[Legionella spp: An update]. / Actualités sur les infections à Legionella.

Legionella-related disease is caused by an intracellular bacteria mainly living in water. Contamination results from inhalation of Legionella sp containing aerosolized water. Main risk factors are tobacco, immunodeficiency, and advanced age. Antigenuria is the cornerstone of the diagnosis. Immunocompromised patients, more commonly infected with non pneumophilaLegionella, present negative antigenuria, and culture and PCR are essential for the diagnosis. Legionnaires' disease may be severe, especially in elderly and/or immunocompromised patients. Mortality rate varies from 10 % in the general population to 50 % in intensive care. Treatment is based on macrolides or fluoroquinolones. Antibiotic resistance is very rare.

A case report of Legionella and Mycoplasma pneumonia: Co-incidence or co-infection?

RATIONALE: Concurrent or sequential coinfections of Legionella pneumophila and Mycoplasma pneumoniae have been reported in the past though infrequently. Distinguishing a true co-infection from cross reactivity is often challenging as the diagnosis is mostly dependent on serological testing. PATIENT CONCERNS: A 77-year-old male presented with worsening dyspnea, cough with yellow sputum, diarrhea and fever of 2-days duration. Patient had history of chronic obstructive pulmonary disease (COPD) on home oxygen, bronchiectasis, rheumatoid arthritis (on methotrexate and leflunomide), treated pulmonary tuberculosis and 30-pack-year smoking. Chest X-ray showed bilateral interstitial changes with left lower lobe infiltrate. On day 5, his urine antigen for L pneumophila serogroup 1 was reported positive. The following day his serum M pneumoniae IgM antibody titers were reported elevated at 6647 U/mL. Patient was started on antibiotics and placed on non-invasive positive pressure ventilation. DIAGNOSIS: The patient was diagnosed with possible Legionella and Mycoplasma co-infection. OUTCOMES: Sputum Mycoplasma polymerase chain reaction (PCR) and serum cold agglutinins were obtained on day 6 and later reported negative. He was treated with azithromycin for 10 days with clinical improvement. LESSONS: Serological testing alone is an indirect measure with poor sensitivity and specificity and has its own limitations. Urine antigen detection confirms L pneumophila serogroup 1 infection in a patient with suggestive symptoms. However, diagnosis of M pneumonia should be based on combination of tests including serology and PCR to confirm true co-infection.

[Extracorporeal life support for Legionella pneumonia]. / Extracorporele life support bij Legionella-pneumonie.

BACKGROUND: Legionella species cause 5% of all community acquired pneumonias. However, Legionella pneumonia results relatively often in admission to the intensive care unit (ICU). A significant complication is the development of acute respiratory distress syndrome (ARDS). The ICU mortality rate for Legionella pneumonia is > 30% with conventional treatments. CASE DESCRIPTION: A 64-year-old male was admitted to the ICU with respiratory failure due to Legionella pneumonia complicated by ARDS. Despite maximum conventional therapy being given, including lung-protective invasive mechanical ventilation and prone positioning, progressive hypoxaemia persisted. In collaboration with an extracorporeal life support (ECLS) centre, venovenous ECLS was initiated. Pulmonary function recovered and the patient was successfully weaned from VV-ECLS after 17 days. After three months of hospitalisation and rehabilitation, the patient was discharged home and able to perform his activities of daily living without assistance. CONCLUSION: Legionella pneumonia relatively frequently results in ICU admission, and carries a high mortality with conventional treatments. ECLS may offer a solution if conventional therapies are not sufficiently effective.

Legionella Infection in Pregnancy: The Forgotten Pathogen in Septic Shock.

BACKGROUND: Of eight cases of Legionella infection in pregnancy reported over 35 years, there was one case of maternal septic shock with poor outcome, one recovery with good outcome, and six with poor outcome. CASE: A 30-year-old woman, gravida 2 para 1, at 28 weeks of gestation presented with a high fever, cough, nausea, and vomiting. She deteriorated despite treatment for presumed urosepsis, was transferred to the intensive care unit, and remained intubated for 10 days receiving cardiovascular support, antivirals, antifungals, and multiple wide-spectrum antibiotics. Legionella infection antigen testing was performed on hospital day 1 and returned as positive. Azithromycin, started before the testing results became available, was continued for 14 days. The patient recovered, and the pregnancy progressed uneventfully to term. CONCLUSION: Legionella infection should be considered with maternal deterioration despite broad-spectrum antibiotic coverage. A favorable outcome is possible with early diagnosis and treatment.

Extracorporeal membrane oxygenation and severe acute respiratory distress secondary to Legionella: 10 year experience.

Legionella-associated respiratory failure has a high mortality, despite modern ventilation modalities. Extracorporeal membrane oxygenation (ECMO) is used to achieve gas exchange independent of pulmonary function in patients with severe respiratory failure. This was a retrospective review of the management and outcome of patients with Legionella-associated respiratory failure treated with ECMO support in a large ECMO center over the past 10 years. A retrospective review of patients with confirmed Legionella-associated severe respiratory failure managed with ECMO support at a single center. Between 2000 and 2010, 19 patients with severe respiratory failure caused by Legionella were managed with ECMO after failure to respond to conventional intensive care management. Median PaO2/FiO2 ratio was 66 and median pCO2 was 60 torr. Sixteen patients (84%) survived to hospital discharge. Extracorporeal membrane oxygenation should be considered in patients with Legionella-associated respiratory failure, who have failed conventional ventilation.

Parainfectious meningo-encephalo-radiculo-myelitis (cat scratch disease, Lyme borreliosis, brucellosis, botulism, legionellosis, pertussis, mycoplasma).

Parainfectious disorders of the nervous system encompass those meningo-encephalo-radiculomyelitic conditions that are temporally associated with a systemic infection, antigenic stimuli, or toxin exposure, in the absence of evidence of direct neuronal infection or invasion of the central nervous system (CNS) or peripheral nervous system (PNS). Pathogenetic mechanisms can be due to immune-mediated processes (such as bystander activation, molecular mimicy) or the inciting insult can be due to toxic factors, as in the case of botulism. A myriad of clinical manifestations can occur including headache, seizures, and mental status changes, ranging from mood and behavioral disturbances to varying levels of alteration in consciousness. Focal neurological deficits can include aphasia, hemiparesis, or paraparesis. The PNS can also be affected leading to cranial nerve involvement, focal or multifocal neuropathies, and dysfunction of the autonomic nervous system. Diagnosis is based not only on the history, examination, laboratory, and neuroimaging data but also on epidemiological factors. The parainfectious disorders covered in this review are cat scratch disease, Lyme borreliosis, legionellosis, brucellosis, botulism, pertussis, and mycoplasma. Each is associated with a distinct organism, has both systemic and neurological manifestations, and has a different epidemiological profile.

[Extracorporeal membrane oxygenation in Legionella pneumonia]. / Ekstrakorporal oxygenering ved legionellapneumoni.

We present a case report with a 49-year-old woman with legionella pneumonia and fulminant respiratory failure. Despite maximal conventional respirator treatment with positive pressure ventilation, 100% oxygen and pharmacological treatment in an intensive care unit, further deterioration with hypoxemia and multi-organ failure occurred. The patient was referred to ECMO as a last option of treatment. Eight days of treatment with ECMO was completed without any complications except critical illness polyneuropathia (CIP) for which she was treated for an additional four weeks in the ICU.

Deadly viral syndrome mimics.

Upper respiratory tract infections (ie, "the common cold") have several hundred causes, the most common of which include rhino-virus, coronavirus, and respiratory syncytial virus. The clinical presentation varies with symptoms. Every emergency department, no matter what the demographics, cares for patients with this constellation of symptoms. Emergency physicians examine, diagnose, and treat these disorders frequently. With increasing burdens being placed on emergency physicians, it is possible to assume a diagnosis of upper respiratory tract infection without generating a complete differential diagnosis. The challenge is to identify and recognize the distinctions between an innocuous upper respiratory tract infection and a life-threatening disease "mimic" or entities. This article discusses some of these life-threatening mimics.

[Diagnosis of legionellosis]. / Quand penser à une légionellose?

The majority of legionellosis are caused by Legionella pneumophila, especially serogroup 1, the only diagnosed by Legionella urinary antigen test. The diagnosis of other serogroups and other Legionella species is based on culture and seroconversion. Sever cases are more frequently observed in immunocompromised patients and in nosocomial pneumonias. Each case must lead to look for the source of contamination, to detect other potential patients and permit environmental measures. Clinically and radiographically, the pneumonia is non specific except if suggestive gastro-enteric or neurologic symptoms are present. The diagnosis could be suspected in case of relative bradypnia or beta-lactamin resistance.

[The epidemiology and clinical features of Legionella pneumonia (LP) in patients older than 60 years old who were hospitalized with pneumonia in northern Israel].

BACKGROUND: Risk factors associated with LP are frequent in patients older than 60 years old who are hospitalized with pneumonia. The aim of the study was to define the incidence, epidemiological and clinical features of LP in this age group in Northern Israel. STUDY DESIGN: The study was prospective and conducted for one year during the period 1.6.1999-31.5.2000. All patients older than 60 years who were hospitalized with community-acquired or nosocomial pneumonia were tested for legionella infection by the urine antigen test (which identifies Legionella pneumophila type I and 14 other Legionella serotype antigens). Data was obtained from each patient regarding risk factors and clinical feature of the disease. The data of patients with LP was compared on a 1:2 ratio to data obtained from a control group of patients with non LP according to age, sex, and week of admission. RESULTS: During the study period 202 patients and 38 patients were hospitalized with community-acquired or nosocomial pneumonia respectively. Overall, 8/240 patients (3.3%) were found to suffer from LP. All patients with LP had community-acquired pneumonia with an incidence of 8/202 (4%). Six of the 8 patients (75%) with LP were hospitalized during June-September. Significant clinical findings in patients with LP as compared to those in the control group, respectively, were: severity score, history of smoking, mental status alteration, respiration rate over 30/minute, respiratory acidosis, hypoxia, and need for mechanical ventilation (P < 0.05 in all). All patients with LP were treated with macrolides, however the death rate was 50% vs 0% in the control group (p < 0.001). CONCLUSIONS: In northern Israel, LP is infrequent among patients older than 60 years hospitalized with pneumonia. The disease occurs mostly during the summer in patients with community acquired pneumonia. Patients with LP had unique and more severe clinical features and the death rate was very high inspite of appropriate therapy.

Bilateral pleuritis caused by Legionella micdadei.

A 58-year-old woman was hospitalized because of progressive respiratory distress. She had a history of myasthenia gravis and invasive thymoma. After thymectomy, she had been administered oral prednisolone and intrathoracic anti-cancer drugs postoperatively. Her chest radiograph revealed bilateral pleural effusions. Legionella micdadei (L. micdadei) was isolated from the pleural effusions, and she was diagnosed as pleuritis caused by L. micdadei. She died despite intensive therapy with mechanical ventilation, drainage tube in the chest and intravenous erythromycin. Although only two cases of Legionellosis caused by L. micdadei have been reported in Japan, clinicians should be aware of L. micdadei as one of the candidates for infection in immunosuppressed hosts.

Epidemiological typing of Legionella pneumophila with ribotyping. Report of two clinical cases.

The ribotyping method, adapted to the strains of Legionella pneumophila in our possession, was tested in two separate cases of legionellosis and in the associated finding of Legionella pneumophila in the water, from different sources, with which these patients had come into contact. Determination of the serogroup enabled us to carry out a preliminary analysis of the strains, which was then confirmed by application of the ribotyping procedure: the ribosomal profile of the strains found in the two patients correspond to that of the strains isolated from the water with which they had come into contact. These results provide important information concerning the probable sources of infection involved in these two cases of Legionnaires' disease. We consider ribotyping to be a very useful tool, which is easy and simple to perform and is applicable to the Legionella genus as the method of choice for epidemiological studies.

[Legionellosis]. / Le legionellosi.

In the above review, the authors intended to stress the epidemiologic importance of legionellosis which has become a frequent cause of respiratory pathology in the short time since its first appearance (1976), reaching a for from negligible proportion among respiratory disorders (2-8% of acute bronchopulmonary diseases) and a considerable death rate (10-40%). Clinical and diagnostic as well as therapeutic aspects and especially prophylaxis all discussed, the latter concerning above all the environment and adequate maintenance of heating and air-conditioning equipment in community centers, and particularly in hospitals and hotels.