[Nosocomial infections: main causative agents].

Introduction: Nosocomial Infections acquired within a care unit, may be related to various agents (Bacteria, virus, fungi, parasites...). The study purpose is to give relevent data on the main causative agents.

Main agents: The authors have shown the prevalent role of bacteria, mainly Enterobacteria, Staphylococcus and Pseudomonas; Legionella is also frequently isolated in some countries. Multiresistant Bacteria could be sometimes associated to nosocomial infections and severe infections. Among Nosocomial Virus: VRS, Rotavirus, Hepatitis B and C Viruses, HIV, Influenza Virus are cited. Fungal Agents (Aspergillus, Candida), Plasmodium, Non Conventional Agents (Prions) are also causative agents of Nosocomial Infection.

Conclusion: The Isolation of contagious Agent in a hospitalized patient is not the only criteria for Nosocomial Infection typing; Rigorous analysis needed to be done for every case.