Giovanni Battista Orsi

Hospital-acquired, laboratory-confirmed bloodstream infection: increased hospital stay and direct costs.

OBJECTIVES To determine increased hospital stay and direct costs attributable to hospital-acquired, laboratory-confirmed bloodstream infection (BSI), and to evaluate the matching variable length of stay (LOS). DESIGN Retrospective (historical) cohort study with 1:2 matching in intensive care units and surgical wards. SETTING A 2,000-bed university hospital in Rome, Italy. PATIENTS All patients admitted between January 1994 and June 1995 who had hospital-acquired, laboratory-confirmed BSI were considered cases; all others were eligible as controls. METHODS Two controls (A and B) were selected per case in a stepwise fashion. Controls in group A were selected according to the following six criteria: ward, gender, age, diagnosis, central venous catheter, and LOS equal to the interval from admission to infection in a matched case +/- 20% (LOS +/- 20%). Controls in group B were selected according to the first five criteria, but excluded LOS +/- 20%. RESULTS One hundred five of 108 patients were each matched with two controls. The matching appropriateness score was greater than 90%. With the use of controls in groups A and B, the case-fatality rates attributable to hospital-acquired, laboratory-confirmed BSI were 35.2% and 40.9%, respectively; the estimated risk ratios for death were 2.60 and 3.52 (P = .0001), respectively. The increased hospital stay per case attributable to hospital-acquired, laboratory-confirmed BSI was 19.1 (mean) and 13.0 (median) days for matched pairs in control group A and 19.9 (mean) and 15.0 (median) days for matched pairs in control group B. With controls in group A, the cost of increased hospital stay per patient attributable to hospital-acquired, laboratory-confirmed BSI was Euro 15,413. The additional cost per patient due to treatment was Euro 943, making the overall direct cost Euro 16,356 per case. CONCLUSIONS This study should make it possible to estimate the cost of hospital-acquired, laboratory-confirmed BSI in most hospitals after adjusting for incidence rate. It also confirmed the use of LOS +/- 20% as a matching variable to limit overestimation of increased hospital stay. To our knowledge, this is among the first such studies in Europe.

Hospital-acquired infection surveillance in a neonatal intensive care unit.

BACKGROUND Hospital-acquired infections (HAIs) represent an important cause of morbidity and mortality in neonatal intensive care units (NICUs). METHODS All neonates admitted for > 48 hours between January 2003 and December 2006 in the NICU of the teaching hospital Umberto I of Rome, Italy were considered. RESULTS Of the 575 neonates evaluated, 76 (13.2%) developed a total of 100 HAIs, including 36 bloodstream infections (BSIs), 33 pneumonias, 19 urinary tract infections, 8 conjunctivitis, and 4 onphalitis. There were 7.8 HAIs/1000 patient-days and 12.5 BSIs/1000 days of umbilical catheterization. Logistic analysis identified an association with mechanical ventilation (odds ratio [OR] = 3.05; 95% confidence interval [CI] = 1.75 to 5.31; P < .01) and birth weight <or= 1500 g (OR = 2.34; 95% CI = 1.36 to 4.03; P < .01). Thirty-five neonates (6.1%) died. Klebsiella pneumoniae (37.7%) and coagulase-negative staphylococci (28.6%) were the most frequently isolated microorganisms. Only 3 Candida spp determined BSIs (8.3%). BSI mortality was higher in infections with gram-negative pathogens (36.4%) than in infections with gram-positive pathogens (4.5%). CONCLUSIONS Although we found a low infection and mortality rate, attention should be directed toward antibiotic-resistant gram-negative pathogens.

Detection of BK polyomavirus genotypes in healthy and HIV-positive children.

Urine samples from 211 community children (3–7 years age), from 33 HIV type-1 infected children and from 56 HIV- negative children were collected and analyzed for the presence of BK virus (BKV) DNA by PCR. PCR amplifications were carried out using primers specific for the BKV structural region VP1. We also investigated the distribution of BKV subtypes by a restriction fragment polymorphism assay (RFLP). We demonstrated BKV DNA in 3.8% of 211 community children with a higher prevalence of subtype I. In HIV-1 positive children we detected BKV DNA in 2 urine samples (6%) out of 33, both belonging to subtype I. The HIV-negative cluster did not show any positivity to BKV DNA. The results confirm a more frequent primary BKV infection in children of 3–5 years of age and a higher prevalence in hospitalized children affected by HIV-1. The most relevant finding was that among both the community and HIV-1 positive children the subtype I was the most frequently detected.

Risk factors and clinical significance of ertapenem-resistant Klebsiella pneumoniae in hospitalised patients

Ertapenem-resistant Klebsiella pneumoniae (ER-Kp) is an emerging healthcare-associated pathogen. In order to identify risk factors associated with ER-Kp acquisition, the records of 100 patients from whom K. pneumoniae had been isolated between July 2008 and December 2009 were reviewed. These comprised 38 with ER-Kp (28 infected, 10 colonised) and 62 with ertapenem-susceptible K. pneumoniae (ES-Kp) (43 infected, 19 colonised). Multilocus sequence typing (MSLT) and porin gene investigation performed on 25 ER-Kp strains showed that 24 belonged to the ST37 lineage, expressing a novel OmpK36 variant and not expressing OmpK35. Breakthrough bacteraemia occurred in 13 (52%) of 25 bloodstream infections (BSIs). Among nine ER-Kp BSIs, five were complicated by breakthrough bacteraemia, of which four developed during carbapenem therapy. Among 16 ES-Kp BSIs, breakthrough bacteraemia developed in eight patients (50%), but only one occurred (12%) during carbapenem therapy. Logistic regression analysis showed that carbapenems (odds ratio: 12.9; 95% confidence interval: 3.09-53.7; P < 0.001), second generation cephalosporins (11.8; 1.87-74.4; P < 0.01), endoscopy (5.59; 1.32-23.6; P < 0.02), acute renal failure (5.32; 1.13-25.1; P=0.034) and third generation cephalosporins (4.15; 1.09-15.8; P < 0.01) were independent risk factors for acquisition of ER-Kp. Our findings confirm that prior use of certain antimicrobials, specifically carbapenems and cephalosporins, are primary independent risk factors for colonisation or infection with ER-Kp.

Surveillance and management of multidrug-resistant microorganisms

Multidrug-resistant organisms are an established and growing worldwide public health problem and few therapeutic options remain available. The traditional antimicrobials (glycopeptides) for multidrug-resistant Gram-positive infections are declining in efficacy. New drugs that are presently available are linezolid, daptomicin and tigecycline, which have well-defined indications for severe infections, and talavancin, which is under Phase III trial for hospital-acquired pneumonia. Unfortunately the therapies available for multidrug-resistant Gram-negatives, including carbapenem-resistant Pseudomonas aeruginosa, Acinetobacter baumannii and Enterobacteriaceae, are limited to only colistin and tigecycline. Both of these drugs are still not registered for severe infections, such as hospital acquired pneumonia. Consequently, as confirmed by scientific evidence, a multidisciplinary approach is needed. Surveillance, infection control procedures, isolation and antimicrobial stewardship should be implemented to reduce multidrug-resistant organism diffusion.

LACK OF ASSOCIATION BETWEEN CLINICAL AND ENVIRONMENTAL ISOLATES OF PSEUDOMONAS-AERUGINOSA IN-HOSPITAL WARDS

Seventy-three environmental and clinical isolates of Pseudomonas aeruginosa recovered from a single hospital over a 6-month period were compared for epidemiological type characteristics. Environmental isolates were obtained from sinks, taps and water, in rooms where patients were treated. The strains represented only six O-antigenic types and 8.2% of them were not typable. Serotype 011 was most frequent in the environment, whereas serotypes 06, 012 and 02,5 predominated among clinical isolates. More than 60% of all isolates belonged to four pyocin types (1, 10, 33 and 45), and approximately 80% were phage typable. Environmental isolates were more sensitive to antibiotics than clinical isolates. There was little correspondence between the types of strains of P. aeruginosa isolated from patients and those isolated from the environment. However, isolates of identical type were frequently recovered from different patients within the same clinic and were found to be related in time and location. We conclude that the environment was not an important source of P. aeruginosa infection and that transfer of organisms was mainly from patient-to-patient.

Surveillance and infection control in an intensive care unit

OBJECTIVE To evaluate the effect of an infection control program on the incidence of hospital-acquired infection (HAI) and associated mortality. DESIGN Prospective study. SETTING A 2000-bed, university-affiliated hospital in Italy. PATIENTS All patients admitted to the general intensive care unit (ICU) for more than 48 hours between January 2000 and December 2001. METHODS The infection control team (ICT) collected data on the following from all patients: demographics, origin, diagnosis, severity score, underlying diseases, invasive procedures, HAI, isolated microorganisms, and antibiotic susceptibility. INTERVENTIONS Regular ICT surveillance meetings were held with ICU personnel. Criteria for invasive procedures, particularly central venous catheters (CVCs), were modified. ICU care was restricted to a team of specialist physicians and nurses and ICU antimicrobial therapy policies were modified. RESULTS Five hundred thirty-seven patients were included in the study (279 during 2000 and 258 in 2001). Between 2000 and 2001, CVC exposure (82.8% vs 71.3%; P < .05) and mechanical ventilation duration (11.2 vs 9.6 days) decreased. The HAI rate decreased from 28.7% in 2000 to 21.3% in 2001 (P < .05). The crude mortality rate decreased from 41.2% in 2000 to 32.9% in 2001 (P < .05). The most commonly isolated microorganisms were nonfermentative gram-negative organisms and staphylococci (particularly MRSA). Mortality was associated with infection (relative risk, 2.11; 95% confidence interval, 1.72-2.59; P < .05). CONCLUSION Routine surveillance for HAI, coupled with new measures to prevent infections and a revised policy for antimicrobial therapy, was associated with a reduction in ICU HAls and mortality.

Building a benchmark through active surveillance of intensive care unit-acquired infections: the italian network SPIN-UTI

The Italian Nosocomial Infections Surveillance in Intensive Care Units (ICUs) (SPIN-UTI) project of the Italian Study Group of Hospital Hygiene (GISIO - SItI) was undertaken to ensure standardisation of definitions, data collection and reporting procedures using the Hospital in Europe Link for Infection Control through Surveillance (HELICS)-ICU benchmark. Before starting surveillance, participant ICUs met in order to involve the key stakeholders in the project through participation in planning. Four electronic data forms for web-based data collection were designed. The six-month patient-based prospective survey was undertaken from November 2006 to May 2007, preceded by a one-month surveillance pilot study to assess the overall feasibility of the programme and to determine the time needed and resources for participant hospitals. The SPIN-UTI project included 49 ICUs, 3053 patients with length of stay >2 days and 35 498 patient-days. The cumulative incidence of infections was 19.8 per 100 patients and the incidence density was 17.1 per 1000 patient-days. The most frequently encountered infection type was pneumonia, Pseudomonas aeruginosa being the most frequent infection-associated micro-organism, followed by Staphylococcus aureus and Acinetobacter baumannii. Site-specific infection rates for pneumonia, bloodstream infections, central venous catheter-related bloodstream infections and urinary tract infections, stratified according to patient risk factors, were below the 75th centile reported by the HELICS network benchmark. The SPIN-UTI project showed that introduction of ongoing surveillance should be possible in many Italian hospitals. The study provided the opportunity to participate in the HELICS project using benchmark data for comparison and for better understanding of factors influencing risks.

Does hospital work constitute a risk factor for Helicobacter pylori infection

Summary The aim of this study was to assess whether clinical work constitutes a risk factor for Helicobacter pylori infection among employees in hospitals. The prevalence of H. pylori infection was analysed in 249 individuals employed in a university teaching hospital according to three categories of hospital workers: (A) personnel from gastrointestinal endoscopy units (N=92); (B) personnel from other hospital units with direct patient contact (N=105); and (C) staff from laboratories and other units with no direct patient contact (N=52). Stool samples from each subject were examined with a validated enzyme-linked immunosorbent assay for the presence of H. pylori antigens. A questionnaire inquiring about sociodemographic and occupational characteristics was completed by each participant. The prevalence of H. pylori infection was 37.0% in group A, 35.2% in group B and 19.2% in group C (P<0.05). Among the different healthcare categories, nurses had a significant higher prevalence of H. pylori infection (P<0.01). No significant association was found between the length of employment or exposure to oral and faecal secretions, and H. pylori infection. Hospital work involving direct patient contact seems to constitute a major risk factor for H. pylori infection compared with hospital work not involving direct patient contact.

Multidrug-resistant Acinetobacter baumannii outbreak in an intensive care unit.

Abstract Carbapenem-resistant Acinetobacter baumannii was isolated from 15 colonized or infected patients (carriers) between April and July 2004, in a teaching hospital ICU in Rome, Italy. All isolated strains were susceptible only to gentamicin, ampicillin-sulbactam and colistin and displayed the same Random Amplified Polymorphic DNA (RAPD) 1 pattern. Twelve out of 15 strains were susceptible to tigecycline, whereas the remaining three showed intermediate susceptibility. Although infection control measures were reinforced and carriers isolated in separate rooms, A. baumannii transmission continued. Therefore, finally A. baumannii carriers were moved to another available subintensive unit, which was re-equipped, and cared for by dedicated personnel, whereas only the non infected/colonized patients remained in the ICU. This study shows that during an outbreak by multiresistant A. baumannii it may be indispensable to geographically isolate not only patients but also dedicated staff.