5. Antimicrobial Resistance

Antibiotic resistance can occur in a number of ways. Bacteria replicate rapidly, and mutations can arise in their DNA. If a mutation gives rise to bacteria that are less susceptible (and therefore more resistant) to the actions of the antibiotic, then this form of the bacteria will survive and continue to replicate. This is why it is so important to complete a course of antibiotic treatment – if a resistant form of the bacteria is allowed to proliferate in the body, later antibiotic treatment to combat a subsequent infection will have no effect.

Likewise, prolonged or overuse of antiviral drugs (such as those used to treat HIV) can lead to antiviral resistance. Usually, however, viral infections are removed by the body’s immune system. Community-wide immunisation programmes also reduce the risk of viral epidemics.