What Are Stomach Bugs?

Stomach bugs are bacteria, parasites and viruses that cause inflammation of the gastrointestinal tract. This condition is known as gastroenteritis. An inflamed gastrointestinal tract interferes with the body's ability to absorb and process food correctly. Although stomach bugs are typically not deadly, such bugs are sometimes life-threatening to children, the elderly and people with compromised immune systems. The biggest danger with gastroenteritis is dehydration.

Viruses

• Rotaviruses, caliciviruses, adenoviruses and astroviruses cause most viral infections. Rotaviruses are the leading cause of gastroenteritis infections in children, according to the National Institute of Diabetes and Digestive and Kidney Diseases. Symptoms involve vomiting, fever, abdominal pain and diarrhea. Caliciviruses, such as noroviruses, mostly infect adults. Outbreaks of noroviruses typically occur between April and October, and symptoms include nausea, vomiting, diarrhea, fatigue, headache and muscle aches. Adenoviruses mostly infect children under 2 years old and can cause vomiting and diarrhea. Astroviruses mostly infect young children but they also infect adults. Symptoms include vomiting and diarrhea but are milder than noroviruses and rotaviruses.

Bacteria

• Campylobacter jejuni, E. coli, salmonella, shigella, staphylococcus and yersinia cause most bacterial infections. Bacterial infections are usually transmitted through contaminated food. This bacteria tends to contaminate food while being prepared by a person who has the bacteria on their hands or if the person comes in contact with it from a contaminated surface. The bacteria can also develop in foods such as dairy products that have been stored at improper temperatures. Vegetables are sometimes contaminated when they come in contact with water that contains traces of human or animal waste. These infections cause abdominal cramps, bloody stool, nausea and vomiting.

Parasites

• Some types of parasitic infections include E. vermicularis, G. lamblia, A. duodenale, N. americanus and E. histolytica. The E. vermicularis parasite is also known as roundworm and usually infects its host through contaminated food. The parasite lives in the large intestine and causes itching in the area around the anus. The G. lamblia parasite is usually a waterborne parasite that causes nausea, vomiting and diarhhea. A. duodenale and N. americanus are referred to as hookworm. Hookworm lives in soil and infects its host through skin and hair contact. Hookworm causes typical gastroenteritis symptoms such as vomiting and diarrhea. E. histolytica is found in human waste and is transmitted through contaminated food. This parasite causes severe abdominal pain, bloody stool and fever.

Prevention

• Although many of the parasites, bacteria and viruses that cause gastroenteritis have no vaccines or cures, preventive measures exist to avoid spreading or contracting them. Washing your hands thoroughly after using the toilet, before preparing food, after digging in the garden or soil and after changing diapers greatly reduce your risk of contracting or spreading stomach bugs. Hand sanitizers that contain alcohol are also effective against most of these stomach bugs. Washing vegetables before preparing them and avoiding raw seafood are also ways to prevent contracting stomach bugs.