Bacterial contamination of multidose ocular solutions. A prospective studyat the Grenoble Teaching Hospital.

The bacterial contamination rate of multidose ocular solutions used by hosp italized 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). T he most commonly identified organisms were part of the normal commensal flo ra. Three ophthalmology patients were using vials contaminated with Pseudom onas aeruginosa. A significant (P < 0.01) positive correlation was found be tween 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 preservative s present in ocular solutions. The standard practice of using ocular soluti on vials for seven days in health care facilities mayneed to be reappraised . Care should be taken to ensure that health care providers and patients un derstand the rules for ocular solution use. Unit-dose presentations may be preferable over multi-dose presentations for inhospital treatment.