Nosoref: a French survey of nosocomial infections (NI) surveillance in intensive care units (ICU) F L’Hériteau 1, C Alberti 2, G Troché 3, P Moine 4, Y Cohen 5, JF Timsit 6 and the Outcomerea group 1 Unité d’hygiène, Hôpital Bichat, Paris, 2 Biostatistics, Hôpital Debré, Paris, 3 ICU, Hôpital Mignot, Versailles, 4 ICU, Hôpital Lariboisière, Paris, 5 ICU, Hôpital Avicenne, Bobigny, 6 ICU, Hôpital Bichat, Paris, France

Introduction Nosocomial infections (NI) prevention and control is mandatory in intensive care units (ICU) in France; Surveillance and investigative methods differ from one ICU to another; Accordingly, comparison of results indicators between ICUs may be difficult or inaccurate; Better understanding differences between the methods used by various ICUs for NI surveillance is important in order to compare them We performed a national survey of these methods

Material and methods A questionnaire focusing on methods of NI surveillance in ICU was prepared by the working group, tested in 20 ICU and revised by an expert committee (C Brun-Buisson, J Carlet, A Le Pape). This was sent to all ICU in France and sent a second time to non responders. Finally, a random sample of non responders was interviewed by phone. Objectives of the study: – to describe the different methods used in French ICUs for NI surveillance and prevention; – to identify factors which could explain the differences between ICU. The following data were collected: - structure factors factors: type of center (secondary or tertiary care), type of ICU (medical, surgical, polyvalent, other); geographic location; number of beds and ventilators; - staff factors: number of physicians (senior and junior); number of nurses (day and night) and staff/bed ratio - equipment factors: microbiology lab in the hospital; computerization of microbiology lab data. Correspondence analysis was performed to try to identify the factors defining different categories of ICU.

Results (1) 252 ICU responded to the written questionnaire (44%); 142 (47% of non responders) were interviewed by phone Specialized Medical and surgical ICU staff completed the questionnaire more frequently than others ICUs interviewed by phone had more admissions and a lower medical staff/ bed ratio than ICU who returned the questionnaire *p<0.05 [q1-q3]: interquartile interval

NI are systematically mentioned in medical discharge reports in 72% of ICU Recording data on invasive procedures Prospective recording of proportion of patients undergoing invasive procedures (Mechanical ventilation [MV], central venous catheter [CVC], urinary catheter [UC]) is the best way to accurately estimate the incidence of NI. The proportion of ICU recording data on invasive procedures is shown below. Results (2)

Surveillance of invasive procedures (written responders) Proportion of ICU recording % of patients undergoing invasive procedures % of patients under invasive procedures is more frequently monitored when microbiology lab is in the hospital (93% of ICU) than where it is not: – 93% vs 69% (p=0.006) for MV; – 83% vs 41% (p=0.0002) for CVC; – 61% vs 24% (p=0.004) for UC. The median [interquartile interval] nurses/ bed ratio of ICU recording % of patients with UC is higher 0.44 [ ] than for ICU who do not 0.37 [ ] (p=0.01). Comparisons of other staff factors are not statistically significant. P<0.05 Less surveillance of MV and CVC in surgical ICUs Results (3)

Central venous catheter (CVC) infections surveillance 34% of ICU remove CVC at admission 55% of ICU remove CVC at discharge 48% of ICU systematically culture CVC sample in deceased patients Quantitative technique (Brun Buisson) is widely used in French ICU Central venous catheter infection surveillance (written responders) Type of CVC culture (written responders) Results (4)

Diagnosis of ventilator-associated pneumonia (VAP) (written responses) Qualit trach aspi : qualitative tracheal aspiration; quantt trach aspi : quantitative tracheal aspiration; PTC : plugged telescopic catheter; BAL : broncho-alveolar lavage; fibro-PTC : PTC under fibroscopy; brush : protected specimen brush; BAL-D : direct examination of BAL Results (5)

Nosocomial urinary tract infections (UTI) diagnosis and surveillance 30% of ICU perform systematic urine culture at admission 35% of ICU perform systematic periodic urine cultures for catheterized patients 67% of ICU include candiduria in the evaluation for UTI Results (6)

Multiresistant bacteria (MRB) carriage screening Screening for MRB carriers at admission : 77% of ICU in written responders 55% of ICU in oral responders Screening for MRB carriers during ICU stay : 67% of ICU in written responders 48% of ICU in oral responders Screening at admission is more frequent in teaching hospitals,than in non teaching (83% vs. 73% ; p=0.055). Screening during stay is more frequent in teaching hospital than in non teaching (78% vs. 59%, p=0.05). Screening at admission or during ICU stay is more frequent when the microbiology lab is located in the the hospital (80% and 69% respectively), than when it is not (36% and 20% respectively); (p< for both) MRB screening at admission (see below) and during ICU stay (data not shown) is less frequent in Northern and Western region than in others. MBR carriage screening at admission according to region Results (7)

MRB carriage screening and labeling Methicillin resistant Staphylococcus aureus (MRSA) and expanded spectrum beta-lactamase producing Enterobacteriaceae (ESBL) are the MRB most frequently looked for. Similarly, carriage these MRB are the most frequently labeled in ICU. Screening for or labeling of carriers are less frequent for cephalosporinase hyperproducing Enterobacteriaceae (E case), or Pseudomonas aeruginosa resistant to ticarcillin (ticar-R Pa), ceftazidime (cefta-R Pa) or imipenem (imip-R Pa) Screening for specific MRB Labeling of specific MRB carriers Results (8)

Multiple Correspondence analysis (MCA) (1) MCA indicated that 50 % of the structure parameters variance was explained by 3 dimensions that included the following variables: –dimension1university vs. non university hospital –dimension 2ratio number of ventilators/ number of beds > or < 1 –dimension 3ratio number of senior physicians/ beds > or < 1/3 76% of the VAP diagnosis parameters variance was explained by 3 dimensions including: –dimension 1ICU do (or do not) perform qualitative aspiration –dimension 2ICU do (or do not) use plugged telescopic catheter –dimension 3ICU do (or do not) initiate antibiotic therapy before results Note : MCA enables the identification of the core variables which are the principal factors describing any particular point of interest. These factors can then be used as the essential points to document in order to categorize ICUs.

75% of the CVC-related infection diagnosis parameters variance was explained by 3 dimensions including: –dimension 1local signs are (or are not) recorded at CVC removal –dimension 2ICU do (or do not) record % of patients undergoing CVC –dimension 3CVC are systematically (or not) removed at admission 74% of the nosocomial UTI surveillance parameters variance was explained by 2 dimensions including: –dimension 1ICU do (or do not) monitor % of patients with urinary catheter –dimension 2periodic urine cultures are (or are not) performed in patients with urinary catheter 75% of the MRB surveillance parameters variance was explained by 3 dimensions including: –dimension 1screening for ESBL and Acinetobacter carriage at admission and during stay –dimension 2labeling of ESBL and MRSA carriers –dimension 3screening for MRSA carriage during stay and at admission Multiple Correspondence analysis (MCA) (2)

Conclusion Procedures for surveillance and diagnosis of NI differ from one ICU to another. MRB policies also differ between ICUs. Using multivariate descriptive methods, the way the surveillance is organized is resumed by: –Structure: type of hospital; ventilator/bed ratio; senior physicians/bed ratio –VAP diagnosis procedures: qualitative aspiration; plugged telescopic catheter; antibiotic therapy initiated before microbiology results –CVC-related infection diagnosis: local signs recorded at CVC removal; % of patients undergoing CVC recorded; CVC systematically removed at admission –Nosocomial UTI surveillance: % of patients with urinary catheter monitored; perodic urine cultures in catheterized patients –MRB surveillance: screening for ESBL and Acinetobacter carriage; labeling of MRSA carriage; screening for MRSA carriage These factors must be taken into account when comparing ICUs on the basis of the results of NI surveillance.

Contacts: François L’Hériteau: For more data about Nosoref and The Outcomerea Group: