Legionnaires' Disease in Patients with Associated Serious Disease

Abstract

Of nine patients with Legionnaires' disease, seven were receiving corticosteroids, and all nine had serious underlying diseases. Direct immunofluorescent examination of respiratory secretions, including sputum and transtracheal aspirates, showed the Legionnaires' disease (LD) bacterium in five of seven patients who seroconverted and in a sixth patient with a single elevated titer to the LD bacterium. All nine patients received erythromycin therapy, and five survived. Two patients showed persistence of their infection after receiving 2 weeks of erythromycin therapy, and two patients developed pulmonary abscesses. These cases of Legionnaires' disease show the occurrence of pulmonary abscesses, the possibility of relapse after giving only 2 weeks of erythromycin therapy, and the utility of direct immunofluorescence for early diagnosis.

Inhibitory and bactericidal activities of levofloxacin, ofloxacin, erythromycin, and rifampin used singly and in combination against Legionella pneumophila

“…It is known from previous in vitro studies with and without the inclusion of macrophages that the effect of erythromycin on L. pneumophila is an inhibitory one (2,18,21,24,25,31,38). In vivo comparative drug studies of the doses and lengths of therapy needed in patients with different primary diseases are lacking (8,16,23,(28)(29)(30). Therefore, the possible use of different cell-penetrating drugs other than macrolides, i.e., rifampin or fluoroquinolones, has been investigated.…”

“…However, this effect was observed only at 2.0 times the MIC of either drug. Erythromycin and ofloxacin at similar concentrations had inhibitory effects, with evidence of regrowth of the organism at 72 h. Because of the frequent addition of rifampin to patients seriously ill with infections caused by L. pneumophila, our time-kill curve studies included fluoroquinolone or erythromycin combinations with The mortality rate among patients with L. pneumophila infections continues to be high, especially in bacteremic, immunocompromised, and intubated patients (8,16,23,29). It is known from previous in vitro studies with and without the inclusion of macrophages that the effect of erythromycin on L. pneumophila is an inhibitory one (2,18,21,24,25,31,38).…”

“…It has been demonstrated that while erythromycin, clindamycin, newer macrolides, and selected other antimicrobial agents are primarily inhibitory in their in vitro activities against Legionella pneumophila, fluoroquinolones and rifampin exhibit a rapid inhibitory and bactericidal activities which are concentration dependent (1-6, 9-12, 15, 17-22, 24-26, 31-35, 39). To maximize clinical efficacy and minimize the selection of resistant mutants, rifampin is frequently added to the therapy with erythromycin, especially for the treatment of more severe cases of Legionnaires' disease (8,16,23,29). Few in vitro studies have compared the inhibitory and bactericidal activities of fluoroquinolones with the addition of rifampin (2,17,27,39).…”

“…The treatment of Legionnaires' disease to date includes erythromycin as the first-choice antimicrobial agent (8,16,23,29). Other drugs include azithromycin, clarithromycin, fluoroquinolones, doxycycline, or trimethoprim-sulfamethoxazole.…”

Legionnaires disease: historical perspective

“…Initially, viral and toxic etiologies were sought, because of the clinical resemblance of the pneumonia to severe influenza. Although clinical features suggestive of Legionella infection, such as prominence of gastrointestinal and cerebral symptoms, have been described (121,156,182,231), some investigators have found it difficult to differentiate between pneumonia caused by Legionella spp. and that caused by other bacteria (186,222,279).…”