Legionnaires\u27 Disease: A Practical Approach to Diagnostics and Treatment

Legionele redovito koloniziraju različite vodoopskrbne sustave i uređaje, a čovjek se infi cira inhalacijom kontaminiranog vodenog aerosola. Od legionarske bolesti obolijevaju sve dobne skupine, a češće stariji ljudi, poglavito oni s kroničnim bolestima srca, pluća i bubrega, no posebno su ugroženi bolesnici s oslabljenim imunosnim sustavom. Legionela je odgovorna za 2 do 15% pneumonija u općoj populaciji. Nema pouzdanih kliničkih, laboratorijskih ili radioloških pokazatelja kojima se sa sigurnošću može razlikovati legionarska bolest od drugih pneumonija, pa kliničku sumnju uvijek treba potvrditi specifi čnim laboratorijskim testovima (kultura, otkrivanje antigena u respiratornom sekretu ili u mokraći, serološki testovi, molekularna dijagnostika). U kliničkom je radu osobito praktičan i pouzdan brzi test za otkrivanje antigena legionele u urinu. U liječenju legionarske bolesti najvažnije je što prije primijeniti odgovarajući antibiotik. Međutim, L. pneumophila, kao i drugi uzročnici pneumonija, u svakodnevnom se kliničkom radu malokad dijagnosticira na početku bolesti, kada se započinje antimikrobno liječenje. Budući da su legionele relativno česti uzročnici upale pluća, razumno je i racionalno pri empirijskom liječenju pneumonija, posebno atipičnih, upotrijebiti antibiotik koji je učinkovit i protiv legionela. Novi makrolidi, posebno azitromicin, in vitro i u eksperimentalnom modelu imaju bolju aktivnost od eritromicina koji se tradicionalno preporučuje u liječenju legionarske bolesti. U liječenju se uspješno upotrebljavaju i fl uorokinoloni te doksiciklin i rifampicin. Zakašnjenje u primjeni učinkovitog antibiotika rezultira lošom prognozom. Zato svi bolesnici s težom kliničkom slikom pneumonije ili težim pratećim kroničnim bolestima i oslabljenim imunosnim sustavom u inicijalnom empirijskom liječenju zahtijevaju antibiotik s dobrim učinkom na legionelu. Naše kliničko iskustvo pokazuje da je pravodobno započeto liječenje legionarske bolesti azitromicinom klinički uspješno i ključno za ishod bolesti.Legionellae regularly colonise water supply systems and devices, and people are infected through the inhalation of a contaminated water aerosol. Legionnaires\u27 disease affects all age groups and more often elderly people, particularly those with chronic cardiac, pulmonary and renal diseases. Immunocompromised patients are at especially high risk. Legionella is responsible for 2 to 15% of pneumonias in the general population. There are no reliable clinical, laboratory or radiological indicators that could with certainty differentiate legionnaires\u27 disease from other pneumonias. Consequently, clinical doubts should be always confi rmed with special laboratory tests (culture, detection of antigen in respiratory secretion or urine, serologic tests, molecular diagnostics). Legionella urinary antigen test is especially convenient and reliable in clinical practice. The appropriate antibiotic should be administered in the treatment of legionnaires\u27 disease as early as possible. However, L. pneumophila, as many other causes of pneumonia, is rarely diagnosed at the onset of the disease when the antimicrobial treatment is initiated. Since legionellae have been relatively frequently reported as causative agents of pneumonia, it is advisable and rational to use legionellaeffi cient antibiotics in the empirical treatment of pneumonia, and particularly of atypical pneumonias. New macrolides, and especially azithromycin, exhibit better activity in vitro and in the experimental model than erythromycin, which is traditionally recommended for the treatment of legionnaires\u27 disease. Fluoroquinolones, doxycycline and rifampicin have been also successfully used. A delayed administration of an effi cient antibiotic results in a bad prognosis. Therefore, all patients with a more severe clinical picture or severe accompanying chronic diseases and compromised immunity require an antibiotic effi cient against legionella during the onset of the treatment. Our clinical experience shows that a timely treatment of legionella with azithromycin has been successful and crucial for the outcome of the disease