Which of the following causes highest risk of nosocomial infection to a patient -
Most common nosocomial infection → Urinary tract infection.

Most of the nosocomial UTIs occur after urinary catheterization.

Second most common nosocomial infection → Pneumonia.

Most of the nosocomial pneumonia are acquire through respiratory intubation, mechanical ventilation and suction of the material from the mouth.

Next most common cause of nosocomial infection → Surgical procedures.

Surgical procedures increase a patient's risk of getting an infection in the hospital. Surgery directly invades the patient's body giving bacteria a way into normally sterile parts of the body.
An infection may be acquired from contaminated surgical equipment or from health-care workers. Following surgery, the surgical wound can become infected.
Patient admitted for elective surgery
HIV patient coming in follow up OPD
Patient undergoing endoscopy
Patient admitted for normal delivery