Gram-negative bacteria. The challenge of preventing cross-infection in hospital wards: a review of the literature.

Gram-negative bacteria are responsible for a high proportion of nosocomial infections, particularly among the critically ill and those in hospital for long periods. Colonization (asymptomatic carriage on the skin) occurs before the emergence of overt clinical infection (appearance of the signs and symptoms of disease) and is therefore worth reducing. Spread is principally via the hands of staff, so handwashing is the chief method of prevention. Gram-negative bacteria survive best in a moist environment and are more readily transferred via damp than dry surfaces; hands and equipment should therefore be kept as dry as possible. Good skin can also help prevent cross-infection as Gram-negative bacteria colonize damaged skin more readily than if it is in good condition.