The document discusses concepts of infection control, including definitions of community-acquired infections and nosocomial (hospital-acquired) infections. It notes that nosocomial infections can occur more than 48 hours after admission, after discharge, or among hospital staff. Risk factors for nosocomial infections include patient susceptibility, environmental factors, and transmission through healthcare workers or the hospital environment. Common sites of nosocomial infections are the urinary tract, respiratory tract, and surgical wounds. The document outlines methods for preventing nosocomial infections through aseptic technique, hand hygiene, cleaning and disinfection of equipment, and patient isolation when necessary.