Radiographic appearance of nosocomial legionnaires' disease after erythromycin treatment.

Abstract

Radiographic features of 71 patients (48 men, 23 women) with nosocomial Legionella pneumophila pneumonia were assessed and compared with those of other nosocomial series of L pneumophila pneumonia. Sixteen patients were assessed retrospectively and 55 prospectively. Chest radiographs were assessed at the onset of the illness, 10 days later, and at 3 months. Erythromycin was given to 67 patients at the time of the diagnosis and to the remaining four at a later stage. Forty eight patients were over the age of 60. On the initial chest radiograph 53 of the 71 patients had unilateral shadowing (23 of them in the right lung); 35 had unilobar shadowing and the remaining 36 had more than one affected lobe. Pleural effusion was present in 24 cases and cavitation in 2. One patient had evidence of a pericardial effusion. At 10 days 21 patients had evidence of radiographic progression (14 ipsilateral), but 28 had improved. At 3 months 36 patients had an abnormal radiograph, 30 showing residual scarring, 15 loss of volume, six pleural shadows and two cavitation. Our series shows a lesser incidence of unilateral shadowing and pleural effusion than other nosocomial series and a lesser tendency to progression, but more patients had radiographic abnormalities at long term follow up.

Evaluation of Non-Resolving and Progressive Pneumonia

“…The evolution of the symptoms of CAP by Legionella spp. is slower than that with other typical microorganisms, and may even lead to progressive pneumonia, triggering severe respiratory insufficiency and radiographic progression [20]. The radiographic evolution of this type of pneumonia may show worsening in condensation and dissemination to the contralateral lung in one third of the patients [21], particularly in mixed infection by more than one species of Legionella; normalization of the images within 4 weeks is only achieved in 12o/o, and in up to 40o/o residual lesions may be present at three months [11].…”

Can Legionnaires Disease Be Diagnosed by Clinical Criteria?

“…The tendency for radiographic abnormalities to progress while the patient is receiving antibiotic therapy has been widely noted, and earlier studies [12][13][14][15] have suggested that such progression is more frequent in patients with Legionnaires disease than in those with other types of pneumonia. In a study 16 of hospital-acquired Legionnaires disease, 29% of patients showed progression of a unilateral infiltrate that spread to other lobes despite receiving erythromycin. Similarly, in a study 17 of community-acquired Legionnaires disease, 65% of patients had a worsening of radiologic findings in the first week.…”

Community-acquired pneumonia by Legionella pneumophila serogroups 1–6 in Brazil

“…8,33,34 Patient 1 presented a progression of the radiological lesions during specific antibiotics to Legionella despite clinical improvement, as reported. 2,28,35,36 Patient 1 and 2 worsened initially on beta-lactams, a classical finding; 2 while patient 3 improved and got cured only on beta-lactam antibiotics, like other recently reported patients, 28,35,37 adding to the evidences that in some cases Legionella pneumonia may be a self-limited disease which gets cured despite non-specific antibiotic therapy.…”