Evaluation of environmental bacterial contamination and procedures to control cross infection in a sample of Italian dental surgeries

OBJECTIVES—To perform a pilot study on bacterial contamination in some dental surgeries (n=51) in a local health unit in Brescia (Lombardy Region, Italy) and to evaluate the procedures to control cross infection used by the personnel to reduce the risk of infection in dental practice.
METHODS—A survey was carried out by interviewing 133 dental personnel with a questionnaire on the procedures used to control infection. The autoclaves, chemical baths (chemiclaves), and ovens present in the surgeries were tested for sterilisation efficiency with a spore test, and already packed and sterilised instruments were randomly sampled and tested for sterility. Microbial contamination of air, surface, and dental unit water samples were also studied.
RESULTS—The dental personnel did not generally follow the principal procedures for infection control: 30% of personnel were not vaccinated against hepatitis B virus, infected instruments were often not decontaminated, periodic checks of autoclave efficiency were lacking, and the knowledge of disinfection mechanisms and procedures was incomplete. High bacteriological contamination of water at dental surgeries was often found and total bacteriological counts in air samples were high. Surface studies showed widespread bacterial contamination.
CONCLUSIONS—On the basis of these results, an educational programme for the prevention of infective hazards has been prepared and carried out. The results of this pilot study will be used for planning a national survey.


Keywords: dental surgeries; bacterial contamination; cross infection control procedures     

Assessment of the rapid test based on an immunochromatography technique for detecting anti-Treponema pallidum antibodies

A rapid test based on an immunochromatography assay - Determine Syphilis TP (Abbott Lab.) for detecting specific antibodies to Treponema pallidum was evaluated against serum samples from patients with clinical, epidemiological and serological diagnosis of syphilis, patients with sexually transmitted disease other than syphilis, and individuals with negative serology for syphilis. The Determine test presented the sensitivity of 93.6%, specificity of 92.5%, and positive predictive value and negative predictive value of 95.2% and 93.7%, respectively. One serum sample from patient with recent latent syphilis showed a prozone reaction. Determine is a rapid assay, highly specific and easy to perform. This technique obviates the need of equipment and its diagnostic features demonstrate that it may be applicable as an alternative assay for syphilis screening under some emergency conditions or for patients living in remote localities.     

Cytologic features of plasmablastic lymphoma

BACKGROUND: Plasmablastic lymphomas (PBLs) were originally described exclusively in human immunodeficiency virus (HIV)-positive patients who presented with jaw or oral mucosa involvement. Recent studies have reported this neoplasm also in patients without HIV infection and involving sites other than head and neck. This lymphoma has a heterogeneous morphologic presentation but distinct phenotype. METHODS: Cytologic features from four cases of histologically confirmed PBL were evaluated. The cytology specimens were evaluated for criteria as follow: cellularity, cell size and shape, pleomorphism, cytoplasmic characteristics, chromatin pattern, nucleolar features, and mitotic figures. RESULTS: Specimens evaluated were two head and neck fine needle aspiration specimens, one anal smear, and one cerebrospinal fluid specimen. Atypical lymphocytes ranged from intermediate to large in size and demonstrated slight nuclear pleomorphism. The cytoplasm varied from scant to moderate in the alcohol-fixed slides. Nuclei were round with vesicular chromatin. Nucleoli varied from a prominent one to multiple small ones. Multinucleated cells and mitotic figures were easily identified in three of four cases. Tingible-body histiocytes were seen in one case. Ancillary studies in two cases demonstrated expression of CD138 with lack of CD20 expression. CONCLUSION: PBL is a variant of large cell lymphoma with heterogeneous cytologic findings but distinct immunophenotype. Knowledge of the cytomorphologic spectrum of PBLs and detection of CD138 expression by flow cytometry can be helpful in achieving a correct diagnosis.     

Results of replacement of cardiac valves by homologous dura mater valves.

Homologous dura mater valve was employed in a series of 533 patients in the period between January 1971 and May 1974. The dura mater was sterilized and preserved in 98 percent glycerol solution at room temperature. Important data were the following (1) no significant pressure gradient through the vale at rest; (2) no bacterial endocarditis; (3) two cases of fungal endocarditis; (4) no degeneration or retraction of the leaflets; (5) no thrombus formation in the valve; and (6) no anticoagulants were used in this series.     

Methodology to evaluation the habitual physical activity in men aged 50 years or more

OBJECTIVE: To describe the methodology for evaluating habitual physical activity that was adopted for a survey among the male population utilizing a questionnaire validated earlier. METHODS: The Baecke questionnaire on habitual physical activity was translated into Portuguese and then back-translated into English by two anglophone teachers. The final version of the questionnaire was applied in a cross-sectional epidemiological study done on 326 men aged 50 years or over. The internal consistency among the questions was evaluated using the Cronbach a statistic. The Spearman correlation coefficients between the habitual physical activity scores were calculated. Partial correlation coefficients with adjustments for age, body mass index and schooling were also calculated. RESULTS: There was satisfactory internal consistency in relation to the magnitudes of occupational physical activity and leisure-time physical exercises. Significant correlation was obtained between all the physical activity scores and the total habitual physical activity score, independent of age, body mass index and schooling. CONCLUSIONS: The Baecke questionnaire was found to be a practical instrument for assessing habitual physical activity that is quickly applied and easily understood, and it is recommended for epidemiological studies in Brazil.     

Genotoxic and ecotoxic effects of urban waste water disinfected with sodium hypochlorite or peracetic acid

Genotoxic and ecotoxicologic effects of urban wastewater disinfected with sodium hypochlorite or peracetic acid were analyzed. The formation of genotoxic species was studied by determining clastogenic and mutagenic activity of aqueous samples and their extracts with in vivo and in vitro tests, respectively. In particular, we have applied citogenetic tests to Allium cepa roots and Tradescantia inflorescence (Allium cepa test and Tradescantia/micronuclei test) and reversion test to Salmonella typhimurium according to the microsuspension procedure (Kado test). The latter is the method of choice for the analysis of complex matrices due to its high sensitivity and specificity. The mutagenic activity of disinfected effluents was similar to the corresponding untreated wastewater both sampled in four different periods. Therefore, the disinfection process did not seem to contribute to aquatic mutagenicity in the examined range of biocide concentration. The potential toxicity of disinfected wastewater for aquatic organisms was evaluated using Daphnia magna. The acute toxicity of peracetic acid in sewage was 0.4 mg/L (24 h E(L)C50). By comparing this value with peracetic acid concentrations detected in effluents from a pilot plant it is expected that treated wastewater would show acute toxic effects on aquatic organisms. Dissociation compounds (hydrogen peroxide and acetic acid) and possible by-products of peracetic acid did not seem to contribute significantly to the toxicity of sewage treated with peracetic acid.