Hospital-acquired infections and leading pathogens detected in a regional university adult acute-care hospital in Genoa, Liguria, Italy: results from a prevalence study.

BACKGROUND: A prevalence study aimed to update the epidemiological scenario of Hospital-Acquired Infections (HAI) was performed at the San Martino University Hospital of Genoa, the Regional Reference Adult-care Center in Liguria, Italy, with more than 1300 beds. MATERIALS AND METHODS: The investigation was performed in all the wards, except the Psychiatric Units, between 19th March and 6Ih April, 2007, using a one-day monitoring system for each ward. International standardized criteria and definitions for the surveillance of HAI were used for the collection of data, which were recorded in specific software for subsequent consolidation, analysis and quality control. RESULTS: The hospital infection control staff actively monitored 912 inpatients: a total of 84 HAI among 72 patients were diagnosed, with an overall prevalence of infections and affected cases of 9.2% (95% CI: 7.3-11.1) and 7.9% (95% CI: 6.1-9.7), respectively. Urinary Tract Infections (UTI) (30.9%), Respiratory Tract Infections (RTI) (28.6%) and Blood Stream Infections (BSI) (21.4%) were found to be the most frequent infections. As expected, both specific prevalence and localization of HAI varied considerably between wards, with the highest values recorded in Intensive Care Units (ICU) and in Functional Rehabilitation wards. RTI (26.3%) and BSI (13.2%) were found primarily represented in ICU, while the highest values of UTI (13.3%) were registered in Functional Rehabilitation Units. Enterococcus spp. (16.8%), Candida spp. (14%), Pseudomonas spp. (12.2), Staphylococcus aureus (10.7%), Escherichia coli (10.3%) and Coagulase-negative staphylococci (CNS) (9.3%) were the most frequent pathogens isolated. The overall rate of administration of antibiotics was 55.3% and penicillin (26.7%), cephalosporins (22.8%) and fluoroquinolones (17.9%) were found to be the leading antibacterial administered. CONCLUSION: Results of the present study have been, and are currently, used for orientating surveillance and control hospital policies, planning activities according to a rational and evidence-based approach.

Evaluation of microbial contamination of air in two haematology departments equipped with ventilation systems with different filtration devices.

BACKGROUND: Nosocomial infections (NI) are above all due to health-care workers practices, but also the contamination of the environment could lead to their rise in health-care facilities. Introduction. In the last years, the incidence of NI has increased due to a substantial rise in the number of immuno-compromised patients. These patients are often gathered in hospital areas declared at "high risk" of infection such as Hematology and Bone Marrow Transplant ward. In this study, we evaluated microbial contamination of the air in two divisions with high risk patients, focusing on the validity of the air system with correlation to the presence or not of the HEPA absolute filters. METHODS: An environmental surveillance study has been carried out in two Divisions of Haematology, in two different Hospitals. Investigations have been performed by sampling air and by analyzing bacterial and fungal growth on microbiology plates after an incubation period. RESULTS: Unit A, without HEPA filters in the ventilation systems, showed a gradual increase in the bacterial load 20 and 60 days after cleaning of the ventilation system. Mycetes and Aspergilli were not present in basal conditions, at 20 or 60 days after decontamination. Unit B, equipped with HEPA filters placed at the inlet vents, showed extremely low values of the bacterial load either in basal conditions or upon inspection 60 days after cleaning. No mycetes were present. DISCUSSION: From the results obtained, it was evident that following the cleaning operation, the quality of the air is excellent in both types of equipment, since no mycetes were present and the bacterial load was < 20 CFU/mc in all the sites tested. However, although in subsequent controls mycetes were absent in both types of equipment, a great difference in the suspended bacterial load was found: Unit B was close to sterility whereas in Unit A a progressive increase was observed.

Surveillance of hospital-acquired infections in Liguria, Italy: results from a regional prevalence study in adult and paediatric acute-care hospitals.

A multi-hospital prevalence study of hospital-acquired infections (HAIs) was carried out between 19 March and 6 April 2007 in Liguria, Italy, being the first to be performed in this region. Of the 29 existing public acute hospitals, 25 took part in the investigation (86.2%). In total, 3176 patients were enrolled in the study, representing a regional average bed-occupancy rate of nearly 70%. Three-hundred and ten HAIs were diagnosed from 283 patients, with an overall prevalence of infections and cases of 9.8% and 8.9%, respectively. Prevalence varied considerably between hospitals, ranging from 0 to 24.4% [95% confidence interval (CI): 15.53-33.27]. Urinary tract infections (UTIs) (30.0%) and respiratory tract infections (RTIs) (26.1%) presented the highest relative frequency, followed by bloodstream infections (BSIs) (14.8%), surgical site infections (11.6%) and gastrointestinal infections (6.5%). Intensive care units (ICUs) and haemato-oncological units showed the highest specific prevalence of HAI, respectively 42.5% (95% CI: 34.48-50.52) and 13.3% (6.28-20.32), with RTI and BSI as the predominant infections. Spinal units (33.3%; 13.14-53.46) and functional-rehabilitation units (18.9%; 17.75-24.06) demonstrated a high rate of urinary tract infections. Uni- and multivariate analyses were performed to assess the main risk factors and conditions associated with HAI, both overall and by site. Our study provides an overall picture of the epidemiology of HAI in Liguria, which may be usefully employed as a starting point to plan and organise future surveillance and control programmes.

Microbiological surveillance of hospital ventilation systems in departments at high risk of nosocomial infections.

The air in hospital wards with patients at high risk (Surgeries, Intensive Care Units and Bone Marrow Transplant Centers) has been surveyed less than the one in Operating Rooms. Therefore in this study we considered useful to verify the microbic contamination of the air of those wards evaluating the consistency of ventilation systems in relation also to the presence and location of HEPA absolute filters. Seven departments of Genoese San Martino Hospital at high risk of infection were taken into account. In there, environmental investigations have been performed by air samplings and by analyzing bacterial and fungal growth on plates after an incubation period. Almost 60% of all samples taken in wards yielded a positive result and the average values of bacterial and aspergillar charges measured at air flow emission openings decisively exceed the ones considered standard in operating rooms. Still, the average values of airborne bacterial charges were significantly higher in those wards equipped with central filters (p < 0.001), while as far as the aspergillar charge is concerned, no statistically relevant differences were noticed. In wards with ventilation system, the bacterial charge value raises from the emission grids to the middle of the room and to the aspiration grids, while the ward not equipped with a ventilation system presents in the middle of the room an average bacterial charge 2 to 10 times higher than the one in other wards. The average values regarding bacterial and aspergillar charges resulted quite high in all the departments surveyed. Nevertheless, if we take into account ventilation systems equipped with absolute filters HEPA located centrally or peripherally, it can be outlined that the air quality from the point of view of both microbic and aspergillar contamination turns out to be decisively better in systems with peripheral filters. Moreover, a compared analysis of the three Hematology wards allows us to infer that the presence of artificial ventilation systems can lower the bacterial and fungal compared with a ward with natural ventilation.

[Reduction of the incidence of nosocomial infections after assessing and revising the quality of assistance in a thoracic surgery unit]. / Riduzione del tasso d'incidenza delle infezioni ospedaliere in una U.O. di Chirurgia Toracica mediante verifica e revisione della qualità assistenziale.

An active surveillance for nosocomial infections has been lead in a Thoracic Surgery with the intention, first to point out their frequency and characteristics, and then to outline all the measures to remove the main risk factors checking the results obtained. A prospective incidence study has been promoted in a Thoracic Surgery in the years 2000, 2001, 2002. The analysis has been lead weekly gathering all necessary data from the health records and making laboratory tests to look for microbes growth in the air of Thoracic Surgery Operating Rooms. A nosocomial infections incidence of 13.3% among surgically treated patients has been registered in 2000. Deep surgical site infections were the most frequent localizations, and microbes isolated were Staphylococcus aureus and coagulase negative Staphylococcus with an high oxacillin resistance (70.6%-76.5%). From the observation of the risk factors the sterilization system has been modified and the assistance and environmental protocols have been improved. In the further evaluation period, a global reduction of nosocomial infections incidence (7.1%), of surgical site infections (from 10.1% to 4.5%) (p = 0.007), of Staphylococcus aureus and coagulase negative Staphylococcus isolations have been obtained even if short results in antibiotic resistances have been registered. Thoracic Surgery has to be considered an area at medium-high risk of nosocomial infections. The quite high incidence of nosocomial infections recorded at the beginning of the study in presence of prevalent deep surgical site infections from staphylococci with an high oxacillin resistance compelled to promote corrections. These lead to a remarkable decrease in incidence of nosocomial infections even if the same results can not be reached in antibiotic resistances.

Correlation between meteorological conditions and Parietaria pollen concentration in Alassio, north-west Italy.

The pollen grains in the atmosphere in different geographical areas differ according to the species present, the pollination seasons and pollen grain concentrations, but possibly the greatest contributors to this variability are the meteorological conditions. The aim of our research is to establish a possible correlation between Parietaria pollen concentration and meteorological conditions during the period from 1991 to 1995 in the town of Alassio (north-west Italy). As far as vegetation is concerned, the Mediterranean climatic conditions support the blooming of extensive grasslands in the environment surrounding the town; these grasslands mainly comprise Urticaceae and shrubs. The study demonstrates that the most influential parameters affecting the Urticaceae grain concentration upsurge are the absence of rainfall, a maximum daily temperature of about 21 degrees C, and a diurnal temperature range of about 5 degrees C. Moreover, our aeropalinological study indicates that this last parameter has the greatest influence on Urticaceae pollination. In fact, an increase in diurnal temperature range could be responsible for a dehydration of pollens resulting in a loss in mass. This grain lightness and volatility would ultimately permit atmospheric dispersion if there is a significant wind speed. On the other hand, days with rain or high relative humidity make pollens heavier, preventing them from flying long distances and therefore partially explaining the decline in airbone pollen concentration.

[The surveillance of the aeraulic and hydraulic system reduce environmental Aspergillus contamination in hospital]. / Utilità della sorveglianza degli impianti aeraulici e idraulici ai fini di ridurre la contaminazione aspergillare degli ambienti ospedalieri.

The aim of this work was to value the evolution of environmental Aspergillus contamination in hospital with respect to aeraulic system and bathrooms works. An analysis on levels of air and surface Aspergillus contamination were determined in patient's rooms and various common sites in a ward of an hospital in Genoa in 1999. As high contamination levels were found, in summer 1999 a radical disinfection and revision of the aeraulic system was settled. In spite of these interventions some samples maintained an high contamination level, even if from only two rooms, so a further disinfection of bathrooms and surfaces became necessary. A period of sampling was conducted after this last intervention until November 2002. At the beginning of our surveillance 59% positive samples and about 50% of them with high contamination level (>1000 CFU/m3) were found. After the revision of the aeraulic system the reduction of positive samples was significative (14.2%), besides all the positive samples regarded only two rooms. In the last valuation period, after a further disinfection of bathrooms and surfaces of the above mentioned rooms, all the samples taken resulted with a contamination level lower than 10 CFU/m3. This findings underlines the importance of environmental surveillance looking for all the contaminated sources; in particular the aeraulic and hydraulic system as well as the proximity hospital building yard not sufficiently protected.

Asthma and rhinitis in schoolchildren: the impact of allergic sensitization to aeroallergens.

This study aimed to evaluate the prevalence of asthma and rhinitis in schoolchildren living in the Genoa area by using a validated questionnaire and to investigate the prevalence of sensitizations using skin prick tests. An ATS modified questionnaire was given to 781 schoolchildren (all of them aged between 11 and 14 years) resident in the Genoa area. The main outcome of the present survey demonstrates a high prevalence of sensitized children (40.7%). Asthma and rhinitis prevalences are very high, mainly concerning the lifetime diagnosis. Actual asthma prevalence is about 6%, confirming ISAAC results, but rhinitis prevalence is notably higher and there is no difference between seasonal and perennial forms. Mites are the most important cause of sensitization and pollens are more frequently the cause of polysensitization. A distinct percentage of the asthmatic children and a higher percentage of rhinitic children are nonallergic. On the other hand, about one third of the sensitized children are without symptoms: They may be considered as subjects at risk of developing clinical respiratory diseases later. In conclusion, this study shows the importance of evaluating the existence of atopy, since there are many subjects with asthma and rhinitis who are nonallergic, and subjects at risk of developing respiratory allergies may be detected.

Differences in prevalence of allergic sensitization in urban and rural school children.

BACKGROUND: Environmental factors are important causes of sensitization, even though the effect of specific pollutants and the interaction between pollution and aeroallergens are not completely known. PURPOSE: To evaluate whether the exposure to pollutants or to allergens is a more important contributing factor in causing sensitization. METHODS: A group of 312 children living in the city and a group of 225 children living in a rural area, ages 11 to 14, were studied. All subjects underwent a skin prick test. The pollen counts were performed in the two different areas during the peak of the pollen season. At the same time the levels of ozone and suspended particulates were measured. RESULTS: The students living in the rural area showed a significantly higher percentage of sensitization than those in the city (P = .046). Sensitization to pollen was more frequent in the rural area (P < .001) but pet sensitization was more frequent in the city. More rural area students were sensitive to multiple allergens (P = .034). Pollen levels were higher in the rural area (P = .001). Both ozone and suspended particulate levels were higher in the city (P = .001 and P < .001, respectively). CONCLUSIONS: The degree of pollen exposure is a larger contributing pathogenic factor in inducing sensitization than air pollution.

[Surgical wound infection. Review of the guidelines and results of a prevalence study by the Presidio Ospedaliero de Voghera]. / Infezione della ferita chirurgica. Revisione delle linee guida e risultato di una indagine di prevalenza nel Presidio Ospedaliero di Voghera.

BACKGROUND: A prevalence study regarding hospital acquired infections and particularly surgical wound infections was performed from 17-4-1995 to 17-7-1995 in the Voghera hospital, a large one in Northern Italy. METHODS: The records of all subjects who have operated since at least 24 hours have been checked and the surgical wounds have been classified according to the guidelines of CDC (Atlanta). RESULTS: The prevalence rate of surgical wound infections was 13.73% of operated patients, confirming the seriousness of the problem of nosocomial infections surveillance. Pseudonomas aeruginosa (31.27%) and Staphylococcus aureus (21.92%) were the most frequently isolated organisms. CONCLUSIONS: Finally, behaviour guideline have been reproposed to try to reduce surgical wound infections for a best Quality of care in the light of a Regional credit.

Frequency and specific sensitization to inhalant allergens within nuclear families of children with asthma and/or rhinitis.

OBJECTIVE: The purpose of this study was to investigate the frequency of allergy in 85 families of pediatric patients with asthma and/or rhinitis. METHODS: Families enrolled were drawn according to a table of randomization, from those whose children were referred the outpatient clinic of the Pulmonology Department of Gaslini Institute (Genoa, Italy). In patients and in both their mothers and fathers, allergic sensitization to the three most common classes of inhalant allergens (house dust mites, pollens, and animal danders) was evaluated by skin prick test. RESULTS: As compared with their parents, children showed a similar prevalence of positive skin prick test (50.0% and 58.8%, respectively; chi 2 = 1.4; P > .1), but a significantly higher frequency of specific sensitization to house dust mites, pollens, or pets (P < .05, each chi 2). These differences were at least partially related to the higher frequency of polysensitization (i.e., sensitization to more than one class of allergens) in children than in their parents [chi 2 = 4.2, odds ratio (OR) = 2.3, 95% confidence interval (CI95%) = 1.0 to 5.1; P < .05). In addition, both in children (chi 2 = 5.8, OR = 11.3, CI95% = 1.4 to 81.5; P < .05] and in their parents (chi 2 = 7.4, OR = 4.8, CI95% = 1.5 to 16.7; P < .01), allergy to pollens was less frequent in monosensitized than in polysensitized families, while the prevalence of sensitization to house dust mites was similar in monosensitized and in polysensitized families. The analysis of the role of parental sensitization in the development of allergy in the offspring demonstrated that the prevalence of allergic children: (1) seemed to be higher, without reaching statistical significance, in families with sensitized parents than in those with non-sensitized parents (chi 2 = 0.41, P > .1) and (2) was higher in families with one or both polysensitized parents than in those with one or both monosensitized parents (chi 2 = 4.5, OR = 4.0, CI95% = 1.1 to 15.6; P < .05). In addition, within each family, the coincidence of sensitization to house dust mites was more frequent than that to pollens (60.0% and 36.0%, respectively; chi 2 = 7.6, OR = 4.5, CI95% = 1.5 to 14.3; P < .01), and it was not influenced by the number of parents sensitized to same allergen. CONCLUSION: These data support the concept that, in addition to genetic predisposition, other factors (i.e., environmental exposure) may influence the development of specific sensitization in children with respiratory symptoms. The different sensitization found in this study between children and their parents occurred in a generation span, so as it is more likely to be related to environmental changes than to genetic factors.

Increase of asthma and allergic rhinitis prevalence in young Italian men.

Our previous studies have reported that the prevalence of asthma was 2.89% and of allergic rhinitis 1.54% in Ligurian conscripts for the army during 1983. Since several authors reported an increasing prevalence of these diseases in different geographic areas, the aim of the present study was to evaluate the trend of prevalence rates in a same homogeneous group of Ligurian conscripts. The prevalence of asthma and allergic rhinitis was assessed in a group of 4310 young Ligurian men (18 years old) who had undergone medical examination for call-up to the navy during 1993, 1994 and 1995. Subjects were investigated by history, clinic visit, spirometry, metacholine bronchial challenge and skin prick test. The prevalence of asthma is 4.39% and of allergic rhinitis 2.2%. Comparing these results with previous data, a significant increase appears in this area 12 years later (respectively, p < 0.001 and p < 0.006). In addition, the association with asthma in allergic rhinitics increases from 41 to 77%, as well as an increasing trend appears for perennial allergens (i.e. mites and cat) and the polysensitizations increase from 48 to 67%. Possible explanations for these phenomena might be due to environmental factors (i.e. pollutants, viral infections, changes in domestic microenvironment).

Sensitization to airborne allergens in children with respiratory symptoms.

BACKGROUND: Allergy is one of the most common causes of respiratory symptoms in children and youth. OBJECTIVE: Evaluate the presence and the type of allergic sensitization in a paediatric population with respiratory symptoms. METHODS: We studied 564 consecutive children, 5 months to 17 years of age, with a male to female ratio (M/F) = 1.4, referred to our outpatient clinic in a 12-month period retrospectively. Patients were arbitrarily divided into four groups (grs) according to their age: gr1 = 5 months to 4 years old (181 patients), gr2 = 4 to 7 years (201 patients), gr3 = 7 to 10 years (96 patients), and gr4 = 10 to 17 years (86 patients). Sensitization to house dust mites, pollens, animal dander, and molds was determined by skin prick testing. RESULTS: Sensitization to at least one class of allergen occurred in 304 of the 564 patients (53.9%, M/F ratio = 2.0); the percentage of allergic patients increased with age as follows: 29.8% (54 patients) of the patients in gr1, 55.2% (111 patients) in gr2, 68.8% (66 patients) in gr3 and 84.9% (73 patients) in gr4 (chi(2) = 84.1, P < .01). In the entire allergic population and in gr1 to gr3, the most common positive allergic reaction was to house dust mites (P < .01, chi(2) test each comparison). In contrast, gr4 patients showed a nearly equal percentage of sensitization to pollens and to house dust mites (79.5% and 78.1% respectively) (chi(2) = 0.0, P = >.1). Sensitization to only one class of allergen occurred in 51.3% of the allergic patients and the percentage of these monosensitized patients tended to decrease from gr1 to gr4 (chi(2) = 15.2, P < .1). In the monosensitized group, sensitization to house dust mites was the most frequent in gr1 to gr3 (age <10 years) as in the whole sample. In gr4, the frequency of sensitization to house dust mites was similar to that of sensitization to pollens. On the contrary, within the patient group sensitized to two or more allergens (polysensitized patients), sensitization to house dust mites was as frequent as sensitization to pollens already in gr2 as compared with monosensitized patients. CONCLUSIONS: In children with respiratory symptoms, the percentage of allergic individuals was high and increased with the age of the patients. This phenomenon was associated with an age-related enhancement in the ratio of polysensitized to monosensitized patients and with an age-related increase in the frequency of sensitization to seasonal allergens (ie, pollens).

Bronchial and bronchoalveolar lavage after allergen challenge in atopic patients.

Twenty patients with allergic rhinitis and/or asthma sensitised to Dermatophagoides pteronyssinus were studied. On two consecutive days they underwent methacholine challenge and allergen bronchial challenge. 72 h after allergen challenge, fibreoptic bronchoscopy with bronchial (BL) and bronchoalveolar (BAL) lavage was performed. Specific IgE antibodies were measured both in serum and in BL from 14 patients. Both BAL and BL cell differentials were similar in patients with isolated early response to allergen and in patients with dual response. Patients with dual response to allergen showed higher levels of antigen specific IgE antibodies in BL than patients with isolated early response, while IgE levels in serum were similar in the two groups.

Late-phase asthmatic reaction to inhaled allergen is associated with early recruitment of eosinophils in the airways.

To determine whether a link exists between the recruitment of inflammatory cells in the airways and the development of the late-phase asthmatic reaction, we studied with bronchoalveolar lavage 54 asthmatic patients either at baseline (10 patients) or 4 h (11 patients), 24 h (13 patients), and 72 h (20 patients) after allergen inhalation challenge. Among the patients studied 4 h after allergen challenge, five were known to have a late-phase asthmatic response and showed a significant increase in the number and percentage of eosinophils in bronchoalveolar lavage compared with either patients without late-phase response (p less than 0.05) or unchallenged patients (p less than 0.01). Both the number and the percentage of eosinophils in bronchoalveolar lavage were also increased (p less than 0.05) in patients without a late-phase asthmatic reaction studied 24 h but not in those studied 4 h after allergen challenge. The numbers and the percentages of macrophages, neutrophils, or lymphocytes did not differ significantly among the different groups of patients. Of the patients studied 4 and 24 h after allergen challenge, only those with a late-phase asthmatic response showed an increased airway responsiveness to methacholine 1 h before bronchoalveolar lavage. We conclude that the development of the late-phase asthmatic response to allergen inhalation challenge and the allergen-induced increase in airway responsiveness are associated with an early recruitment of eosinophils in the airways.

Local immunotherapy with Dermatophagoides extract in asthma.

Local immunotherapy (LIT) with Dermatophagoides extract or placebo were administered to two groups of 11 patients with allergic asthma in a double-blind fashion. All patients received cromolyn sodium (20 mg four times a day) during treatments. Bronchial provocation tests with allergen and methacholine were performed before, 1 week, and 4 weeks after the end of treatments. Symptom score, drug consumption, and peak expiratory flow were monitored daily from 2 weeks before to 4 weeks after treatments. Compared to baseline, early bronchial sensitivity to allergen was significantly reduced both 1 week (p less than 0.0005) and 4 weeks (p less than 0.01) after LIT but not after placebo administration. Late bronchial reaction to allergen occurred similarly after placebo administration and LIT. However, in the group with LIT, the severity of late reaction was unchanged after treatment in spite of the significantly larger doses of allergen administered to provoke the early asthmatic reaction. Neither symptom score, nor drug consumption, nor peak expiratory flow were significantly different in the two groups before and during the treatment period even though both symptom score and drug consumption tended to be reduced after LIT. We conclude that LIT may be an effective and safe alternative to traditional immunotherapy.

Bronchial responsiveness is not increased by bronchoalveolar and bronchial lavage performed after allergen challenge.

Nonspecific bronchial responsiveness was studied in 23 allergic patients with a history of rhinitis and/or bronchial asthma who underwent fiberoptic bronchoscopy with bronchoalveolar and bronchial lavage (BAL-BL) 4h (Group A) or 24 h (Group B) after an allergen inhalation challenge. In all patients, the dose of methacholine causing an FEV1 fall of 15% (PD15) was determined at baseline, 24 h before allergen challenge. Methacholine bronchial challenge was repeated 1 h before BAL-BL in patients of both groups and again 12 to 14 h after BAL-BL in Group A and 24 h after BAL-BL in Group B. In patients of Group A, the values of methacholine PD15 after BAL-BL were not significantly different from those determined before BAL-BL. This was also the case in patients in whom bronchial responsiveness was increased after allergen challenge. In patients of Group B, methacholine PD15 was significantly decreased after allergen challenge, and this decrease was correlated with the occurrence and the severity of the late asthmatic reaction. Even in patients who showed dual asthmatic reactions and an increased responsiveness after allergen challenge, methacholine PD15 was not further decreased after BAL-BL. These data support the safety of a procedure combining bronchial allergen challenge with BAL-BL, which can be used for studies on the pathophysiology of bronchial asthma.