Final answer:
The four common sites associated with healthcare-associated infections are the urinary tract, surgical site, bloodstream, and lungs, often due to contamination from medical equipment or environments.
Step-by-step explanation:
The four sites commonly associated with healthcare-associated infections (HAIs) are the urinary tract, the surgical site, the bloodstream, and the lungs. These infections can occur due to a variety of reasons such as bacteria introduced via contaminated medical equipment like ventilators and intubation. For example, Staphylococcus spp. is often implicated in HAIs and can be introduced through medical devices inserted into the body, such as catheters or surgical instruments, leading to wound infections. Contaminated environments or healthcare workers can also transmit organisms that cause HAIs. Methicillin-resistant Staphylococcus aureus (MRSA), for instance, is a type of staph bacteria that is resistant to several antibiotics and is a common cause of HAIs. Adequate sterilization and infection control practices are critical in preventing these infections.