[Prospective observational study of pneumonia in an Italian hospital]. / Studio osservazionale prospettico delle polmoniti in un ospedale italiano.

A prospective observational study was conducted during a two-year period to evaluate the prevalence of hospitalized pneumonia in six hospital units of the Bologna S.Orsola-Malpighi hospital (Italy). The selected units were: general surgery, general medicine, internal medicine, geriatrics, respiratory physiopathology and pneumology, with a total of 205 beds and around 4,800 admissions per year. Data were collected from the clinical cards and cases of pneumonia were distinguished by origin (community-acquired or hospital-acquired according to CDC definition), individual and clinical characteristics, and aetiology. The study involved 486 cases of pneumonia: 75 hospital-acquired and 411 community-acquired (84.6%). Patients affected by hospital-acquired pneumonia were older (average age 77 years) compared to community-acquired cases (74 years) and show a more homogeneous gender distribution (males: 48.0% vs 59.4%). Hospital stays (42 vs 21 days) and mortality rates (24.0% vs 11.7%) were significantly higher in hospital-acquired pneumonia. The incidence rate of nosocomial pneumonia was 7.4 per 1000 hospitalized patients and increased to 17-23 per 1000 in the pneumology and respiratory physiopathology units. Only 16.9% of cases had an aetiological diagnosis (14.1% community-acquired; 31.8% hospital-acquired); the most common isolates were S. aureus and P. aeruginosa. The hospital-acquired cases were caused by Gram-negative bacilli more often than the community-acquired cases, and infections were more frequently polymicrobial (37.5% vs 3.4%). In order to reduce morbidity and mortality due to pneumonia it is important to implement prevention measures in the community (i.e. specific vaccination campaigns), improve clinical protocols for aetiological diagnosis in hospitalised patients and increase epidemiological surveillance of hospital-acquired infections.

Control of Legionella pneumophila contamination in a respiratory hydrotherapy system with sulfurous spa water.

OBJECTIVE: To evaluate the effectiveness of different disinfection treatments in a spa water system contaminated by Legionella pneumophila and associated with a case of Legionella pneumonia. DESIGN: During an 18-month period, the spa water was analyzed by taking samples from the well, the recirculation line, and the final distribution devices (nebulizers and nasal irrigators). Various attempts were made to eradicate Legionella organisms by chemical and thermal shock. The final protocol consisted of heat shock treatment at 70 degrees C-75 degrees C for 3 hours, 2 nights per week, followed by a lowering of the water temperature to 30 deg C+/-1 deg C for use in the plant. In addition, 3 times a week superheated steam (at a pressure of 1 atmosphere) was introduced for 1 hour into the nebulization machines. SETTING: A spa at which sulfurous water was used for hydrotherapy by means of aerosol and nasal irrigation. PATIENT: A 74-year-old woman with legionnaires disease. RESULTS: After the case of infection occurred, L. pneumophila was isolated from the recirculation line at a concentration of 400,000 cfu/L and from the nebulizers and nasal irrigators at levels ranging from 3,300 to 1,800,000 cfu/L. The colonizing organisms consisted of a mixture of L. pneumophila serogroup 1 (12%) and serogroup 5 (88%). The shock treatment with chlorine dioxide and peracetic acid resulted in the eradication of Legionella organisms from the recirculation line but not from the water generated from the final distribution devices. After the restructuring of the plant and the application of thermal shock protocol, an evaluation after 12 months revealed no evidence of Legionella contamination. CONCLUSION: To prevent Legionella colonization, disinfection treatment is effective if associated with carefully selected materials, good circuit design, and good maintenance practices.

[Monitoring and control of opportunistic bacteria in a spa water used for aerosol hydrotherapy]. / Monitoraggio e controllo della contaminazione da batteri opportunisti in un'acqua termale erogata per aerosol e docce nasali.

A bicarbonate-sulphate-calcic water of a therapeutic spa was monitored for the presence of Legionella, Pseudomonas and Mycobacteria. The water was analysed by taking samples from the well, the feed tank and from the final aerosol generating devices of two different water lines, the former at 21-23 degrees, the second at 36-38 degrees. The bacteria in question were always absent from the well. Legionellae were found in the water of aerosol equipment: Legionella micdadei was isolated from 75% of samples, L. bozemanii from 75% and 50% (respectively 36-38 degrees and 21-22 degrees water lines) and other species of environmental Legionellae from 25% of samples. The water of aerosol equipment presented high total bacterial counts (10(3)-10(4) cfu/ml) and exspecially high concentrations of Pseudomonadaceae (10(2)-10(3) cfu/100 ml). These bacteria, unlike the Legionellae, were also isolated from the feed tank at mean concentrations of about 10(2) cfu/100 ml. Mycobacteria were found in 75 and 50% of samples collected from final devices, respectively from the heated and not heated water lines. The isolates were M. gordonae (85% of isolates) and M. fortuitum (15%), but at concentrations very low. Both treatments with sodium hypochlorite (20 ppm of residual chlorine) and peracetic acid (20 ppm) resulted in the reduction of total bacterial counts and elimination of Pseudomonas from the water in the tank, but not in elimination of Pseudomonas and Legionellae from the nebulizers. The disinfectants were evidently not able to efficiently reach all the points where Pseudomonas and Legionella had settled and grown. In order to obtain total abatement it was necessary to carry out a radical restructuring of the plant, involving the replacement of the old nebulizer benches with new aerosol equipment that could be subjected to a new system of programmed thermal shock.

Legionella waterline colonization: detection of Legionella species in domestic, hotel and hospital hot water systems.

AIMS: An evaluation was made of the prevalence of Legionella species in hot water distribution systems in the city of Bologna (Italy) and their possible association with bacterial contamination (total counts and Pseudomonadaceae) and the chemical characteristics of the water (pH, Ca, Mg, Fe, Mn, Cu, Zn and Total Organic Carbon, TOC). METHODS AND RESULTS: A total of 137 hot water samples were analysed: 59 from the same number of private apartments, 46 from 11 hotels and 32 from five hospitals, all using the same water supply. Legionella species were detected in 40.0% of the distribution systems, L. pneumophila in 33.3%. The highest colonization was found in the hot water systems of hospitals (93.7% of samples positive for L. pneumophila, geometric mean: 2.4 x 10(3) CFU l(-1)), followed by the hotels (60.9%, geometric mean: 127.3 CFU l(-1)) and the apartments with centralized heating (41.9%, geometric mean: 30.5 CFU l(-1)). The apartments with independent heating systems showed a lower level of colonization (3.6% for Legionella species), with no evidence of L. pneumophila. Correlation analysis suggests that copper exerts an inhibiting action, while the TOC tends to favour the development of L. pneumophila. No statistically significant association was seen with Pseudomonadaceae, which were found at lower water temperatures than legionellae and in individual distribution points rather than in the whole network. CONCLUSIONS: The water recirculation system used by centralized boilers enhances the spreading of legionellae throughout the whole network, both in terms of the number of colonized sites and in terms of CFU count. SIGNIFICANCE AND IMPACT OF THE STUDY: Differences in Legionella colonization between types of buildings are not due to a variation in water supply but to other factors. Besides the importance of water recirculation, the study demonstrates the inhibiting action of copper and the favourable action of TOC on the development of L. pneumophila.

[Environmental diffusion of Legionella spp and legionellosis frequency among patients with pneumonia: preliminary results of a multicentric Italian survey]. / Diffusione ambientale di Legionella spp e frequenza di legionellosi in pazienti affetti da polmonite: primi risultatidi uno studio multicentrico italiano.

A multicentric Italian investigation on legionnaires' disease is in course to clarify host factors as well as pathogen associated characteristics involved in the infection/disease. The main goal of the research plan is to account for some critical aspects concerning identification and prevention of legionellosis. To improve knowledge on factors associated with Legionella spp colonisation in hot waters, to detect cases and to characterize risk factors in subjects which develop pneumonia are specific objectives of the research programme. Preliminary results show that hot waters of houses and hotels are frequently contaminated (22.6% and 54.6%, respectively), mainly by L. pneumophila. Microbial concentrations were low in domestic waters (<1.000 ufc/l), but higher in samples from the hotels (geom. mean 1.85 x 10(3) ufc/l). Warming system, age of the plant, type of building were risk factors significantly associated with Legionella spp positivity. The active surveillance on patients affected by pneumonia with search for Legionella urinary antigen allowed the identification of 34 cases, 3 of which of nosocomial origin, corresponding to 4.2% of the screened pneumonia. After informed consent, 26 subjects were recruited for a case-control-study to clarify risk factors for the disease.

[Microbiological monitoring of mussels and clams collected from the shellfish-growing marine areas in Rimini Province]. / Monitoraggio microbiologico di mitili e vongole raccolti da aree di mare adibite a molluschicoltura della Provincia di Rimini.

A 5 years survey (1996-2000) was performed on the microbiological quality of shellfish (mussels and clams) collected from authorized shellfish-growing area of the North Adriatic Sea (province of Rimini). 7.0% of mussel samples (33/474) and 21.9% of clam samples (218/996) exceeded the legal limits for faecal indicators (Dlgs 530/92). The faecal contamination of shellfish was related to the organic pollution arriving from inland surface waters. In fact shellfish harvested near the coast were more contaminated, as well as shellfish grown in the surface layers of the open sea, where the fresh waters of the streams tend to stratify. Faecal contamination was also directly correlated with rainfall, probably because the atmospheric precipitation, increasing the flow of the streams, favoured the transport of organic substances and micro-organisms deriving from the soil washing and the municipal sewage effluents. Furthermore, when rainfall was particularly plentiful, sewage inflow could also exceed the hydraulic capacity of the treatment plants; thus making necessary to discharge untreated waste directly into surface waters. Salmonellae were found in 0.7% of clam samples. Although this percentage is very low, it shows that pathogenic micro-organisms are present in this area of sea. This finding, together with the high variability of shellfish pollution due to occasional factors as rainfall, emphasise the importance of the systematic monitoring of the microbiological quality of shellfish.

Legionella contamination of hospital water supplies: monitoring of private healthcare facilities in Bologna, Italy.

The hot water supplies of 11 private healthcare facilities in the city of Bologna, Italy, were monitored for the presence of Legionella spp. Four samplings were made in each establishment over a period of one year and in total 121 samples were collected from distribution points situated near the water-boiler and inside the wards (taps and showers). Legionellae were recovered from all the water supplies in question: Legionella spp. in 86.8% of samples, L. pneumophila in 82.6% of samples. L. pneumophila was found in all the water supplies at levels averaging above 10(4)cfu/L in five health facilities and reaching a maximum concentration of 10(7)cfu/L. The only parameter to have affected the presence of legionellae was the water temperature, which was seen to be inversely correlated to the concentration of Legionella spp. Despite the high levels of contamination from L. pneumophila, no cases of nosocomial Legionnaires' disease were reported during the period of the study.

Prevalence of Legionella spp. in swimming pool environment.

A study was carried out to evaluate the prevalence of bacteria of the Legionella genus in the water from the pools and showers of 12 swimming pools in the city of Bologna (Italy). Sampling took place four times for every establishment, once for each season of the year. Legionella spp. were found in 2 of the 48 pool water samples (L. micdadei and L. bozenanii) and in 27 of the 48 samples taken from the hot water of the showers: 19 were positive for L. pneumophila (10-19,250 cfu/l) and 18 for other species (20-6000 cfu/l). The contamination was seen to be consistent throughout the year, since the same species of legionellae were isolated at different samplings and in concentrations that did not reveal any seasonal trend. The legionellae and the Gram negative bacteria were not found in shower water with a temperature above 43 degrees C. However, in the samples of shower water with a lower temperature a statistically significant inverse correlation was seen between legionellae and Pseudomonas aeruginosa (r = -0.51; p<0.01) as well as between legionellae and Gram negative bacteria (r = -0.70; p<0.01). The potential risk of contracting infections from Legionella spp. in the swimming pool environment does not seem to be linked to the pool water, but to that of the showers. The water temperature of showers should therefore be maintained at a level high enough to prevent the reproduction of these bacteria.

Comparison of selective procedures for isolation and enumeration of Legionella species from hot water systems.

Various sample pre-treatment techniques and different growth media for the isolation of Legionellae from hot water supplies in public buildings were compared. A total of 102 hot water samples from taps and showers was examined. The highest recovery frequency was obtained with the heat pre-treatment method and using the selective medium GVPC. However, the results differed according to the concentration of legionellas. In the case of low plate counts (< or =5000 cfu l(-1)), the heat pre-treatment technique gave a significantly higher percentage of positive samples compared with other techniques (P < 0.05). With increasing concentration, the differences between the procedures decreased until they became statistically not significant for concentrations above 50 000 cfu l(-1). The direct inoculum method allowed a significantly higher detection of concentrations (P < 0.001) compared with heat and acid decontamination methods, which brought about a 67-68% reduction in detectable Legionellae. Heat decontamination techniques show greater sensitivity and specificity. However, they underestimate the number of legionellas. In environmental surveillance programmes, this underestimate must be taken into consideration when assessing the health risk.

Factors affecting the bacteriological contamination of commercial washing machines.

Wash water from self-service washing machines in three commercial launderettes of Bologna (Italy) were examined to verify which factors affect their bacterial contamination and to determine which procedures in the laundering process have the most significant effects on the removal of bacteria. Four washing formulas were compared: a delicates cycle (programmed temperature 25-30 degrees C; actual temperature: 28-31 degrees C); a whites cycle (programmed temperature: 80-90 degrees C; actual temperature: 50-57.5 degrees C); a delicates cycle with the addition of an oxygen-based bleach safe for delicate fabrics and a whites cycle with the addition of an oxygen-based bleach. Bacterial contamination of washing machines was higher in the launderette most heavely used, and, furthermore, it was in relation with the washing temperature and the use of bleaches. The low temperature laundering cycle (20-30 degrees C) did not guarantee elimination of bacterial content from either the inside of the washing machine or from the fabric being washed. Washing with water at a higher temperature, of about 55 degrees C, or adding an oxygen-based bleach to the low temperature cycle did ensure a significant reduction in bacterial recovery from water samples and fabrics, but did not prevent bacteria such as P. aeruginosa from surviving inside the washing machine. Only the addition of bleaches to the hot water program ensured the almost total elimination of bacteria and also guaranteed their elimination from protected parts of the drum.

Evaluation of disinfection treatment systems for municipal wastewater reclamation and reuse.

The efficiency of a number of tertiary treatment systems--filtration, ozonation, chlorination with low levels (TRC < 0.2 ppm) and high levels (TRC < 1 ppm) of residual chlorine--in the disinfection of secondary effluent was assessed in a purification plant treating mixed sewage of municipal (83%) and industrial mainly textile origin (17%). Maximum purification effect was observed when, following secondary treatment with biological oxidation, the sewage was submitted to combined filtration--ozonation treatment (reduction in bacterial indicators of from 4.9 to 7.2 log10 units) or with chlorination with high levels of residual chlorine (reduction in the bacterial indicators of between 2.8 and 4.6 log10 units). However, only ozonation reduced viral indicators with respect to inflow sewage by more than 3 log10 units, the limit considered acceptable for a biological treatment system with supplementary tertiary disinfection treatment. Ozonation however did not complete control all the biological forms present in the sewage, in particular the viruses, present in 36% of ozonized samples at concentrations of from 1 to 480 PFU/100 mL. Ozonation and high-concentration chlorination do not seem to be unfavorably influenced by wastes from laundry and deyng processing; achieving a complete decolorization of the treated effluent, they prove to the suitable treatments for mixed sewage of municipal and industrial mainly textile origin.