5.7:
Healthcare Associated Infections I: Iatrogenic, Exogenic and Endogenic
Infections contracted at a healthcare facility are known as healthcare-associated infections or HAIs. For example, surgical site infection.
HAIs also include work-related infections among healthcare staff.
HAIs incubate after forty-eight hours of hospitalization and up to thirty days after discharge.
The source of HAIs may be exogenous or endogenous.
Exogenous infections occur when a pathogen enters a patient's body from their environment, for example, inadvertently spread from contact with a contaminated surface.
In contrast, in endogenous infections, the body's normal flora of microorganisms may become pathogenic. It usually occurs when the host is susceptible due to a lowered immune system from illness or treatment.
For example, overuse of antibiotics alters the balance of normal flora by causing a reduction in microbial diversity. It can also select for antimicrobial-resistant strains, and make the body more susceptible to infection.
Patients may be susceptible to iatrogenic infections caused by certain diagnostics or treatments.
For example, using a urinary catheter over an extended period increases the risk of catheter-associated urinary tract infections.
5.7:
Healthcare Associated Infections I: Iatrogenic, Exogenic and Endogenic
Healthcare-associated infections (HAIs) occur in a healthcare facility while a person receives care for another ailment. This category also includes work-related infections among healthcare staff.
HAIs significantly increase the cost of health care. Extended stays in healthcare institutions, increased disability, increased costs of medications, including specialized antibiotics, and prolonged recovery times add to the patient's expenses and the healthcare institution and funding bodies. Common HAIs include:
- • Central line-associated bloodstream infections (CLABSI)
- • Catheter-associated urinary tract infections (CAUTI)
- • Ventilator-associated pneumonia (VAP)
- • Methicillin-resistant Staphylococcus aureus infection (MRSA)
- • Surgical site infections (SSI)
- • Clostridium difficile infection.
For all these types of infections, symptoms may appear within forty-eight hours of admission or thirty days after discharge.
HAIs may be exogenous or endogenous in origin. Exogenous infections occur when a pathogen enters a patient's body from their environment. For example, a healthcare worker can spread the infection due to poor adherence to infection control practices. In contrast, the body's normal flora may cause an endogenous infection; they may act as opportunistic pathogens when the host is susceptible.
The body's normal flora is a stable population of microorganisms living on the surface and deep layers of skin, saliva, oral mucosa, gastrointestinal, and genitourinary tracts. Under normal conditions, they help maintain health, but an infection may result when the body is stressed or immunity is compromised.