Masks: a ward investigation and review of the literature.
J Hosp Infect. 1986 May ;7(3):289-94. PMID: 2873176
The use of masks was related to the acquisition from patients of beta-haemolytic streptococci and Staphylococcus aureus in the nose/throat of staff in a burns unit. The study took place over 10 weeks; wearing multi-layer operating room masks for every visit to patient rooms had no effect on nose or throat carriage rates, although airborne dispersal from patients was high.