R. VANFURTH Infection is an inseparable part of communal life, and
infections are more common and more severe in hospital communi- ties
because the sick are more easily infected than the healthy. However,
even though progress in the medical sciences has meant that many more
patients suftering from relatively severe diseases can be helped at
present, the use of more sophisticated and complex treatment leads to
impairment of the defence mechanisms in more patients than was the case
ten to twenty years ago, and these patients are also more prone to
develop an infection. Two questions are particularly relevant in this
context. 1) Under what conditions do hospital infections occur? Defects
of host defence mechanisms are of great importance in this respect. Such
defects can be due to the disease or to the treatment given to the
patient. 2) Which of the host defence mechanisms can be affected by a
stay in the hospital? Among the factors involved in the host defence
against infections (Table I), a number are especially important in this
respect. For instance, venepuncture, indwelling catheters, and surgery
all cause a breach in the surface structures. Anaesthesia causes
temporary impairment of mechanical factors. Vascularization may be
defective -- especial- ly in the aged and patients with diabetes
mellitus -- and this may complicate the healing of wounds in the skin
and mucous membranes after surgery.
