According to the Centers for Disease Control and Prevention, 73,000 Americans develop E. coli infections each year. The strain of the bacteria that causes most of the infections is E. coli 0157:H7.

Most people get sick after eating undercooked beef.

What it is: Escherichia coli (E. coli) is a bacteria. Of hundreds of strains, several can cause illness.
   Common sources: Undercooked beef, cattle and other animals, unpasteurized milk and juice, unwashed fruits and vegetables, salami, an infected person, swimming in or drinking sewage-contaminated water.
   Who is most susceptible: Children younger than 5, the elderly and people with compromised immune systems.
   Symptoms: Watery or bloody diarrhea, fever, abdominal cramps, nausea, vomiting. Symptoms may last five to 10 days.
   What can happen: Kidney failure, neurological impairment, surgical removal of part of the bowel, death.
   Treatment: Most people with mild to moderate symptoms recover without treatment. Those who develop serious complications usually require hospitalization.
   
   Keep bacteria at bay:
   l Wash hands with soap and water after contact with barnyard or zoo animals or using the toilet or changing diapers. Hand sanitizers are a second choice.
   
Do not let little children who are likely to put their hands in their mouths touch animals.
Do not eat or prepare food until you have washed your hands.
   
Thoroughly wash raw foods before eating.
   
Cook meats completely.

New petting zoo rules: Reach through fence

RALEIGH - The days are gone for mingling with goats and sheep and walking through their bedding and manure at the state fair.

The Department of Agriculture announced new guidelines Thursday for petting zoos and animal exhibits that will require visitors to reach through fences to pet the animals and carefully wash their hands afterward.

The rules are in response to last year's outbreak of the E. coli bacteria that sickened more than 100 people -- mostly children -- who strolled through a petting zoo at the N.C. State Fair in Raleigh.

E. coli doesn't sicken animals, but it can kill humans. The bacteria is usually passed on when people make contact with the manure of sheep, goats, cows and deer.

Before, children would sit down in the animal bedding, drop things in the bedding and then put them in their mouths, said Mary Ann McBride, a department veterinarian who helped develop the new guidelines.

"There's no way to completely eliminate the risk. But this is as safe as we can be," she said.

The NC State Agriculture Department says visitors can no longer walk into animal pens.  Instead, you'll need to stay an arms length from the livestock.  Visitors can reach through fences to pet the animals, but officials are strongly urging everyone to wash their hands afterward.  The new rules stem from last year's outbreak of e-coli bacteria.  More than a hundred people, mostly children became sick visiting the petting zoo.

TALLAHASSEE, Fla. - An outbreak of E. coli bacteria in central Florida that has caused kidney disease in several people has been definitively linked to animals from petting zoos at three fairs, state officials said Friday.

Epidemiologists matched DNA from E. coli bacteria in six animals - two goats, two sheep and two cows

A 2003 study on the prevalence of E. coli O157:H7 in livestock at 29 county and 3 large state agricultural fairs in the United States found that E. coli O157:H7 could be isolated from 13.8% of beef cattle, 5.9% of dairy cattle, 3.6% of pigs, 5.2% of sheep, and 2.8% of goats. Over seven percent of pest fly pools also tested positive for E. coli O157:H7 (Keene et al, 2003). It is common knowledge that the main source of E. coli O157:H7 are ruminants. Studies have shown that more than 80% of herds of cattle carry E. coli O157:H7.  A large number of other animals, such as sheep and goats, also carry this pathogen.

E. coli being transmitted by direct contact with farm animals has only been documented a few times, all since 1996. It's usually linked to bad food.