For those of you who have chickens, you may be asking, “How safe are MY eggs from Salmonella contamination?”
The good news is, they are likely VERY safe.
Salmonella are bacteria that live in human and animal intestinal tracts. The bacteria can pass in fecal matter and so may be found in soil, water, and other matter that has come into contact with fecal matter.
So how do the bacteria get into eggs? There are two ways this might happen:
1) Chicken poop gets on the shell of the egg. The bacteria pass through the pores and proliferate inside the egg.
2) An industrial egg-laying hen whose ovaries are contaminated with salmonella bacteria passes the bacteria along in the egg-formation process.
Solutions are fairly simple.
1) Give your hens adequate space and good living conditions. This includes clean food and water daily. Hens in poor living conditions, like battery-caged layers, are more susceptible to illness (like salmonella) due to overcrowded, stressful living conditions. In your backyard coop, one nest for every four hens is adequate.
2) Keep your nest boxes free of fecal matter. Wood shavings are good for this, because the poop can easily be scooped out in clumps, much like clumping kitty litter.
3) Collect your eggs daily and refrigerate them right away. Industrial eggs have many stops: candling, sizing, packaging, shipping, shipping again, shelf stocking. Along the way temperatures can fluctuate, leading to bacterial growth. Keeping your eggs refrigerated will prevent this.
4) Wash your eggs only when you are ready to use them. When a hen lays an egg, she secretes a wet covering that seals off the pores from pathogens. If you see a freshly laid egg, you will notice that it looks wet and then quickly dries. This is called the cuticle or bloom. Keep this coating intact until you are ready to use the egg. Brush or sand off any foreign material that is on the eggshell.
5) Cook eggs completely. Cooking eggs to 160 degrees will prevent illness.
If your hens are contaminated with salmonella, you will most likely have built up immunity to the particular strain they carry.
(Sources: Damerow, Gail. “Backyard Chicken Eggs Are Safe,” and Jansen Matthews, Lisa. “Safe Egg Handling,” both in Backyard Poultry, October/November 2010, 6.)