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Aims: Evaluation of the efficiency of peracetic acid in the disinfection of wastewater in a large treatment plant. Methods and Results: Over a period of 18 months 30 sample collections were made, each consisting of three samples taken from: raw incoming sewage, secondary effluent (after 10–12 h) and secondary effluent disinfected with 1·5–2 mg l–1 of peracetic acid (contact time: 20 min). Total coliforms and Escherichia coli declined from 107 MPN 100 ml–1 in the raw sewage to 102 in the disinfected effluent and the enterococci fell from 106 MPN 100 ml–1 to 702 MPN 100 ml–1. The reduction of bacteria increased with the rise in temperature and decreased with the rise in BOD5. Conclusions: Disinfection with peracetic acid reduced levels of faecal contamination by 97%, thus attaining the limit recommended by current Italian law (Escherichia coli ≤ 5000 MPN 100 ml–1) for discharge into surface waters. Significance and Impact of the Study: The process of disinfection with peracetic acid is easier to manage than other more common methods and the tests performed confirm that from the bacteriological point of view good results can be obtained for urban effluents. [ABSTRACT FROM AUTHOR]

The investigation was carried out by evaluating the microbiological characteristics of the water before and after treatment with Er:YAG laser and turbine. The study was carried out in 2 dental surgeries. In both cases the laser and dental units were served by two independent circuits, fed by the same potable tap water. Samples were taken from the water supplying and the water leaving the turbine and laser before and after treatment on the same patient. Total heterotrophic plate count was measured at 36 degrees C and at 22 degrees C, and the presence of Staphylococcus species and non-fermenting Gram negative bacteria was investigated. Bacterial contamination was found within the circuit, especially in the laser device. Pseudomonas aeruginosa was detected in only 1 sample of supply water, in 11.1 % and in 19.4 % of the samples from the turbine and the laser respectively. No evidence of Staphylococcus aureus was found. The contamination of supply water was low, whereas that of the water leaving the handpieces of the 2 devices was high, especially in the laser. Attention should be paid to the control of the water leaving laser devices, given the increasingly wide use of such instruments in dental treatment exposed to risk of infection.

A cross-sectional multicenter survey of Italian hotels was conducted to investigate Legionella spp. contamination of hot water. Chemical parameters (hardness, free chlorine concentration, and trace element concentrations), water systems, and building characteristics were evaluated to study risk factors for colonization. The hot water systems of Italian hotels were strongly colonized by Legionella; 75% of the buildings examined and 60% of the water samples were contaminated, mainly at levels of > or =10(3) CFU liter(-1), and Legionella pneumophila was the most frequently isolated species (87%). L. pneumophila serogroup 1 was isolated from 45.8% of the contaminated sites and from 32.5% of the hotels examined. When a multivariate logistic model was used, only hotel age was associated with contamination, but the risk factors differed depending on the contaminating species and serogroup. Soft water with higher chlorine levels and higher temperatures were associated with L. pneumophila serogroup 1 colonization, whereas the opposite was observed for serogroups 2 to 14. In conclusion, Italian hotels, particularly those located in old buildings, represent a major source of risk for Legionnaires' disease due to the high frequency of Legionella contamination, high germ concentration, and major L. pneumophila serogroup 1 colonization. The possible role of chlorine in favoring the survival of Legionella species is discussed.

Background: Since vaccinations are an effective prevention tool for maintaining the health of society, the monitoring of immunization coverage allows us to identify areas where disease outbreaks are likely to occur, and possibly assist us in predicting future outbreaks. The aim of this study is the investigation of the coverage achieved for compulsory (diphtheria, tetanus, polio, hepatitis B,) and recommended (pertussis, Haemophilus influenzae, measles-mumps-rubella) vaccinations between 1998 and 2002 in the municipality of Bologna and the identification of the subjects not complying with compulsory and recommended vaccinations., Methods: The statistics regarding vaccinal coverage were elaborated from the data supplied by the Bologna vaccinal registration system (1998-2000) and the IPV4 program (2001-2002). To calculate the coverage for compulsory vaccinations and cases of non-compliance reference was made to the protocol drawn up by the Emilia Romagna Regional Administration. The reasons for non-compliance were divided into various categories, Results: In Bologna the levels of immunization for the four compulsory vaccinations are satisfactory: over 95% children completed the vaccinal cycle, receiving the booster for anti-polio foreseen in their 3rd year and for anti-diphtheria, tetanus, pertussis at 6 years. The frequency of subjects with total non-compliance (i.e. those who have not begun any compulsory vaccinations by the age of one year) is generally higher in Bologna than in the region, with a slight increase in 2002 (2.52% and 1.06% in the city and the region respectively). The frequency of the anti-measles vaccination is higher than that of mumps and rubella, which means that the single vaccine, as opposed to the combined MMR (measles-mumps-rubella) was still being used in the period in question. The most common reason for non compliance is objection of parents and is probably due to reduction of certain diseases or anxiety about the possible risks., Conclusion: In Bologna the frequency of children aged 12 and 24 months who have achieved compulsory vaccination varied, in 2002, between 95% and 98%. As regards recommended vaccinations the percentage of coverage against Haemophilus influenzae is 93.3%, while the levels for measles, mumps and pertussis range from 84% to approx. 92%. Although these percentages are higher if compared to those obtained by other Italian regions, every effort should be made to strengthen the aspects that lead to a successful vaccinal strategy.

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.

We investigated Legionella and Pseudomonas contamination of hot water in a cross-sectional multicentric survey in Italy. Chemical parameters (hardness, free chlorine, and trace elements) were determined. Legionella spp. were detected in 33 (22.6%) and Pseudomonas spp. in 56 (38.4%) of 146 samples. Some factors associated with Legionella contamination were heater type, tank distance and capacity, water plant age, and mineral content. Pseudomonas presence was influenced by water source, hardness, free chlorine, and temperature. Legionella contamination was associated with a centralized heater, distance from the heater point >10 m, and a water plant >10 years old. Furthermore, zinc levels of <100 microg/L and copper levels of >50 microg/L appeared to be protective against Legionella colonization [corrected]. Legionella species and serogroups were differently distributed according to heater type, water temperature, and free chlorine, suggesting that Legionella strains may have a different sensibility and resistance to environmental factors and different ecologic niches.

Tests for Escherichia coli and E. coli O157 were carried out on meat samples collected from randomly chosen stores throughout the city of Bologna and suburban areas. The samples consisted of 25 g of loose minced beef, sometimes already shaped into meatballs or hamburgers, some of which were mixed with vegetables. The meat was purchased from retail outlets, open market stalls, and supermarket chains during 25 sampling visits from October 2000 to December 2001. For E. coli detection, Tryptone soya broth (TSB) supplemented with novobiocin and C-EC agar were used. Immunomagnetic separation with SMAC-BCIG-CT agar and chromogenic E. coli O 157 agar, API 20E system and agglutination latex test were used to detect E. coli O157; Vero cell assay and polymerase chain reaction (PCR) were used to assess toxin production and the presence of virulence genes.E. coli were detected in 45 (30.2%) of the 149 samples examined, mainly in the hamburger samples mixed with vegetables and in the loose minced beef. E. coli O157 was found in one sample of hamburger and two samples of hamburger mixed with vegetables (2%) collected from three different butcher's stores between July and October. All the strains of E. coli O157 and most cases of E. coli were found in meat from small retailers. The three strains of E. coli O157 were positive for verocytotoxin production. PCR analysis revealed genes coding for vt2 and one strain possessed the gene for eae A. Chromogenic E. coli O157 agar was found to be more selective and differential, allowing easier identification of suspected colonies with mixed flora and producing less false-positive colonies.

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.

The aim of this research was to evaluate the knowledge of cross-infection hazards in private dental practices, and their control procedures. The survey, carried out by questionnaire in 11 Italian cities, showed that dental personnel do not completely follow the main procedures for infection control. The interviewed subjects usually wear gloves (95.5%), masks (90.1%) and glasses (91.2%), less frequently caps (23.9%) and coats (54.9%). They use steam sterilizers (92.9%) and periodically check the effectiveness (80.6%). Regarding individuals protection, 20.5% is not vaccinated against HBV and only 55.2% of those previously vaccinated has checked their immunity. Moreover, the majority of subjects underestimate the infection hazards especially for air-transmitted diseases.

Social-demographic information of a total of 1249 students attending the University of Bologna was analyzed by means of an anonymous questionnaire containing 33 questions with particular reference to tobacco smoking and sports activity. Results revealed that 31.6% of the students practise some form of sports regularly (6 hours a week or more), 40.5% occasionally (at least an hour a week for 8 months in a year) and 27.9% do not take part in any kind of sport. Significant differences were seen between those that practise sports (60.4% are non-smokers and 33.5% are habitual smokers) and those that do not (52.9% are non-smokers and 40.1% smoke habitually). The smokers who are active in sports smoke a lower mean number of cigarettes a day than the inactive group and thus belong to the category of light smokers. They also smoke fewer cigarettes on days when they take part in sports activity. As far as knowledge of health risks is concerned, 21.1% of those who practise sports obtained a score between good and excellent compared to 15.9% of those who do not. Although on the whole the results appear to show a certain influence of sports on smoking habits, the kind of study we led and the differences in the number of smokers are not sufficient to consider sports practitioners as a group not at risk for behaviour harmful to the health. Further studies are necessary to verify the cause-effect relationship between sports activity and smoking habits.

The aim of this study was to investigate the smoking habits of a sample of second year high school students in Romagna (Northern Italy) by means of an anonymous self-administered questionnaire and the efficiency of a previous health education campaign. A sample of 2,691 16-year-old pupils (74% of the school population of this age) was randomly selected. Of these, 863 (32.1%) had participated in a prevention campaign while attending middle school. 19.1% of the students who had taken part in the campaign were smokers compared to 23.2% of those who had not. The students' smoking habits were found to be influenced by the type of school and by the role models (parents, siblings, friends, teachers). The campaign appears to have had good results, especially in places where it was carried out on a wide scale. Suggestions are made for making such campaigns more efficient.

Samples of drinking water were examined in order to evaluate the occurrence of two gram-negative bacteria: Burkholderia pseudomallei and B. cepacia. A total of 85 samples were collected from public and private buildings in the province of Bologna (Italy). Other bacteriological indicators (heterotrophic plate count at 22 and 36 degrees C) were also examined, together with physical and chemical parameters (temperature, pH, residual chlorine, total hardness and chemical oxygen demand (COD)). High levels of B. pseudomallei were recovered (mean value = 578 cfu/100 ml) in about 7% of samples, while B. cepacia was recovered in 3.5% (mean value = < 1) of the samples. The two microorganisms were found to correlate positively with heterotrophic plate counts at 22 and 36 degrees C, but not with the physical and chemical parameters taken into consideration.

The search for salmonella is the only bacteriological index included in Italian guidelines (in accordance with EU regulations) for the use of sewage sludge in agriculture. As a result, information regarding the presence of Listeria monocytogenes is rather limited. We therefore decided to carry out an investigation of Listeria in the sludge produced by the Bologna (Italy) treatment plant during the various phases of treatment. Five different types of sludge were analysed (primary raw, activated, thickened, digested and dewatered) in a total of 66 samples. The highest frequency and concentrations of Listeria species (100% and 2,743 MPN/g dry matter) and the lowest (63% and 6 MPN/g dry matter) were found in the activated and digested sludge respectively. These bacteria were mostly present in spring and autumn and positively correlated only with fecal streptococci. Four species were isolated: Listeria monocytogenes, Listeria innocua, Listeria welshimeri and Listeria grayi. Listeria monocytogenes (prevalent serotype 4b) was seen to be resistent to the biological oxidation but sensitive to anaerobic conditions during thickening and digestion. The dewatering process led to an increase in contamination. Since the sludge is used to fertilize land destined for vegetable farming our results show that it may represent a potential health risk.

A study was carried out on the presence of Gram-negative bacteria in the municipal waters of Bologna (Italy) undergoing softening using domestic ion exchangers with an automatic disinfection mechanism. The softening process was seen to cause a 15 fold increase in 22 degrees C and 36 degrees C heterotrophic plate counts. There was a 30 fold increase in Gram-negative bacteria and their number correlated directly with temperature and inversely with active residual chlorine. Organic matter had no effect on bacterial growth. The most commonly found bacteria were various species of Pseudomonas (87.6%) (Ps. acidovorans, Ps. denitrificans, Ps. fluorescens and Ps. testosteroni) followed by Aeromonas hydrophila (5.6%) and Stenotrophomonas (Xantomonas) maltophilia (3.8% in outgoing water). Pseudomonas aeruginosa (present in 5.6% of incoming water samples and 0.4% of outgoing water) and Yersinia enterocolitica (present in 4.3% of incoming water samples and 1.1% of outgoing water) did not find favorable conditions for growth on the ion exchange resins.

A study was carried out to evaluate the extent of contamination by Staphylococcus spp. and in particular by Staphylococcus aureus in dairy products on sale in the Bologna area. Staphylococcus aureus was found in 16.30% of the 135 cheese samples examined: 8.3% in soft cheese, 17.60% in blue cheese, 18.9% in semi-soft cheese and 25.0% in mozzarella-type cheese. The mean concentration was 2699 CFU/g in the 22 positive samples. The most commonly found species were Staphylococcus epidermidis (14.8%), Staphylococcus hominis (19.5%), Staphylococcus xylosus 2 (19.2%) and Staphylococcus cohnii (16.3%). Staphylococcus aureus was found mostly during the hot months while the other common species were found mostly in the period October-March.

A comparison was made of the inactivation rates of Arcobacter butzleri, coliphages, total coliforms, fecal coliforms, fecal streptococci and heterotrophic plate count in secondary sewage effluent using chlorine dioxide (2 and 4 ppm) and bromine chloride (4 or 8 and 12 ppm) as disinfecting agents. Using these doses the ClO2 gave higher reduction percentages (on average more than 99% at 4 ppm) than those obtained with BrCl. The average values of the fecal indicators are well within the legal limits. Arcobacter butzleri was more sensitive to the disinfectants than other bacteria while fecal streptococci were seen to be more resistant. From the chemical point of view no differences were seen between the two disinfectants except that the action of ClO2 was stronger regarding BOD5 than that of BrCl. With the exception of dichloromethane, the concentration of volatile halogenated compounds showed little variation and values were often lower than detection limits.

A study into the smoking habits of the Nursing School students of Bologna Province was carried out. 1077 (97.8%) of all students answered the self administered questionnaire and 44.6% of them were current or occasional smokers. 37.2% of males and 31.1% of females were current smokers. Overall nurse students smoked in a greater proportion in respect of coecal young people and females were generally lighter smokers and smokers of light cigarettes. Age, smoking habits of parents, siblings and partners were positively associated with smoking status of students while sex, civil status, education birth area, sport practice and parents profession did not show any significant association.

A study was carried out on alcohol intake among the students of the Schools for Trained Nurses in the province of Bologna by means of an anonymous especially prepared questionnaire. The series consisted of 1077 subjects: 753 females and 324 males aged between 16 and 40. 68.2% of males and 56.8% of females drank wine, l'81.3% of males and 61.8% of females drank beer and 65.3% of males and 46.2% of females drank spirits. While beer was the most popular drink, wine was on average drank in greater quantity. Alcohol intake was significantly related to sex (higher among males), area of origin (South) and cigarette smoking. The risk attributable to alcohol abuse are well known to almost all of the sample, above all those in the 2nd and 3rd years of their course. Nevertheless their alcohol consumption was not particularly different from that of students attending other High Schools. Regarding the sources, of their information about the risks, the 'mass media' was more quoted by the oldest students while 'family' was given by the younger students; the Nursing School was more often mentioned by both sexes in the 2nd and 3rd year of course. No relation however was found between the students knowledge of risks and actual consumption.

Microaerophilic organisms were monitored in sewage effluent undergoing two secondary treatments: air and oxygen-activated sludge. The mean numbers of Arcobacter cryaerophilus and thermophilic campylobacters detected in incoming sewage were 5639/100 ml and 1720/100 ml respectively. Secondary treatment in air tanks reduced the population of A. cryaerophilus by 97.1% and of thermophilic campylobacters by 99.08%, whereas treatment in oxygen tanks reduced the bacteria 97.8% and 99.63% respectively, showing that oxygen-activated sludge treatment was more effective. Subsequent tertiary treatment with 2 p.p.m. chlorine dioxide evidenced the removal of A. cryaerophilus to 99.9% and eliminated thermophilic campylobacters. Campylobacter jejuni and C. coli constituted 54.1% and 45.9% of 74 thermophilic campylobacter strains isolated. In air-activated sludge effluent C. jejuni was found more often, thus appearing more sensitive to oxygen. The most probable number assay used for detection of campylobacters, blood medium for enrichment and blood-free medium for plating, also appeared to be fit for A. cryaerophilus, the high density of which in urban sewage may be due to inflows from slaughterhouses.

Monitoring of "thermophilic" campylobacters in a sewage treatment plant in Bologna (Italy) has shown that incoming sewage contained a most probable number of 1630 campylobacters/100 ml. The secondary treatment in activated sludge tanks reduced 98.61% of campylobacters, 95.32% of fecal coliforms, 96.46% of fecal streptococci, 93.36% of salmonellas and 93.01% and 88.29% of BOD5 and COD respectively. Subsequent tertiary treatment with 3 ppm of chlorine dioxide for 15 min reduced 100% of campylobacters and salmonellas. Significant correlation coefficients were found in incoming sewage between campylobacters and salmonellas (p < 0.01) and between campylobacters and fecal coliforms (p < 0.02). Campylobacter jejuni and Campylobacter coli constituted 51.3% and 48.7% respectively of the 80 strains isolated. In incoming sewage 66% of the strains isolated were found to be Campylobacter jejuni whereas Campylobacter coli strains were prevalent in activated sludge effluent (69.7%). The greatest frequency of isolation and the higher counts were obtained during the Spring to Summer period with distinct peaks in May, June and July. This seasonability is probably due to the seasonal variation of campylobacter infections in man and animals.