What are viruses, bacteria, and parasites?
Viruses, bacteria, and parasites are living organisms that are found all around us. They exist in water and soil, on the surfaces of foods that we eat and on surfaces that we touch, such as countertops in the bathroom or kitchen. Some bacteria live in our bodies and do not cause problems. Other kinds of bacteria (as well as parasites and viruses) can make us quite ill if they invade our bodies. Bacteria and viruses can live outside of the human body (for instance, on a countertop) sometimes for many hours or days. Parasites, however, require a living host in order to survive. Bacteria and parasites can usually be destroyed with antibiotics. On the other hand, antibiotics cannot kill viruses. Children with viral illnesses can be given medications to treat symptoms such as cough or runny noses, which can make them more comfortable, but antibiotics are ineffective against treating these infections. Bacteria, viruses, and parasites can cause a wide variety of illnesses, and can infect any
