A community outbreak of Legionnaires' disease associated with a cooling tower in Vic and Gurb, Catalonia (Spain) in 2005.

We report the investigation of a community-acquired outbreak of Legionnaires' disease. An epidemiological, environmental, and meteorological investigation was undertaken. Fifty-five cases were reported in October and November 2005. The exposure occurred in a large area, with 12 cases (21.8%) located between 1,800 and 3,400 metres from the source. Water sample cultures showed that Legionella pneumophila serogroup 1 (Lp-1) was present in five cooling towers in two industrial locations in Gurb (plants A and B). Two Lp-1 strains were recovered from plants A and B, but only Lp-1 strains from plant A showed a pulsed-field gel electrophoresis (PFGE) profile identical to those obtained from three of the cases. Inspection of the cooling towers in plant A revealed inadequate maintenance. Weather conditions in October 2005, with mostly high temperatures and high humidity, together with the flat terrain could have been favouring factors. This study showed a community outbreak from a cooling tower as a common source in a large area. Climate and terrain could explain the dissemination of contaminated aerosols.

Evaluation of a Legionella urinary antigen enzyme immunoassay for rapid detection of Legionella pneumophila in water samples.

Despite advances in medium formulations and pretreatment techniques, recovery of Legionella from water samples can still be quite low, difficult and time consuming. The aim of this study was to evaluate the utility of a Legionella urinary antigen enzyme immunoassay (Bartels ELISA, Trinity Biotech, Ireland) for the detection of Legionella in water samples. Reference ATCC Legionella strains were used to spike water samples to a final concentration of 10(4)-10(5)cfu/ml. The lower detection limit of the test for all Legionella pneumophila serogroups was assessed by serial dilutions of spiked water samples. Legionella antigen was detected in all filtered samples except for those spiked with L. bozemanii and L. longbeachae. The lower detection limit for soluble L. pneumophila serogroup 1 antigen was 780cfu/ml. Bartels ELISA could be a useful method for antigen detection in water samples when a high recovery of L. pneumophila is suspected. The test could be used as a rapid screening method for the detection of Legionella in a large number of samples. However, the low sensitivity of the test requires to keep on performing conventional culture for isolation and for further studies on isolated bacteria.

An outbreak of Legionnaires' disease in an inner city district: importance of the first 24 hours in the investigation.

OBJECTIVE: To present the main results of the investigation of an outbreak of Legionnaire's disease that occurred in an inner city district of Barcelona between 15 October and 15 November 2000. METHODS: Epidemiological surveys of patients and environmental investigations were initiated on the day the first five cases were notified. Water samples and smears from cooling tower trays were taken for microbiological analysis. Maps of the distribution of cases and possible contamination foci were elaborated. Incidences were calculated for each census tract. RESULTS: A total of 54 patients related to the outbreak were identified, with a case fatality rate of 5.5%. Incidence rate in the area closest to the cooling tower (6.40/1000) was significantly higher than that of the rest of the neighbourhood (2.23/1.000, RR 2.87, 95%CI 1.37-6.12, P = 0.0035). Cultures positive for Legionella pneumophila serogroup 1, subtypes Pontiac, Philadelphia or Allentown, were obtained from eight patients. On the 39th day of the investigation it was found that the strain isolated in one of the cooling towers coincided with the serogroup, subtype and molecular profiles identified in clinical samples. CONCLUSIONS: Rapid coordination of clinicians, microbiologists, epidemiologists and environmentalists permitted the source of infection and the affected cases to be correlated within a few days.

A small outbreak of Legionnaires' disease in a cargo ship under repair.

It was reported that two mechanics working on a cargo ship under repair in the port of Barcelona had died after having fever. An investigation was made into the possibility of any additional cases and the presence of Legionella pneumophila in the ship they were repairing and in their hotel. The contaminated water system was treated with sodium hypochlorite. Both patients died after having been repeatedly diagnosed as having influenza. The two cases occurred among those who had been working with the pump of the ship's water system, while no cases were observed among the other workers (p = 0.02). Various serogroups of L. pneumophila were isolated from the ship's water pump and distribution system. However, organism of serogroup 1, subgroup Pontiac (Knoxville) were identified with identical deoxyribonucleic acid (DNA) patterns in the lung tissue of one patient and in the cooling water circuit valve of the ship's water pump. The first postintervention control water samples showed no further growth of legionella, but serogroups 4 and 8 were identified 8 months later. This legionellosis outbreak, although small, was highly lethal, probably due to the high levels of bacteria to which the patients were exposed and also because of the failure of correct diagnosis. International recommendations on prevention and control of legionellosis, which include ships under repair, are required.

Photorefractive keratectomy for myopic astigmatism using the emphasis erodible mask. Spanish User Group.

Photorefractive keratectomy (PRK) using the Summit emphasis erodible mask was performed on 229 eyes with myopic astigmatism. To analyze the efficacy and safety of the method, we evaluated the following: spectacle corrected visual acuity and refractive error as parameters of efficacy; corneal clarity, decentration of the ablation zone and complications as parameters of safety. Despite the short follow up (the longest was 12 months) our results show that the emphasis erodible mask appears to be an effective surgical method for correcting myopic astigmatism. However, we found a great number of complications and subjective symptoms that worsened the visual outcome. We conclude that the emphasis erodible mask has satisfactory efficacy but unsatisfactory safety.

Effects of pupillary dilation on automated perimetry in glaucoma patients receiving pilocarpine.

The authors studied 18 glaucoma patients receiving pilocarpine 2% therapy with automated static threshold perimetry using the Humphrey Field Analyzer 30-2 and STATPAC programs before and after instillation of 10% phenylephrine. The mean defect improved by an average of 3.14 decibels (dB) (standard deviation, 1.89 dB0 after administration of phenylephrine (P less than 0.001). The pattern standard deviation and the corrected pattern standard deviation also improved with dilation by 1.42 dB (P less than 0.01) and 1.73 dB (P less than 0.05), respectively, after dilation with phenylephrine. Comparisons of the unweighted means of threshold values in three zones of increasing eccentricity showed that the outer zone of the visual field had the greatest improvement after dilation. These findings indicate that pupillary dilation in glaucoma patients receiving pilocarpine therapy produces a nonuniform increase in threshold sensitivities and support the importance of consistent pupillary diameters on serial automated visual field examinations.

Specific antibody profile in human brucellosis.

The results of classic serological tests were compared with those of enzyme-linked immunosorbent assay in studies of immunoglobulins to Brucella in 761 serum samples from 75 patients with brucellosis. Except for five instances involving the IgM ELISA, all serological tests gave positive results at admission. Among the 63 patients without relapse, rates of persistent ELISA positivity (determined by the Kaplan-Meier method) 12 months after therapy were 25% for IgM, 69% for IgA, and 89% for IgG. Among the 12 patients with relapse, a second peak of ELISA IgG and IgA was often detected. The persistence of high serum antibody titers in patients without relapse was due mainly to IgG and was often associated with high titers at admission or with the presence of focal disease. Overall, serological changes were better detected by ELISA than by classic serological tests. While a second peak of ELISA IgG and IgA is a good marker of relapse, the persistence of high titers of IgG by itself is not a good predictor of chronic infection.

Specific antibodies detected during relapse of human brucellosis.

We studied 10 patients who had a relapse of brucellosis for significant serological changes during relapse. By the Coombs test, the pre-relapse and post-relapse median (range) titers of antibody to Brucella were 1:1120 (1:40-1:10,240) and 1:10,240 (1:40-1:81,920), respectively (P = .0069); by enzyme-linked immunosorbent assay (ELISA) for IgG, these values were 1:2240 (1:60-1:10,240) and 1:10,240 (1:160-1:81,920; P = .0069); by ELISA for IgA, the median titer increased 3.36 times but did not reach statistical significance (P = .0929); by tube agglutination, dithiothreitol (DTT) agglutination, and ELISA for IgM, median titers did not change. Nine patients had a significant titer increase by Coombs test and IgG ELISA, three had a significant increase by tube and DTT agglutination, none had significant increases by IgM ELISA, and one had no significant increase after relapse. Our findings show that for most patients with a relapse of brucellosis, there is an increase in IgG titers, as detected by ELISA and Coombs test, but no change in IgM titers.