Legionella pneumophila is an intracellular pathogen which lives in the water environment. It invades human bodies through water aerosol inhalation, rarely through aspiration. It spreads out in the organism by blood, lymphatic system or through continuity. There are two forms of Legionella infections legionnaires disease and Pontiac fever. Extrapulmonary forms occur very rarely. Complications may occur as atelectasis, pleural effusion, adhesions, lung abscesses, pleural empyema, bronchopulmonary fistulas and in consequence even multiorgan failure. In the diagnosis of a Legionella infection isolation and microbial cultures, genetic methods and serological tests are used. In the treatment macrolides and in severe form fluorochinolons are efficient. Trimethoprim + sulfamethoxazole is an alternative treatment. In the article 14 years old boy case was presented. The child was admitted to hospital due to high fever, weakness, vomiting, headache and abdominal pain. Series of tests were performed to explain the cause of the ailments. Series of tests were performed to explain the cause of his complaints. High level of inflammation markers as well as leukopenia and thrombocytopenia were detected. Next there was a sudden onset of severe cough and a maculopapular rash. In additional tests involvement of the cardiovascular system was suspected. Due to suspected atypical infection macrolide was applied. The condition improvement and resolution of symptoms were achieved. Later the result for Legionella pneumophila infection was received and it indicated the possibility of this aetiology.

Legionella, legionellosis, legionnaires disease, Pontiac fever, diagnostics of legionellosis