Nosocomial infections are infections that arise during hospitalization or soon after discharge, and were neither present nor incubating at the time of admission.
Sources and risk factors
Hospitals and clinics concentrate vulnerable individuals and invasive interventions, creating opportunities for pathogens to spread. People who are already ill or immunocompromised are less able to mount defenses, and wounds or indwelling devices such as catheters, ventilators and intravenous lines bypass normal protective barriers. Microorganisms from the patient’s own flora or from other patients, visitors or healthcare workers may gain access through these routes. Gram-positive cocci like Staphylococcus aureus (including methicillin-resistant strains) and Enterococcus species, Gram-negative rods such as Escherichia coli and Klebsiella pneumoniae, and opportunists like Pseudomonas aeruginosa are frequent culprits. Fungal pathogens and viral agents such as norovirus can also be transmitted. Resistant organisms are a particular concern because they can withstand common antimicrobials and persist on surfaces, increasing the likelihood of outbreaks.
Prevention and control strategies
Reducing nosocomial infections requires strict attention to infection control practices. Hand hygiene with alcohol-based rubs or soap and water is the most effective measure. Sterilization and disinfection of instruments, proper aseptic technique during procedures, and routine cleaning of patient rooms and equipment reduce environmental contamination. Surveillance programs help identify outbreaks early and guide interventions. Isolation precautions such as contact or airborne precautions limit transmission from colonized or infected individuals. Antibiotic stewardship programs minimize selective pressure that drives resistance by promoting appropriate prescribing and de-escalation of therapy. Education of healthcare workers and patients about infection prevention, combined with facility design that supports these practices, helps protect patients and staff.
Nosocomial infections impose a significant burden on patients and healthcare systems by prolonging hospital stays and increasing morbidity, mortality and costs. Rigorous adherence to preventive measures and continuous surveillance are essential for reducing their incidence.
Related Terms: Hospital-acquired infection, MRSA, Infection control, Sterile technique, Antibiotic stewardship