Bacterial air contamination of operating theatres and surgical wards of a university teaching hospital.

A study of the level and significance of air contamination in the four operating theatres and four surgical wards of the University of Nigeria Teaching Hospital, Enugu, Nigeria was carried out. A total of 48 air samples were taken from each of the operating theatres while a total of 36 air samples were taken from each surgical ward, using a "Casella slit Sampler". The means of the bacterial carrying particles per cubic foot of air varied, from theatre to theatre, from 12.29 to 14.29 (in the mornings) and 9.79 to 11.4 (in the evening). Statistically, these differences were insignificant (t-value < 1.96). Recognised pathogens were not recovered from both the air and the fomites in the operating theatres. However, free-living fungi were isolated. The air of the surgical wards showed levels of contamination from 20.39 to 35.28 (in the mornings) and 20.33 to 39.55 (in the evenings) bacterial carrying particles per cu.ft. of air. The differences between the counts in the mornings and evenings were also not statistically significant. Some pathogens were isolated from the air in the wards. The findings indicated that the level of air contamination of the surgical wards influenced the rates of post-operative wound sepsis.