Microbiological evaluation of various parameters in ophthalmic operating rooms. The need to establish guidelines

Postoperative infections can be caused by a contaminated environment, unsterile equipment, contaminated surfaces, and infected personnel as well as contaminated disinfectants. In order to establish guidelines for microbiological monitoring, a detailed microbiological surveillance was carried out in an ophthalmic hospital.

Over a period of 21 months, we assessed environmental Bacteria Carrying Particle(BCP) load and surface samples weekly (n = 276); the autoclaving system once a month and repeated whenever the process failed (n = 24); the air conditioning filters for fungal growth once in four months (n = 15), and the disinfectant solution for contamination once in two months (n = 10). Additionally, the personnel involved directly in surgery were screened for potential pathogens such as Staphylococcus aureus and beta haemolytic streptococci.

On 14 (5.07%) occasions the environment in the operating rooms had a significant risk of airborne infections. Sterilisation of instruments in the autoclaves was unsatisfactory on 4 (16.66%) occasions. Samples from the filters of the air-conditioning units yielded potentially pathogenic fungi on 3 (20%) occasions. Personnel sampling revealed that 5 (8.77%) individuals harboured beta haemolytic Streptococci in the throat and 4 (7.01%) harboured S. aureus in the nasal cavity. The samples of disinfectant in use were not contaminated.

There is a need to standardise microbiological evaluation protocols for operating rooms.