Le but de cette étude a été de décrire une méthode de recensement des infections nosocomiales de site opératoire (ISO) et rapporter les résultats observés dans un service de chirurgie orthopédique et traumatologie.

Le recensement de ces infections repose sur le signalement par un praticien du service de bactériologie de tous prélèvements de site opératoire ayant une culture positive. Un collège de 4 médecins spécialistes décide du caractère infectant du germe et de l'origine nosocomiale de l'infection. Un dossier informatique est alors créé pour chaque patient ayant une infection de site opératoire regroupant des données cliniques, biologiques et microbiologiques. Le fichier informatique permet alors un suivi prospectif et une analyse des cas ainsi répertoriés.

Entre 2000 et 2002, 9397 interventions ont été réalisées et nous avons relevé 86 infections de site opératoire considérées comme nosocomiales. Les patients avaient un âge moyen de 58 ans, un index de masse corporelle moyen à 25,7 et 72 % avaient un score ASA supérieur ou égal à II. L'infection concernait une arthroplastie dans 23 cas, un acte de traumatologie dans 21 cas, le traitement d'une tumeur dans 24 cas. Elle a été diagnostiquée dans les 30 jours suivant l'intervention dans 75 % des cas, et après la sortie de l'hôpital dans 65,4 % des cas. Les infections monomicrobiennes étaient les plus fréquentes (n = 59) et un staphylococcus aureus a été isolé dans 80,23 % des infections. Mais en chirurgie tumorale, les infections plurimicrobiennes étaient statistiquement plus fréquentes associant des staphylocoques à coagulase négatif et des bacilles Gram négatif. Nous déplorons 6 décès directement imputables à une infection de site opératoire.

A program for the prevention of nosocomial infections, including operative site infections (OSI) is a legal obligation in France. According to the CDC, in orthopedic surgery, nosocomial infection is defined as any infection occurring within 30 days of operation, or within one year in the event of material implantation. No surveillance system has been validated and the rate of OSI is unknown in orthopedic surgery. We report the number of OSI observed during a three year period in our unit and describe the characteristic features.

Data were collected from the bacteriology reports on operative site samples with a positive culture. A group of specialists determined the infective nature of the germ and the nosocomial nature of the OSI. Clinical and bacteriological data were noted on a standard datasheet used for prospective follow-up of the number of cases and data processing. During a three-year period (2000, 2001, 2002), among 9397 orthopedic and traumatology operations performed, 86 OSI were identified. Mean patient age was 58 years and mean body mass index was 25.7. The ASA score was ≥ II for 72% of patients.

The OSI involved an arthroplasty in 23 cases, a traumatology procedure in 21, and tumor treatment in 24. The diagnosis was established within 30 days of operation for 75% and after discharge from hospital in 65.4%. Single-germ infections predominated (n = 59). Staphylococcus aureus was isolated in 80.23% of infections. For tumor surgery, the statistically more frequent multiple-germ infections associated coagulase negative Staphylococcus and Gram-negative bacilli. There were six OSI-related deaths.

Two criticisms can be formulated concerning our surveillance system. First, infections with no identified germ could be missed. The frequency of such infections has been estimated at 2.8 to 19% by different authors. Although patients are automatically recalled for consultation, we were unable to determine the number of patients lost to follow-up at one year. It was thus not possible to determine a precise rate of OSI. Data in the literature have not demonstrated any system providing an exhaustive surveillance, particularly because of the long postoperative period after material implantation. Excepting tumor surgery, Staphylococcus aureus infections predominated. Factors of risk of OSI include the patient's general status, particularly for arthroplasty. We had a mortality rate of 7% for our OSI, corroborating earlier studies and illustrating the severity of such infections.

Surveillance of OSI in orthopedic surgery requires the development of a system responding to the problem of a long observation period. It would be important to know the precise number of OSI and their characteristic features in order to develop comparison tools.