Nosocomial infections

Hospital-acquired or nosocomial infections—defined for epidemiological studies as infections manifesting more than 48 hours after admission—are common. They affect 1.4 million people worldwide at any one time and involve between 5 and 25% of patients admitted to hospital, with considerable associated morbidity, mortality, and cost.

Clinical features—the most common sites of nosocomial infection are the urinary tract, surgical wounds, and the lower respiratory tract. Bacteria are the most important causes, including Escherichia coli, Staphylococcus aureus (including methicillin-resistant Staphylococcus aureus, MRSA), enterococci, Pseudomonas aeruginosa, and coagulase-negative staphylococci. The principal risk factors are extremes of age, the severity of underlying acute disease (e.g. neutropenia, organ system failure), and chronic medical conditions (especially diabetes, renal failure, and alcohol abuse).

Prevention—between 15 and 30% of nosocomial infections are preventable, and hospital practitioners have a duty of care to minimize the risk of infection for their patients. Systematic surveillance to assess the incidence and prevalence of such infections, together with a regularly audited organized programme to prevent or minimize their impact, should be an important part of every hospital’s quality assurance system. Hospital managers must ensure appropriate staffing and resources to provide (1) access to advice from appropriately-trained experts in infection control; (2) surveillance of infection with regular feedback of the data to staff; (3) isolation of patients with infections, with appropriate arrangements for their nursing and medical management; (4) appropriate arrangements for carrying out procedures likely to increase the risk of infection, e.g. insertion of central venous lines; and (5) policies for outbreak management. All staff should receive regular education to ensure that they recognize that infection control is ‘everyone’s business’.