Health care-associated infections (HAIs) are infections that patients acquire while receiving treatment for medical or surgical conditions, and many HAIs are preventable. HAIs can occur in a number of health care facilities, such as acute care hospitals, ambulatory surgical centers, outpatient care e.g. physicians’ offices and clinics, dialysis treatment facilities, and long-term care facilities e.g. rehabilitation centers and nursing homes. HAIs can be caused by bacteria, fungi, viruses, or other pathogens.