Postoperative wound infections and surgical face masks: a controlled study. Trial of the use of masks in the gynaecological operating theatre. Use of face masks by non-scrubbed operating room staff: a randomized controlled trial.
It has never been shown that wearing surgical face masks decreases postoperative wound infections. On the contrary, a 50% decrease has been reported after omitting face masks. The present study was designed to reveal any 30% or greater difference in general surgery wound infection rates by using face masks or not. During 115 weeks, a total of 3,088 patients were included in the study. Weeks were denoted as "masked" or "unmasked" according to a random list. After 1,537 operations performed with face masks, 73 (4.7%) wound infections were recorded and, after 1,551 operations performed without face masks, 55 (3.5%) infections occurred. This difference was not statistically significant (p greater than 0.05) and the bacterial species cultured from the wound infections did not differ in any way, which would have supported the fact tha the numerical difference was a statistically "missed" difference. These results indicated that the use of face masks might be reconsidered. Masks may be used to protect the operating team from drops of infected blood and from airborne infections, but have not been proven to protect the patient operated by a healthy operating team. A randomly controlled trial was performed on 41 women having gynaecological surgery in which the team of surgeons and nurses wore or did not wear masks. After major abdominal surgery, 3 of 5 patients in the unmasked group developed wound infections whereas no infection was observed in the 4 patients of the masked group. A greater number of Streptococci were also found by settle-plates on the operating table in the unmasked group. No infection was recorded after minor or vaginal surgery. Ambiguity remains about the effectiveness of wearing surgical face masks. The purpose of this study was to assess the impact on surgical site infections (SSIs) when non-scrubbed operating room staff did not wear surgical face masks.
                Eight hundred twenty-seven participants undergoing elective or emergency obstetric, gynecological, general, orthopaedic, breast or urological surgery in an Australian tertiary hospital were enrolled. Complete follow-up data were available for 811 patients (98.1%). Operating room lists were randomly allocated to a 'Mask group' (all non-scrubbed staff wore a mask) or 'No Mask group' (none of the non-scrubbed staff wore masks). The primary end point, SSI was identified using in-patient surveillance; post discharge follow-up and chart reviews. The patient was followed for up to six weeks.
                Overall, 83 (10.2%) surgical site infections were recorded; 46/401 (11.5%) in the Masked group and 37/410 (9.0%) in the No Mask group; odds ratio (OR) 0.77 (95% confidence interval (CI) 0.49 to 1.21), p = 0.151. Independent risk factors for surgical site infection included: any pre-operative stay (adjusted odds ratio [aOR], 0.43 (95% CI, 0.20; 0.95), high BMI aOR, 0.38 (95% CI, 0.17; 0.87), and any previous surgical site infection aOR, 0.40 (95% CI, 0.17; 0.89).
                Surgical site infection rates did not increase when non-scrubbed operating room personnel did not wear a face mask.
From the limited results it is unclear whether the wearing of surgical face masks by members of the surgical team has any impact on surgical wound infection rates for patients undergoing clean surgery.