BAKERSFIELD, Calif. -- "It's extremely rare to have a salmonella outbreak in the egg industry. In fact in California we haven't had a Salmonella Enteritidis associated outbreak in more than 10 years," said Veterinarian Nancy Reimers.

Even more rare is the current species of salmonella. "Salmonella Enteritidis is very rare. I've heard people encounter a Salmonella Enteritidis positive egg once every 84 years," said Reimers.

Yet two farms in the Midwest have tested positive for Salmonella Entertidis from unsanitary conditions. "Salmonella can be spread through feed, through chicks coming onto the farm. It can be spread by visitors who've been to other poultry facilities. It can be spread by rodents and flies," said Reimers.

Reimers said the bacteria starts in the gastro intestinal tract of the hen and spreads to its ovaries where it infects the eggs. That is why egg farms like Farmer John Eggs is constantly working to avoid salmonella.

Reimers conducts monthly checkups of Farmer Johns chickens and their eggs. Blood is drawn and feces swabbed to test for salmonella. All areas around the hen houses are kept clear of brush and vegetation to deter rodents. "Rodents don't like to cross large distances. We also go through and put out bait on a regular basis so rodents are euthanized," said Reimers.

Visitors are also kept to strict standards and requested to wear head to toe protective jumpsuits to avoid spreading bacteria on their clothes to the chickens.

"Reading about how they did things in the Midwest, I'm just absolutely amazed that those farms with salmonella even put out any eggs," said Farmer John Eggs owner John Lewis. In California, health and safety regulations are extremely strict and enforcement is even more strict. "I've got federal inspectors, state inspectors and county inspectors coming all the time," said Lewis. Their options for him: be 100 percent salmonella free or shut down. "I think it's a matter of economic life or death," said Lewis.