Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023241 (Legionella)
 6,990 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Choosing appropriate antimicrobial therapy for patients with pneumonia requires knowledge of the etiologic agents seen in specific kinds of patients at specific times and places. For community-acquired pneumonia, there is an important difference in the agents seen in the normal and the compromised host. The normal host most often presents with viral, mycoplasmal, or pneumococcal pneumonia. The exact place of Chlamydia pneumoniae is still under study. A normal host who aspirates is at risk of anaerobic pneumonia. Normal hosts with influenza may acquire superinfection with Streptococcus pneumoniae, Haemophilus influenzae, or Staphylococcus aureus. Under specific epidemiologic conditions, community-acquired pneumonia may be due to Legionella species, Yersinia pestis, Francisella tularensis, Coxiella burnetii, Chlamydia psittaci, a mycotic agent, or tuberculosis. Patients with chronic bronchitis and emphysema are predisposed to H. influenzae, Moraxella catarrhalis, and S. pneumoniae infections. HIV-infected patients are likely to have Pneumocystis carinii pneumonia and pneumonia due to cytomegalovirus, S. pneumoniae, and H. influenzae. Patients with diabetes, nursing-home patients, hospitalized patients, immuno-compromised patients, and patients with recent antibiotic therapy are predisposed to pneumonia due to Gram-negative aerobic bacilli of enteric and environmental origin. Initial therapy should be directed at the likely organism or organisms based on hospital susceptibility surveillance. In the normal host with community-acquired pneumonia, the therapy will often be penicillin G or erythromycin. In the patient predisposed to Gram-negative pneumonia, a third-generation cephalosporin with or without an aminoglycoside is the usual choice.
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PMID:Pneumonia. Patient profiles, choice of empiric therapy, and the place of third-generation cephalosporins. 173 Jan 86

It has been reported that infections with Legionella pneumophila can lead to chronic inflammatory and fibrotic reactions in the human lung. To better characterize the nature of the residual abnormalities caused by this bacterium, we inoculated Syrian hamsters intratracheally with 10(8) serotype 1 L. pneumophila organisms and assessed histologic, functional, and biochemical changes at intervals up to 180 days. Acutely, L. pneumophila caused an intense alveolar macrophage (AM) and polymorphonuclear leukocyte (PMN) response within the lower air spaces, air-filled lungs were noncompliant, and there was an associated 25 to 50% increase in the lung content of collagen and elastin after 10 days. An inflammatory response, consisting principally of AM and centered around the terminal bronchioles, was still prominent in some infected lungs after 90 and 180 days, and the severity of the inflammation was correlated with a persistent restrictive defect in the elastic behavior of the lung. However, by histologic examination, fibrosis was not prominent, and the more representative abnormality was one of mild, diffuse air-space enlargement. Frank emphysematous changes were present focally in some lungs. In addition, an irregularly distributed lymphocytic infiltrate and goblet cell metaplasia were present in the larger bronchi of infected animals. We conclude that a single infection with L. pneumophila is capable of causing long-term inflammatory reactions in the lung, with morphologic features of both fibrosis and emphysema.
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PMID:Long-term pulmonary sequelae after Legionella pneumophila infection in the hamster. 293 77

As of April 30, 1980, 83 nosocomial cases of sporadic legionellosis had been reported to the Centers for Disease Control (CDC). In all 83 cases the patients had pneumonia; the median age of the patients was 56.5 years. All but one patient were hospitalized at the time of onset. Of 71 patients for whom the outcome is known, 22 (31 percent) died of causes directly attributed to their infection. Eleven patients had end-stage renal disease, 28 were receiving systemic immunosuppressive medications, 17 had cancer, 12 had chronic bronchitis or emphysema, 29 were smokers, and four had diabetes mellitus. Risks of acquiring nosocomial sporadic legionellosis for patients with these conditions relative to the general United States population = 340, 26, 11, 3.7, 1.9 and 1.3, respectively. These risk factors are similar to those identified for sporadic community-acquired legionellosis and for epidemic nosocomial legionellosis. Methods for preventing nosocomial legionellosis are not known, but comparing Legionella to other water-associated organisms which have been spread from medical devices to cause pneumonia may be fruitful.
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PMID:Sporadic and epidemic nosocomial legionellosis in the United States. Epidemiologic features. 721 4

As of 30 September 1979, 1005 confirmed cases of sporadic legionellosis caused by Legionella pneumophila serogroups 1 to 4 in U.S. residents had been reported to the Centers for Disease Control; 19% were fatal. All but 2% of the 1005 cases were associated with pneumonia documented by chest radiograph. About 75% of the cases occurred in June through October. The risk of acquiring sporadic legionellosis was increased among males and persons 50 years or older; persons with renal disease necessitating dialysis or transplantation, with chronic bronchitis or emphysema, with diabetes mellitus, and with cancer (10 selected sites or types); persons who smoke; and persons being treated with immunosuppressive drugs. Increasing age and chronic bronchitis or emphysema were associated with increased risk of death. The sensitivity of culturing L. pneumophila from specimens positive by direct immunofluorescence was estimated to be 45%. The distribution of serogroups 1, 2, 3, and 4 of L. pneumophila in 57 fresh, not previously examined direct fluorescent antibody-positive specimens was 84%, 11%, 4%, and 2%, respectively; all 26 strains isolated from these specimens were of one of these four serogroups.
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PMID:Sporadic legionellosis in the United States: the first thousand cases. 746 7

In January 2003, two cases of Legionnaires' disease associated with a ship's cruise were registered in the database of National Epidemiological Surveillance of Infectious Diseases. A 70-year-old male heavy smoker with mild emphysema contracted the disease during a cruise. Legionella pneumophila serogroup (sg) 5 was isolated from the patient's sputum and the ship's indoor spa. The isolate from the spa matched the patient's isolate by genotyping performed by pulsed-field gel electrophoresis (PFGE). The second case was in a 73-year-old female. During epidemiological investigation, a third case of Legionnaire's disease in a 71-year-old male was subsequently diagnosed among passengers on the same ship on the following cruise. Environmental investigation revealed that porous natural stones (Maifanshi) in the filters of the spas had harboured L. pneumophila, a phenomenon which has not been reported except in Japan. This is the first documented evidence of L. pneumophila sg 5 infection on a ship and of porous stones as a source of Legionella infection.
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PMID:Outbreak of Legionnaires' disease on a cruise ship linked to spa-bath filter stones contaminated with Legionella pneumophila serogroup 5. 1649 Jan 44