Sources of intra-operative bacterial colonization of clean surgical wounds and subsequent post-operative wound infection in a Nigerian hospital.

The incidence of postsurgical clean wound infection in 101 consecutive operations was 1.98%. Staphylococci were the predominant bacteria cultured from the anterior nares of the patients and attending surgical personnel--and were found to colonize the wounds. The nasal carriage rates of Staphylococcus aureus amongst the patients and surgical staff were 12.1% and 17.% respectively. Group III and non-typeable (NT) S. aureus strains accounted for about 65% of S. aureus isolates cultured from the anterior nares. A low incidence of nasal carriage of S. aureus isolates correlated with low incidence of wound sepsis. The operating room air seemed considerably contaminated but this did not reflect in high incidence of postsurgical wound sepsis. Our results suggest patients microflora and operating room air were the major sources of intra-operative bacterial colonization of wound at this centre.