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 make them comfortable, but antibiotics are ineffective
against treating these infections. Bacteria, viruses, and parasites can cause a
wide variety of illnesses, and can infect any of the organs of the body. Viruses
are often responsible for respiratory illnesses (such as the common cold) and
digestive illnesses (such as diarrhea). Bacteria can infect any part of the
body, but often cause diarrhea when they invade the digestive tract.
Diarrhea
Diarrhea can be caused by a variety of bacteria, viruses, and parasites.
Children can also have diarrhea without having an infection, such as when
diarrhea is caused by food allergies or as a result of taking medications (such
as antibiotics). A child is considered to have diarrhea when the child's bowel
movements are both more frequent than usual and looser and more watery than
usual.
Children with diarrhea may have additional symptoms including nausea,
vomiting, stomach aches, headache, or fever.
How does a child usually come in contact with bacteria, viruses, or
parasites that cause diarrhea?
- When touching the stool of an infected person (such as when touching
soiled diapers)
- When touching an object contaminated with the stool of an infected person,
and then ingesting the germs - this usually occurs by touching the mouth with
a contaminated hand (can occur at day care centers or at home in areas where
diapered babies play)
- By ingesting contaminated food or water
Why is infection with these organisms a concern?
Viruses, bacteria, and parasites that invade the digestive tract usually
cause diarrhea. Large amounts of water are lost with the diarrhea, leading to
dehydration in children. Children become dehydrated much quicker than adults,
and this can lead to serious problems if fluids are not replaced and the
infection treated.
Also, children with a severely weakened immune system are at risk for more
serious disease. Symptoms may be more severe and could lead to serious illness.
Examples of persons with weakened immune systems include those with HIV/AIDS,
cancer and transplant patients who are taking certain immunosuppressive drugs,
and those with inherited diseases that affect the immune system.