Controlling disease

Asepsis is the absence of infectious organisms and aseptic techniques are aimed at minimising infection. Chemicals used to destry bacteria in the environment are usually referredto as disinfectants, those used diretly on people as antiseptics. It wasn't until well into the 20th century that antibiotics became available. These drugs could be used to treat patients already suffering a bacterial infection and they had a dramatic impact. All modern antimicrobial rugs work against microorganisms by the principle of selective toxicity - they interfere with the metabolism or function of the pathogen with minimal damage to the human host. When an antibiotic is taken, it may have 1 of 2 effects. It may be bacteriostatic, which means that the antibiotic or the dose used completely inhibits the growth and reproduction of the organism. This is usually sufficient for everyday infections as combined with the immune system, it ensures the pathogen is destroyed. However, sometimes the drug or dose given is bacteriocidal, meaning it will destroy any bacteria present. This is important in severe infections and is also useful in patients where the immune system is repressed. A broad spectrum antibiotic destroys a wide range of bacteria, a narrow spetrum antibiotic targets 1 or 2 specific pathogens. The effectiveness of…