Resistance of diseases to antimicrobials has increased dramatically in the last decade, with a deadly impact on the control of diseases such as tuberculosis, malaria, cholera, dysentery and pneumonia. As a result people with infections are ill for longer periods and are at greater risk of dying, and epidemics are prolonged.
Resistant organisms have no natural barriers; aided by international air travel they can move quickly from remote locations to have a worldwide impact. As resistance spreads, the effective life span of drugs shrinks; as fewer new drugs appear, the gulf widens between infection and control. In the case of malaria there is a double threat: on the one hand the malaria parasites are resistant to antimalarial drugs, and on the other the malaria-carrying mosquitos are resistant to insecticides. Rapid development of malaria drug resistance has already occurred in most areas of the world.
Resistant strains of the tuberculosis bacilli are also widespread: there have been alarming outbreaks of tuberculosis caused by multidrug-resistant strains in the United States. Both of the organisms that cause pneumonia, a major cause of death in children, are becoming increasingly resistant to drugs. The same is true of salmonellae, a leading cause of foodborne infections, and enterococci bacteria, which cause a host of complications in hospital patients. Hospital infections are a huge problem worldwide and are responsible for 70 000 deaths a year in the United States alone.