1 Generally, someone who has a MRSA infection stays infected for just under 10 days if they are treated by a doctor although many factors are involved and this duration can vary from person to person. Cover your wound. 2  Keep wounds that are draining or have pus covered with clean, dry bandages until healed. 3  Follow your healthcare provider’s instructions on proper care of the wound. 4  Pus from infected wounds can contain staph, including MRSA, so keeping the infection covered will help prevent the spread to others.