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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 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.
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.
|Description||Escherichia coli O157:H7 (or simply E. coli) is just one of the hundreds of strains of the bacterium Escherichia coli. Most strains of E. coli are harmless and live in the intestines of healthy humans and animals. E. coli, however, produces a powerful toxin that can cause a severe infection. (The combination of letters and numbers in the name of the bacterium refers to the specific markers found on its surface and distinguishes it from other types of E. coli.)
An estimated 73,000 cases of E. coli infection occur in the United States each year. The Centers for Disease Control and Prevention (CDC) recognizes E. coli as an emerging food-borne illness. Infection often leads to bloody diarrhea.
|Transmission||Most E. coli illness has been associated with eating undercooked, contaminated ground beef. E. coli bacteria live in the intestines of healthy cattle and, although the number of organisms required to cause disease is not known, it is suspected to be very small. Meat becomes contaminated during slaughter, and organisms can be thoroughly mixed into beef when it is ground. Contaminated beef looks and smells normal. Other ways to transmit E. coli include:
Bacteria in diarrhea stools of infected persons can be passed from one person to another if hygiene or handwashing habits are inadequate. This is particularly likely among toddlers who are not toilet trained. Family members and playmates of these children are at high risk of becoming infected.
|Prevention||CDC recommendations for prevention of the infection include:
|Description||Salmonella is a bacteria that infects the intestines and causes diarrhea, fever, and abdominal cramps 12 to 72 hours after infection. At least 40,000 cases of salmonella are reported in the United States each year. The illness usually lasts four to seven days and most persons recover without treatment.
However, in some persons the diarrhea may be so severe that the patient needs to be hospitalized. In those patients, the salmonella infection may spread from the intestines to the blood stream and then to other body sites and can cause death unless the person is treated promptly with antibiotics. Infants and those with impaired immune systems are more likely to have a sever illness.
|Transmission||Salmonella may be spread by:
|Prevention||Since foods of animal origin pose the greatest threat of Salmonella contamination, do not eat raw or undercooked eggs, poultry, or meats. Remember that some sauces and desserts use raw eggs in their preparation, so be cautious of these, particularly in foreign countries. Also, follow these recommendations by the Centers for Disease Control and Prevention (CDC):
|Description||Rotavirus is the most common cause of severe diarrhea among children, resulting in the hospitalization of approximately 55,000 children each year in the United States and the death of over 600,000 children annually worldwide.
In the United States, the disease occurs most often in the winter, with annual epidemics occurring from November to April. The highest rates of illness occur among infants and young children, and most children in the United States are infected by two years of age. Adults can also be infected, though disease tends to be mild.
The incubation period for rotavirus disease is approximately two days. The disease is characterized by vomiting and watery diarrhea for three to eight days, and fever and abdominal pain occur frequently. Immunity after infection is incomplete, but repeat infections tend to be less severe than the original infection.
|Transmission||Rotavirus may be spread:
|Prevention||Scientists are working on a vaccine to give to children to prevent rotavirus. In 1998, a rotavirus vaccine was marketed that was thought to be linked to a few cases of a gastrointestinal illness called intussusception. That vaccine was withdrawn from the market. The new vaccine for rotavirus will not be offered until further testing is done.
Handwashing is a very important means of preventing the spread of rotavirus. Careful and frequent handwashing can prevent the spread of infection to other people.
The Centers for Disease Control and Prevention (CDC) recommends:
|Description||During the past 15 years, Giardia lamblia has become recognized as one of the most common waterborne diseases in humans in the United States. Giardia is a tiny parasite that lives in the intestines of people and animals. The parasite is passed in the bowel movement of an infected person or animal. It is found in every region of the United States and throughout the world.
Diaper-aged children who attend day care centers, international travelers, hikers, campers, and others who drink untreated water from contaminated sources, are most at risk for developing infection with Giardia. Several community-wide outbreaks of infection have been linked to drinking municipal water contaminated with Giardia.
|Transmission||People become infected after accidentally swallowing the parasite. Giardia may be found in soil, food, water, or on surfaces.
Some of the ways people can become infected with Giardia include:
|Prevention||The Centers for Disease Control and Prevention (CDC) recommends:
If your child has Giardia, avoid swimming in pools for two weeks after the diarrhea or loose stools have cleared. Giardia is fairly chlorine resistant and is passed in the stools of infected people for several weeks after they no longer have symptoms.
|Description||Cryptosporidium, often referred to as "crypto," is a tiny parasite that can live in the intestines of humans and animals. The parasite is protected by an outer shell that allows it to survive outside the body for long periods of time and makes it very resistant to chlorine disinfection.|
|Transmission||Cryptosporidium may be spread by:
Almost everyone has experienced a food-borne illness at some point in time. Contrary to popular belief, food-borne illnesses can occur when food is prepared at a restaurant or at home. If food is handled and prepared safely, most illnesses can be avoided.
All food may contain some natural bacteria, and improper storage or handling gives the bacteria a chance to grow. Also, food can be contaminated with bacteria from other sources that can make you ill. Contaminated or unclean food can be very dangerous, especially to children. According to the Centers for Disease Control and Prevention (CDC), each year food-borne illnesses kill 5,200 people of all ages. They also cause fever, stomach cramps, vomiting, and diarrhea in almost 80 million Americans, or about one in three people.
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