[Bacterial contamination of multi-dose ocular solutions. A prospective study at the Grenoble Teaching Hospital]

The bacterial contamination rate of multidose ocular solutions used by hospitalized patients was evaluated by culturing vial dropper tips and residual solution in vials. Bacterial colonies were counted and identified. Overall 39 (23.5%) selected vials were contaminated. Contamination rates were 17.7% (20/113) for vials used by ophthalmology ward patients and 35.8% (19/53) for vials used by internal medicine and gerontology patients (P < 0.02). The most commonly identified organisms were part of the normal commensal flora. Three ophthalmology patients were using vials contaminated with Pseudomonas aeruginosa. A significant (P < 0.01) positive correlation was found between vial contamination rate and duration of vial use. Vials containing an antimicrobial agent were less likely to be contaminated than vials without antimicrobials (P < 0.01). No clinical consequences of vial contamination were identified. However, ocular solution vial contamination carries a risk of infection. Our data are evidence of inadequate efficacy of preservatives present in ocular solutions. The standard practice of using ocular solution vials for seven days in health care facilities may need to be reappraised. Care should be taken to ensure that health care providers and patients understand the rules for ocular solution use. Unit-dose presentations may be preferable over multi-dose presentations for in hospital treatment.