Hospital-acquired infection

Nosocomial infection
Other names	HAI (Healthcare-Associated Infections)
Contaminated surfaces increase cross-transmission
Specialty	Infectious disease

A hospital-acquired infection, also known as a nosocomial infection (from the Greek nosokomeion, meaning "hospital"), is an infection that is acquired in a hospital or other healthcare facility.^[1] To emphasize both hospital and nonhospital settings, it is sometimes instead called a healthcare-associated infection.^[2] Such an infection can be acquired in a hospital, nursing home, rehabilitation facility, outpatient clinic, diagnostic laboratory or other clinical settings. A number of dynamic processes can bring contamination into operating rooms and other areas within nosocomial settings.^[3][4] Infection is spread to the susceptible patient in the clinical setting by various means. Healthcare staff also spread infection, in addition to contaminated equipment, bed linens, or air droplets. The infection can originate from the outside environment, another infected patient, staff that may be infected, or in some cases, the source of the infection cannot be determined. In some cases the microorganism originates from the patient's own skin microbiota, becoming opportunistic after surgery or other procedures that compromise the protective skin barrier. Though the patient may have contracted the infection from their own skin, the infection is still considered nosocomial since it develops in the health care setting.^[5] The term nosocomial infection is used when there is a lack of evidence that the infection was present when the patient entered the healthcare setting, thus meaning it was acquired or became problematic post-admission.^[5][6]