Clean, separate, cook and chill--these are the basics of safe food handling, but millions of people become ill each year from food-borne bacteria, viruses and parasites. Most food poisoning is self-limited, causing acute symptoms of nausea and vomiting, diarrhea, and painful abdominal cramps, with or without fever. Treatment consists of rest and monitoring for dehydration. For infants, young children, and those with already compromised health or immune systems, food poisoning can lead to life-threatening complications or long-term disabilities.
Bacterial
Camplyobacter infection from eating undercooked chicken is the world's most common food poisoning. Symptoms include fever, abdominal cramps and diarrhea. The pathogen lives in the intestines of birds; most raw poultry is contaminated. The majority of cases last a week and are mild; rare serious complications include appendicitis or Guillian Barre, a neurological syndrome.
Animal foods may also be contaminated with salmonella, a bacteria found in the intestines of reptiles, birds and mammals. Salmonellosis, characterized by blood and mucus diarrhea, vomiting, fever, and abdominal cramps lasting four to seven days, is associated with warm weather and raw eggs. In rare cases, bacteria invade the bloodstream. Endocarditis, osteomylitis or Reiter's Syndrome, a debilitating form of arthritis, can result.
Food or water subject to fecal contamination from cattle is the most common route of infection by Escherichia coli 0157:H7, or E. coli. This bacteria causes severe abdominal cramps and bloody diarrhea. Complications of hemorrhage, anemia and kidney failure occur in approximately 3 to 5 percent of cases.
Viral
Viruses associated with food poisoning may be transmitted by food handlers that don't wash their hands after using the bathroom, or by shellfish harvested from sewage-contaminated water. Acute inflammation of the stomach and intestines, also known as gastroenteritis or stomach flu, is most often due to calcivirus or Norwalk-like virus infection. Vomiting produced by these viruses lasts 48 hours.
Multiple rotaviruses, noroviruses, adenoviruses, sapoviruses and astroviruses can also cause gastroenteritis. Illness typically begins one or two days after infection and may last from one to ten days. Prevention or correction of dehydration eliminates serious complications.
Hepatitis A infections have declined since a vaccine was developed. The virus is spread by fecal-oral contamination and associated with food handler violations. Symptoms of nausea, fatigue, body aches, dark foamy urine and jaundice appear two weeks after exposure. Hepatitis A does not cause chronic liver disease. Acute infection, which lasts up to eight weeks, confers lifetime immunity.
Parasitic
Giardia and Cryptospridium are microsopic parasites that inhabit the intestines of infected people or animals and can live outside the body for months. Parasites are commonly contracted in ponds, lakes or recreational water areas, but can be transmitted on unwashed fruit and vegetables.
Symptoms of Giardia may include fatigue, nausea, bloating and oily stools. Infection is self-limiting and lasts two to six weeks.
Cryptosporidium infection is characterized by watery diarrhea, which may be accompanied by fever, stomach ache and weight loss. Symptoms may come and go, lasting up to four weeks.
