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Query: UMLS:C0023241 (Legionella)
 6,990 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A cluster of five cases of Legionnaires' disease in renal transplant patients is described. They were treated with erythromycin and rifampicin, and all five survived. Two of them had rejected their grafts prior to their Legionella pneumonia; two rejected their transplants after reduction of immunosuppressive therapy to combat the infection. L pneumophila was present in the water distribution system of the hospital. Eradication measures included flushing the water pipes to the transplantation ward with hot and hyperchlorinated water, raising the warm water temperature to 60 degrees C, and installing ultraviolet (UV) irradiation units on the warm and cold water pipes to the ward. These measures were successful in that no new cases of legionellosis occurred after wards. L pneumophila could subsequently not be demonstrated by culture in plastic shower hoses supplied with UV-irradiated water. L pneumophila could be demonstrated by direct fluorescent antibody technique, but nonspecific reactions cannot be excluded. A higher prevalence of elevated L pneumophila antibody titers was observed in patients nursed for more than four weeks in the hospital than in patients with a shorter hospital stay, in hospital staff members, or in the general population. It seems that, with appropriate control measures, transplantation activities need not be discontinued in the presence of a minor cluster of Legionnaires' disease in renal transplant patients.
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PMID:Nosocomial Legionnaires' disease following renal transplantation. 329 50

In 1981, sixteen cases of nosocomial legionellosis occurred among 456 patients admitted to a new hematology-oncology unit (35 per 1000 admissions). Monoclonal antibody typing and restriction endonuclease plasmid analysis identified a unique strain (09,04) of Legionella pneumophila serogroup 1 isolated from both patients and water outlets. Continuous hyperchlorination of the hot and cold water began in January 1982, and chlorine levels of 3 to 5 mg/L have been maintained most recently. Water samples have been consistently negative for Legionella for more than five years. Four sporadic cases of nosocomial legionellosis have occurred in the hematology-oncology unit during the same period (one per 1000 admissions) associated with a different strain of L pneumophila serogroup 1 (09,00). The environmental reservoir(s) of L pneumophila serogroup 1 in these cases has not been identified. Levels of trihalomethanes (potential carcinogens) were high (greater than 100 micrograms/L) when chlorine levels of hot water exceeded 4 mg/L. Some corrosion damage to the water distribution system has occurred: the average number of leaks per month increased steadily from zero in 1982 to 5.2 in 1986. The chlorinator installation costs were +75,800, and annual operation expenses were +12,500. Continuous hyperchlorination is a promising but still experimental technique for control of nosocomial legionellosis. In our experience, epidemic disease has been controlled, but sporadic cases have continued to occur.
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PMID:Legionnaires' disease associated with a hospital water system. A five-year progress report on continuous hyperchlorination. 335 31

The present study was an in vitro attempt to define the effector mechanisms against the intracellular bacterium Legionella pneumophila. Monocytes from human peripheral blood leukocytes (PBL) were infected in vitro with L. pneumophila and cultured for 2 days to allow intracellular replication of the bacterium. Cells were then labeled with 51Cr and used as targets in a 4-h 51Cr-release assay. We report here that autologous nonadherent PBL effectively lysed infected monocytes, and this activity was enhanced when the effector cells were precultured with IL 2 for 2 days. The IL 2-activated killer cells were also cytolytic against uninfected cultured monocytes, but cytotoxicity was higher against Legionella-infected target cells in a dose-dependent manner. The effector cells were located in Percoll density fractions that were enriched for large granular lymphocytes. The phenotype of the effector cell activated by IL 2 was determined to be OKM1+, OKT11+, partially Leu-11+, and negative for Leu-M1, OKT4, OKT8, and Leu-7, indicating that it is neither a T cell nor a monocyte, and is possibly and NK subset that is Leu-11+ and Leu-7-. Cold target inhibition studies indicated that a similar recognition structure is shared by both infected and uninfected monocytes, but differs from that on K562 tumor target cells. Thus, in addition to tumor surveillance and controlling viral infections, killer cells can be activated to provide protection against intracellular bacterial infections.
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PMID:Cytolytic activity of human peripheral blood leukocytes against Legionella pneumophila-infected monocytes: characterization of the effector cell and augmentation by interleukin 2. 349 84

Cigarette smoking exerts deleterious effects not only on the respiratory tract, but also on the lung's parenchyma. The FEV is reduced in heavy chronic smokers. Persistent smoking has an unfavourable influence on mucociliary activity. According to the results of recent research almost 8 million people in the U.S. were suffering from chronic bronchitis in 1981. There is a direct correlation between the number of cigarettes smoked, over what period of time, and the incidence of chronic bronchitis. In studies with patients suffering from exacerbations of chronic bronchitis the most common bacterial pathogens found were Haemophilus influenzae, Streptococcus pneumoniae and Branhamella catarrhalis. Mycoplasma pneumoniae and certain viruses are counted amongst the non-bacterial pathogens. Antibiotics should be effective against such possible pathogens. The resistance of H. influenzae to ampicillin/amoxicillin is currently observed in at least 12% of cases, whilst H. influenzae is regularly observed to be resistant to erythromycin. Cefaclor, trimethoprim/sulphamethoxazole and amoxicillin/clavulanic acid offer satisfactory forms of treatment. Pneumonia caused by S. pneumoniae, H. influenzae, B. catarrhalis and Legionella pneumophila is often seen in smokers and patients with COLD. Haemocultures should be prepared for all hospitalized patients. Penicillin G and/or V is the agent of choice. Cefaclor or trimethoprim/sulphamethoxazole can be given to counter beta-lactamase producing H. influenzae whilst cefaclor, erythromycin, tetracycline or trimethoprim/sulphamethoxazole are used for the treatment of B. catarrhalis infections. In Legionella infections erythromycin is the preferred treatment. A combination of erythromycin and cefamandole or ceftriaxone is indicated for empirical management. Patients with COLD should be immunised with pneumococcus and influenza vaccines.
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PMID:[Smoking and lower respiratory tract infection]. 361 Mar 32

We conducted a prospective environmental study for Legionella pneumophila in 15 hospitals in Pennsylvania. Hot water tanks, cold water sites, faucets, and showerheads were surveyed four times over a one-year period. Sixty percent (9/15) of hospitals surveyed were contaminated with L pneumophila. Although contamination could not be linked to a specific municipal water supplier, most of the contaminated supplies came from rivers. Parameters found to be significantly associated with contamination included elevated hot water temperature, vertical configuration of the hot water tank, older tanks, and elevated calcium and magnesium concentrations of the water (P less than 0.05). This study suggests that L pneumophila contamination could be predicted based on design of the distribution system, as well as physicochemical characteristics of the water.
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PMID:Determinants of Legionella pneumophila contamination of water distribution systems: 15-hospital prospective study. 365 30

A protocol for sampling environmental sites was developed and used to identify possible sources of Legionella species in support of epidemiologic investigations at two hospitals. In hospital A, legionellae were isolated from 43 of 106 (40%) different sites. Three separate Legionella pneumophila serotypes and a previously unrecognized species were present in different combinations in the positive samples. Two of five cooling towers contained the same L. pneumophila serogroup 1 monoclonal type (1,2,4,5) as was isolated from patients. The same monoclonal type was also isolated from make-up water for the two cooling towers, a hot water tank, water separators in four main air compressor systems for respiratory therapy, and cold and hot water faucets. In hospital B, 13 of 37 (38%) sample sites contained legionellae, all of which were L. pneumophila serogroup 1. The monoclonal type matching isolates from patients (1,2,4,5) was found at the highest concentration in a hot water tank, but it was also present at four other sample sites. Since legionellae not related to disease may be found in many of the sites sampled, an epidemiologic association with the probable source should be established before intervention methods, such as disinfection, are undertaken.
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PMID:Protocol for sampling environmental sites for legionellae. 366 1

In September and October 1981 six cases of pneumonia occurred among men working in a power station under construction. Three were identified as cases of legionella pneumonia and two others had serology suggestive of legionella infection. In a sample of 92 men from the site 10 had low levels of antibodies to legionella; a similar sample of men working on an adjacent site showed none with positive serology. In a case control study it was found that cases of pneumonia were more likely than controls to have worked on a part of the site where four small capacity cooling towers were located. Legionella pneumophila serogroup 1 was isolated from the water systems of these four towers but was not found in samples from any other cooling towers or hot or cold water outlets on the site. It would appear that there was airborne spread of the organism from these cooling water systems which had not received conventional treatment to inhibit corrosion and organic growth. This is the first outbreak of legionnaires' disease to be recorded in an industrial setting in the United Kingdom. No cases of legionella infection have occurred on the site since the introduction of control measures.
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PMID:Outbreak of legionnaires' disease from a cooling water system in a power station. 375 16

The presence of legionellae was investigated over 2 years in various types of water in Israel. Potable water, fish ponds, oxidation ponds and surface water were sampled on a monthly basis. Legionellae were not isolated during the cold months of the year (November to April), but were continually isolated during the rest of the year (May to October). Nineteen of 56 sources of water were found culture-positive for Legionella pneumophila serogroups 1, 2, 3, 4 and 6, L. bozemanii, L. israelensis and some nonspeciated Legionella. As irrigation water in Israel originates from the various types of water that we found to be culture-positive for Legionella, the public health implications of this finding were correlated with our previous seroepidemiological survey of irrigation workers.
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PMID:Seasonal distribution of legionellae isolated from various types of water in Israel. 379 47

The presence of amoebae and Legionella pneumophila in ground-water, drinking water supplies and whirlpools was investigated. Volumes of 10 to 1,000 ml were concentrated by membrane filtration. L. pneumophila was detected on buffered charcoal yeast extract (BCYE) agar, and amoebae by inverting filters on nonnutrient agar plates seeded with Escherichia coli that were incubated at 37 C for up to 12 days. In 65% of the samples positive for L. pneumophila amoebae were also detected. L. pneumophila and amoebae were detected together in 38% of warm drinking water samples. The highest isolation temperature for amoebae was 57 C, but fewer amoebae were detected above than below 50 C. In cold drinking water, amoebae were found in 88% of samples. The presence of L. pneumophila and amoebae in whirlpool waters (42%) presents a risk for man. Fresh environmental isolates of an Acanthamoeba species and L. pneumophila serogroup 4 were used for laboratory experiments. The amoebae supported intracellular multiplication of L. pneumophila in Chang's medium and autoclaved tap water, as shown by colony-forming unit (CFU) counts, direct fluorescent antibody test and Gimenez staining. Results confirmed that interaction between L. pneumophila and amoebae could occur in nature, and that the latter could act as hosts for legionellae and support their growth.
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PMID:Association between Legionella pneumophila and amoebae in water. 379 52

Although the mode of transmission of L. pneumophila is as yet unclear, the hot water distribution system has been shown to be the reservoir for Legionella within the hospital environment. In this report we identify a previously unrecognized reservoir for L. pneumophila within the hospital environment, ie, the cold water dispensers of hospital ice machines. The cold water dispensers of 14 ice machines were cultured monthly over a 1-year period. Positive cultures were obtained from 8 of 14 dispensers, yielding from 1 to 300 CFU/plate. We were able to link the positivity of these cold water sites to the incoming cold water supply by recovering L. pneumophila from the cold water storage tank, which is directly supplied by the incoming municipal water line. This was accomplished by a novel enrichment experiment designed to duplicate the conditions (temperature, sediment, stagnation, and continuous seeding) of the hot water system. Our data indicate that significant contamination of cold water outlets with L. pneumophila can occur. Although no epidemiologic link to disease was made, the fact that the primary source of a patient's drinking water is from the ice machines warrants further investigation of these water sources as possible reservoirs.
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PMID:Isolation of Legionella pneumophila from the cold water of hospital ice machines: implications for origin and transmission of the organism. 388 78


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