Surveillance of healthcare-associated infections in intensive care units is a priority because patients are at increased risk of infection due to their critical condition and the invasive devices to which they are exposed. Since 2004, surveillance coordinated by the Network for Alert, Investigation, and Surveillance of Healthcare-Associated Infections (HAIs) in intensive care has focused on infections associated with invasive devices for which a prevention strategy is essential: pneumonia (PNE), central venous catheter (CVC) colonization (COL) and associated infection or bacteremia (ILC/BLC), urinary tract infection (UTI), and bacteremia (BAC). Each year, participating departments collect data for 6 months on all patients hospitalized for more than 2 days (d). From January to June 2008, 174 departments included 25,225 patients: their mean age was 62 years and the male-to-female ratio was 1.6. At admission, 67% of patients were medical, 18% were emergency surgery, and 15% were elective surgery; 52% of patients were admitted from outside the hospital, 41% were short-stay patients, 4% were medium- or long-stay patients, and 3% were transferred from another intensive care unit; 9% of patients were trauma patients and 14% were immunocompromised; 53% received antibiotic therapy upon admission. Their mean IGS II score was 42.0 and the mean length of stay was 11.2 days. Exposure to invasive devices was common: intubation (64%), central venous catheter (61%), and urinary catheter (85%). Among 25,225 patients, 13.59% developed at least one infection, and 6.9% of CVCs were associated with CLS/LCS/BCS. The most frequently isolated microorganisms were P. aeruginosa (14.9%), E. coli (14.4%), S. aureus (13.3%), S. epidermidis (5.9%), and Candida albicans (5.1%); 36.0% of S. aureus strains were methicillin-resistant (48.7% in 2004). The observed incidence rates are 14.50 PNE per 1,000 days of intubation, 5.62 COL (and 0.90 BLC) per 1,000 days of CVC, 5.31 URI per 1,000 days of catheterization, and 3.52 BAC per 1,000 days of hospitalization. Patient characteristics and incidence rates vary significantly from one department to another. From 2004 to 2008 across the entire network, as patients were generally in more critical condition (ISG II, antibiotics on admission, immunosuppression, increased exposure to invasive devices), a decrease in incidence was observed for URIs (-36.2%), PNEs (-11.0%), and COLs (-2.4%), while an increase was observed for BACs (+6.3%) and BLCs (+28.5%), with the latter rate remaining very low. These data serve as a national benchmark, enabling a better understanding of NI in intensive care and improving their management through the feedback of results to participating units. (R.A.)