No further reproduction or distribution of the articles should proceed without the permission of the publisher. Introduction Medicine is becoming increasingly dependent on information technology, 1-3 and clinicians should be aware of the risks posed by computer viruses. Not surprisingly, given their name, computer viruses are analogous to biological viruses, and analogies can be drawn between them in the prevention, detection and treatment of infection. It is difficult to establish exactly what the first computer virus was, as several existed before Cohen called them viruses.
Genetic code evolves spontaneously to permit biological viruses to evade our immune system.
Computer virus code is specifically crafted by programmers to exploit the weaknesses and idiosyncrasies of computer software, usually the operating system software. New biological viruses are uncommon, but ingenious computer programmers are always designing new viruses. Brand new viruses can easily evade a computer's defences, but fortunately are quite rare. However, while biological viruses are self-contained particles, able to exist in isolation under suitable physical conditions, computer viruses are code which must reside on some form of storage medium. The mere existence of a biological virus does not qualify as infection.