Prediction of bacteria-carrying particle dispersion and distribution released from personnel in an operating room has been studied to decrease hospital related infections. It is focused on influence of foot traffic effect, specifically the number of personnel in the operating rooms, on the airflow field and the bacteria-carrying particle distribution. This was done by applying a numerical calculation to map the airflow field and Lagrangian DRW method for the particle phase. It is shown that, increasing number of staff persons within the OR disrupts the airflow pattern and enhances contamination in the area of open wound.