By Lonny Stark
May 17, 2006
E. coli O157:H7 — Although it doesn’t typically cause a fever, this bacteria inflicts more severe abdominal cramps as well as bloody diarrhea. In extreme cases, it may cause anemia, profuse bleeding, and kidney failure. E. coli is present in the feces of cattle, so contaminated beef is the most common cause of infection.
Salmonella — Found in the intestines of birds, reptiles and mammals, this nasty bacteria causes all kinds of gastrointestinal distress in humans, including abdominal cramps and diarrhea. It can also cause a fever, and in those with weakened immune systems, it may invade the bloodstream and bones. Any improperly handled foods may be contaminated by Salmonella, but in recent years eggs have often been the cause of human infection.
Campylobacter — Like Salmonella, this bacteria causes abdominal cramps and diarrhea, as well as a fever. Campylobacter is found in healthy birds, and it is normally present in raw poultry and other meat. It can also be contracted from streams and rivers or places where animals graze. It is the single most common worldwide cause of diarrhea. The juices of raw chicken are the most frequent cause of Campylobacter infection in our country.
Scoring a severe case of food poisoning is enough to provoke an obsessive-compulsive fear of germs. The most common bacterial culprits in foodborne illness are Salmonella, Campylobacter and a strain of E. coli referred to as O157:H7. The group of “Norwalk” viruses also contributes to a large number of food poisoning cases. Typical symptoms of gastrointestinal distress and fever appear within one to 48 hours after contracting the bug, and may take from three days to several weeks to clear up.
Bacteria reproduce by dividing, and when conditions are ideal, their numbers can multiply quickly, doubling with each generation. For example, E. coli can reproduce every 20 minutes–increasing by a hundredfold within a few hours!
What are the ideal conditions for bacteria to reproduce? A warm summer day is just perfect. Even food that has been properly cleaned and cooked can become dangerous if left out in the warm air for hours during a picnic, but poorly handled food is even more dangerous. A common scenario in cases of food poisoning is cutting uncooked vegetables on the same board where raw meat was prepared, without sanitizing the board. Undercooked meat, food that has been stored for too long, and unwashed vegetables are also frequent causes of contamination. The USDA recommends keeping cold food at or below 40 degrees Fahrenheit, and hot food at or above 140 degrees Fahrenheit. They also recommend not keeping food out for more than two hours. Additional information can be found by searching “safe food handling” at the USDA’s Food Safety and Inspection Service Web site: http://www.fsis.usda.gov/.