Chicken eggs are probably the least well treated protein in the kitchen and food industry as a whole. It is the only protein that is commonly left out at ambient temperature in the retail stores.
Salmonella is synonymous with chicken, eggs and Salmonella is one of the most common food poisoning bacteria throughout the world. So why are our eggs handled in this way?
S.enteritidis is the disease causing species that causes salmonellosis. S.enteritidis is a gram-negative, rod-shaped bacteria.
S.enteritidis species are like E.coli and can be considered the big brother of Salmonella. They are similar because they cause infection in the same ways. Especially via the faecal-oral route. Salmonella is also thought to be one of the major causes of traveller’s diarrhoea.
E.coli is tougher than Salmonella because they can survive harsher conditions. Such as higher temperatures, lower moisture and higher salt contents.
Food microbiologists say that if there is E.coli present you are likely to have Salmonella as well. But this does not mean that we shouldn’t be concerned about Salmonella. In fact, this bacteria is most infamous for contamination of eggs rather than red meats and in the gut.
Chocolate has also had cases of contaminated with S.enteritidis. In general, we expect E.coli to be present in red meats, and Salmonella in chicken. Yet, E.coli is also present in chicken as well as fruits and vegetables. So focusing on eradicating E.coli will usually address Salmonella as well.
Salmonellosis is likely one of the most common forms of food poisoning throughout the world.
Eggs need to be pasteurised
Eggs are pasteurised in order to reduce the risk of causing food poisoning, especially Salmonella Enteritidis bacteria and Avian Influenza virus that may be present on or inside the eggs. Because eggs have a protective shell, once pasteurised, eggs are then considered free from pathogenic bacteria.
Eggs are laid in an environment where hens’ excretion and airborne bacteria may be present. This means that bacteria can be present on the eggshells. Bacteria from the environment can enter the pores on the eggshell if the natural protective layer if breached.
Bacteria can also be found inside an egg as bacteria can be passed on to the egg during egg formation if the hen laying the egg is infected by Salmonella Enteritidis.
Yet, it is true that if the pasteurisation process is not done correctly, harmful bacteria can still survive. This is when leaving eggs out at ambient temperature creates the ideal environment for bacteria such as Salmonella to grow to high numbers.
Salmonella Food Poisoning
The above chart shows us that in the USA alone 23000 cases of Salmonella poisoning takes place each year. Of those an estimated 8000 cases are egg-related. Clearly there is a relationship between eggs and Salmonella.
We also know that from the above, there are concerns about how effective eggs are handled and pasteurised. So, how do we prevent contamination in the kitchen?
There are 4 key steps in the process to egg food safety:
Avoid cracked and dirty eggs
Cook eggs until they are hot all the way through
Avoid uncooked food that contains raw eggs
- Refrigerate raw eggs and egg products at 4°C (39° F)
Recent Outbreak Data for Eggs And Salmonella
Salmonella outbreak from suspected eggs – November 2018 South Africa
Salmonella bacteria, most likely from contaminated eggs, has put at least 30 people in the greater Durban area in hospital, and sickened many more.Social media reports posted by people who’d contracted salmonellosis after eating at the upmarket Old Town Italy restaurant in Umhlanga – mostly meals including hollandaise sauce – raised the alarm, but the outbreak of the past few weeks goes far beyond one restaurant.
Salmonella outbreak from eggs – September 2018 USA
A multi-state salmonella outbreak linked to eggs from an Alabama farm has expanded with 24 more people ill in five more states, the Centers for Disease Control and Prevention says. Gravel Ridge Farms in Cullman, Alabama, recalled its cage-free large eggs last month saying the eggs could be contaminated. At the time, 14 people had been infected with the strain of Salmonella Enteritidis in Tennessee and Alabama. Since then, the CDC has identified another two dozen illnesses from June 17 to Aug. 16, with some occurring in Colorado, Iowa, Kentucky, Ohio and Montana. Ten people have been hospitalised; no deaths have been reported, the CDC says.
Salmonella outbreak from eggs – June 2018 USA
As of June 14, 2018, 73 people infected with the outbreak strain of Salmonella Mbandaka have been reported from 31 states. A list of the states and the number of cases in each can be found on the Case Count Map page. Illnesses started on dates from March 3, 2018, to May 28, 2018. Ill people range in age from less than one year to 87, with a median age of 58. Sixty-five percent are female. Out of 55 people with information available, 24 (44%) have been hospitalized. No deaths have been reported.
Illness from Salmonella
In most cases, illness lasts 4–7 days and people recover without antibiotic treatment. Symptoms include:
- Abdominal cramps.
Symptoms typically appear 6 to 48 hours after eating a contaminated food, though this period is sometimes much longer. Some people can have diarrhoea many times a day for several days and the sick person may need to be hospitalised.
Guidelines recommended by the FDA
Preparing eggs safely
Wash hands, utensils, equipment, and work surfaces with hot, soapy water before and after they come in contact with raw eggs and raw egg-containing foods.
- Cook eggs until both the yolk and the whites are firm. Scrambled eggs should not be runny.
- Casseroles and other dishes containing eggs should be cooked to 70° C (160° F). Use a food thermometer to be sure.
- For recipes that call for eggs that are raw or undercooked when the dish is served — like Caesar salad dressing and homemade ice cream — use either shell eggs that have been treated to destroy Salmonella, by pasteurization or another approved method, or pasteurized egg products.
Serving eggs safely
Follow these serving guidelines for eggs and egg dishes.
- Serve cooked eggs (such as hard-boiled eggs and fried eggs) and egg-containing foods (such as quiches and soufflés) immediately after cooking. Cooked eggs and egg dishes may be refrigerated for serving later but should be thoroughly reheated to 165° F before serving.
- Never leave cooked eggs or egg dishes out of the refrigerator for more than 2 hours or for more than 1 hour when temperatures are above 32° C (90° F). Bacteria that can cause illness to grow quickly at warm temperatures.
- For party planning, keep hot egg dishes hot and cold egg dishes cold:
- Keep egg dishes refrigerated until time to serve.
- Serve small platters of reheated egg dishes at a time to ensure the food stays at the proper temperature. Replenish as needed, or at least every 2 hours.
- Keep cold egg dishes on ice if they are going to stay out longer than 2 hours.
Transporting eggs safely
- For picnics, pack cooked eggs and egg dishes in an insulated cooler with enough ice or frozen gel packs to keep them cold. Transport the cooler in the passenger compartment of the car, not in the much warmer trunk. At the picnic area, put the cooler in the shade if possible and keep the lid closed as much as you can.
- For school or work, pack cooked eggs with a small frozen gel pack or a frozen juice box.