:
Legionella pneumophila is an aerobe, non-sporulated, facultative intracellular, mobile, gram-negative bacillus. It’s the cause of pneumonia in immunosuppressed patients, usually in a severe form which can expand to multiple lobes, or occasionally, a self-limited mild form, mimicking a flu, called Pontiac fever. Legionella is an airborne microorganism, its main way of spreading being through contaminated water mists or droplets. It persists inside aquatic systems such as plumbing networks, air conditioners and can replicate using hosts like protozoa or amoebae. Medical studies lack of a single global report on Legionella’s annual death tool, but in 2021 ECDS mentioned a total of 704 fatalities in EU/EEA territory. The clinical aspects of “Legionnaires’ disease” include fever, dyspnea, nonproductive cough, accompanied by gastrointestinal symptoms. The identification method used in our clinic was urinary antigen test.
We’ve conducted a retrospective study on a lot of 39 patients hospitalized in our clinic between 2023-2025. The exclusion criterium was the age, patients under the age of 18 being removed from the study because we’ve been monitoring adults’ department only. The aspects we’ve checked were age, sex, obesity or smoking background, total days of care in our clinic and mortality. We’ve made several comparisons between our whole study group and those suffering from obesity or smokers.
The limits of our study were the size of our study lot (only 39 patients) and the tendency of underreporting this germ because of diagnostic difficulties.
Our data confirms the fact that Legionella is continuously threatening elderly population, highlighting the necessity of watchful supervision of water sources and high clinical vigilance while facing severe pneumonias with atypical evolution.
