Nosocomial infections: Epidemiology, prevention, control and Surveillance

Nosocomial infections, also known as healthcare-associated infections (HAIs), represent a significant global threat to patient safety, contributing to increased morbidity, mortality, and healthcare costs. These infections, which arise during medical care and were not present at the time of patient admission, include bloodstream infections, ventilator-associated pneumonia, urinary tract infections, and surgical site infections. In addition to viruses and fungi like Candida and Aspergillus, the main culprits are bacteria, including Staphylococcus aureus, Pseudomonas aeruginosa, Enterococcus species, and multidrug-resistant strains like MRSA. Transmission routes span from environmental sources and healthcare personnel to contaminated equipment. According to epidemiological data, low- and middle-income nations have a higher incidence of nosocomial infections. Although they remain a serious concern in high-income settings as well. Prevention strategies emphasize environmental hygiene, hand hygiene, staff training, proper use of medical devices, and robust waste management. Effective control requires integrated hospital-wide infection control programs supported by active laboratory involvement. In order to track infection patterns, direct preventative measures, and enhance patient outcomes, surveillance is essential. This review provides a comprehensive overview of the etiological agents, types, epidemiology, and evidence-based measures for the prevention, control, and surveillance of nosocomial infections.