The Chicken or the Egg: Not What Came First, But What Will Make You Sick First
Which came first, the chicken or the egg? It doesn’t really matter, but can bacteria be transferred vertically from the hen to the egg and then infect humans? That’s the real question! The Centers for Disease Control and Prevention(CDC) estimate that salmonella and campylobacter infect 3.4 million Americans, sending 25,000 to hospitals and killing 500 people each year. Most cases derive from under cooked food and unsafe food handling.
Salmonella are bacteria that are commonly found in the intestinal tracts of animals. The handling of live baby chicks is one cause of multiple outbreaks of salmonellosis in small children. Avoiding contact with feces and carefully washing hands with soap and water after handling chicks and hens and avoiding hand-to-mouth contact can reduce this risk.
E. coli is usually found in the digestive system of healthy humans and animals. The pathogen is transmitted through fecal matter. If you stay away from the chicken poop you typically would not contract E.coli from a live bird, but rather the meat becomes infected through the slaughtering process.
Avian influenza is spread through the saliva, nasal secretions and feces of infected birds. The infection is not transmitted from hen to egg and chicks are not born with Avian Influenza. Most cases of bird flu infection in humans are the result of contact with infected poultry or contaminated surfaces.
Encephalitis is transmitted through the bite of an infected mosquito. For a chicken to become infected the bird must be exposed to infected mosquitoes and be bitten by an infected mosquito. There is no evidence that the virus is transmitted to the embryo in the egg or that new-hatched chicks transmit the virus to humans, or humans contract the condition from an infected hen.
The inside of an egg was once considered almost sterile. But, recent studies have shown that the bacterium Salmonella has been found inside a small number of eggs. If you eat an infected egg as long as it was cooked properly and served immediately you will not even know it. However if the egg was not cooked thoroughly or after preparation it was left at room temperature then the bacteria will grow and will lead to foodborne illness if consumed.
Most eggs are not contaminated from the hen, but can become contaminated through their porous shell. Bacteria if it is present in the soil or on hands can penetrate an old or cracked shell. The bacterium most likely gets in the egg white but is unable to grow due to lack of nutrients. As an egg ages, however the white thins and the yolk membrane weakens. This makes it possible for the bacteria to reach the nutrient dense yolk where it can grow if the egg is kept at warm temperatures. In some cases an egg is not contaminated when you buy it, but it can become contaminated from improper handling, such as with unclean hands and kitchen equipment.
Eggs must always be cooked thoroughly. Seventy-five percent of all cases of salmonella have been linked to foods containing raw or undercooked eggs. Be sure to cook eggs ’til the yolks are firm and never runny. Never use raw eggs in homemade salad dressings or mayonnaise, cookie dough or any other recipes.
Handling the Bird
- Wash your hands with soap and water immediately after touching live poultry or anything in the area where they live and roam.
- Adults should supervise children at all times around live poultry.
- Do not eat or drink in the area where the birds live or roam.
- Clean equipment and materials associated with raising poultry outside the house, not inside.
- Cook poultry thoroughly. Chicken should be cooked to an internal temperature of 165 degrees.
- Prevent raw chicken or its juices from touching other food.
- Wash your hands, all work surfaces and utensils with soap and water immediately after they have been in contact with raw meat or poultry.
- Store chicken at 40 degrees or below. Freeze it if you won’ use it for a couple of days.
- Don’ return cooked chicken to the same plate that had the raw chicken.
- Refrigerate or freeze leftovers within two hours of cooking.
- Wash all eggs that are not commercially raised.
- Refrigerate eggs at 45 degrees or below. Keep them in the coldest part of the refrigerator and not the door. The temperature fluctuates on the door and can lead to bacteria growth. Eggs can be stored for 3-5 weeks from the day they are refrigerated. Never freeze eggs in the shell.
- Prevent the spread of bacteria by starting with a clean area and clean utensils. Also watch out for cross-contamination.
- Cook eggs thoroughly to destroy bacteria. Make sure the yolks are firm and never runny. Be sure to cook foods that contain eggs thoroughly, such as French toast and quiches.
- At a party or outdoor setting, be sure to keep items with eggs out of the heat and ideally at a temperature below 40 degrees or above 140 degrees for hot foods. This will prevent bacteria from growing.
If you experience any symptoms of foodborne illness use iTriageHealth.com to help locate an urgent care or retail clinic near you.