Microbial contamination in dental unit waterlines: comparison between Er:YAG laser and turbine lines.

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.

Compulsory and recommended vaccination in Italy: evaluation of coverage and non-compliance between 1998-2002 in Northern Italy.

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.

Detection of Escherichia coli O157 in bovine meat products in northern Italy.

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.

Relationship between mineral content of domestic hot water and microbial contamination.

The relationship between Legionella and Pseudomonas spp contamination and mineral content of domestic hot waters was investigated in a cross-sectional Italian survey. Pseudomonas spp contamination was associated with elevated Ca, but lower Fe and free chlorine content in the water. Waters with Cu concentrations > 50 microg/L prevented Legionella spp colonisation (OR = 0.14, 95% CI = 0.02-1.13), whereas the risk of legionellae occurrence increased in waters with Mn levels > 3 microg/L (OR = 2.37, 95% CI = 1.06-5.30). Furthermore, Mn was positively associated with the risk of colonisation by eterotrophic bacteria growing at either 22 and 36 degrees C. Legionella species and serogroups were differently distributed according to Cu and Mn concentrations, suggesting that Legionella strains may have a different sensibility/resistance to trace elements. A specific action of Cu as decontamination factor is suggested and the consideration of Mn as a risk indicator for bacterial colonisation and biofilm presence is proposed.

[Infection control in dental health care settings: results of a survey on current disinfection practices]. / La disinfezione in ambiente odontoiatrico: risultati di una indagine sulle procedure adottate.

This study was performed to identify which disinfection procedures are currently used in dental offices and to evaluate staff knowledge regarding infection control. Information was collected by means of a questionnaire to which 226 subjects responded. Glutaraldehyde was found to be the most commonly used disinfectant for surfaces/drill units, handpieces and instruments; however, half of the respondents did not specify which disinfectants they used. Eighty-four percent of the respondents reported contact times, which in some cases were found to be insufficient; 43,4% stated that containers are washed and disinfected each time the disinfectant is replaced; 58.8% reported that dental handpieces and instruments are precleaned prior to sterilization while 73% believe that increased attention during performance of work practices could reduce the risk of infection. These findings suggest that dental health care personnel need to be better sensitized toward infection control measures and should be offered periodical training on the proper implementation of practice guidelines.

Legionella contamination in hot water of Italian hotels.

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.

Legionella infection risk from domestic hot water.

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.