Can you get sick from eating raw eggs?

In this article, we will answer the question “Can you get sick from eating raw eggs?”, and where does Salmonella come from?

Can you get sick from eating raw eggs?

Yes, you can get sick from eating raw eggs. Raw eggs are often contaminated with Salmonella. When ingested, salmonella can lead to food poisoning. More on this in the article below. 

Salmonellosis is the second most common zoonosis in humans after campylobacteriosis with 52,702 confirmed human cases in 2020. In Europe Salmonella was the most frequently encountered foodborne pathogen in humans accounting for 22.5% (694 salmonellosis outbreaks) of the total foodborne outbreaks and causing the highest number of diseases (3,686; 18.41% of all the outbreak-related diseases) and hospitalisations (1).

How can I reduce my chance of getting a Salmonella infection? (2,3,4)

1. Only buy refrigerated eggs and make sure they are continuously refrigerated at a steady temperature of 40°F (4°C) or colder.
2. Get rid of cracked or dirty eggs.
3. Prefer using pasteurized eggs or egg products over unpasteurized eggs or products made with unpasteurized eggs.
4. Cook the eggs to a fir texture. Make sure that the eggs reach an internal safe temperature of 160°F (71°C) or hotter.
5. Do not buy foods that are made with unpasteurized raw eggs or lightly cooked eggs such as Hollandaise sauce, Caesar salad dressing, and Temasu, etc.
6. Eggs or dishes made with eggs should be refrigerated within 2 hours of cooking. Refrigerate within one hour if the temperature is 90°F or hotter.
7. Wash your hands and food-contact surfaces such as countertops, utensils, dishes, and cutting boards, before and after handling eggs. Use soap to kill bacteria.
8. Avoid taste-checking raw dough or batter made using unpasteurized eggs.

The contamination of eggs with Salmonella during the production process is a complex issue, influenced by many variables including flock size, flock age, stress, feed, vaccination, and cleaning routines. Pasteurization and irradiation were identified as the only certain methods for controlling Salmonella and are essential for the protection of high risk groups, whereas control of temperature and pH were identified as potential control methods to minimize the risk for foods containing raw eggs (3).

Salmonella affects different people differently 

Some people are at a higher risk of contracting the Salmonella infection and suffering extreme symptoms. These people are categorized as immunocompromised and include Adults older than 65 years, children younger than 5 years, and people with weakened immune systems, such as those with HIV/AIDS, diabetes, or an organ transplant.

The most common symptoms of Salmonella infection are diarrhea, vomiting, fever, and abdominal cramps. These symptoms should be gone within 4-7 days after eating the contaminated food. Reach out to your doctor if the symptoms persist beyond a week or get progressively worse.

In general the incubation period depends on the immune system of the host and the bacterial inoculum size. Infection can cause acute severe diarrhea or chronic and prolonged diarrhea, which can result in the disturbance of fluid and electrolyte balances. Salmonella infection can be severe, invasive and recurrent in patients with human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS), resulting in up to 47% mortality (5).

Where does Salmonella come from?

Internal contamination of eggs with Salmonella occurs in the reproductive organs during egg formation. Salmonella have been demonstrated to have the ability to colonize the reproductive tract of hens (3).

The feces of animals and sick animals are the habitats of Salmonella. The incidence of Salmonella contamination is higher in poultry since the hens are kept in extremely unhygienic and congested places. Salmonella easily transfers from contaminated feces to healthy birds and eggs.

Salmonella lives on the eggshell and penetrates the shell when the eggs are mishandled during transport or cracking. However, there is no 100% guarantee that the inside of the egg is sterile at all times. 

Nutrition 

The nutrition value of an egg varies with its preparation method. The following table shows the nutritional value of a large, whole, and a raw egg, according to the US Department of Agriculture.

Egg yolk is packed with essential amino acids, fatty acids, vitamins and other micronutrients such as choline. One large egg provides approximately 27% of the daily value of choline. It has been reported that hard-boiled eggs represent the second major source of choline after beef liver and the first source of choline in the US diet (6).

How to tell if the eggs have spoiled?

Let your senses guide you. 

1. Rotten eggs give off a foul smell that does not go unnoticed. Therefore, throw away all the smelly eggs without a second thought.
2. If the eggshells feel tacky upon touching and appear slimy or dusty, throw them out because it is a clear indication of bacterial and fungal invasion.

3. If the eggshell is damaged, it is highly likely that the egg is contaminated. It is better to discard it.
4. Fresh eggs have clear and firm whites, and an outline of fairly well defined      yolk, that is practically free from defects, free form odors. Spoiled eggs have weak and watery whites or may have small blood and meat spots present, the yolk has outline plainly visible enlarged and flattened, may have clearly visible germ development and have other serious defects (7).

How to store eggs safely?

• Prompt refrigeration to temperatures capable of restricting microbial growth has been recommended as an approach to reducing the likelihood that contaminated eggs will transmit S. Enteritidis to humans (4).
• Although washing eggs is not recommended by the USDA, washing eggs is a practice in many countries. There are advantages by washing eggs: the reduction of microbial load on the shell surface, minimizing the risk associated with the presence of foodborne pathogens, especially Salmonella spp. Eggs must be washed following correct procedures of safety (4).
• Keep eggs in a cool and dark place in the pantry. Do not expose yourself to direct sunlight or moisture.
• Keep washed eggs in the refrigerator at 4°C or below.
• Keep an eye on the expiration dates. Do not use eggs past the expiry.

Is freezing eggs a good choice?

Freezing eggs is not recommended. Freezing temperatures damage the quality of an egg to large extents. If an egg is frozen intact, the egg and yolk will expand upon freezing, thus, breaking the eggshell. Use frozen eggs within 1 year. Eggs should not be frozen in their shells. To freeze whole eggs, beat yolks and whites together. Egg whites can also be frozen by themselves.

Moreover, the yolk inside it will solidify and look as if it has been boiled. The egg white will not be able to incorporate air in your baked goods as it will lose its texture as a result of protein denaturation.

So If you do not want to waste your money by freezing eggs then whisk it properly, put the mixture in a freezer bag, and store it for up to 4 months.

If you wish to store your raw egg white and yolk separately, you can save their quality by whisking your egg white or yolk with sugar, salt, or corn syrup depending on their end-use (8).

Other FAQs about Eggs that you may be interested in.

What can I use instead of eggs?

What can I substitute for eggs in cakes?

Can you freeze an omelet?

Conclusion 

In this article, we answered the question “Can you get sick from eating raw eggs?”, and where does Salmonella come from?

References 

1. Mihalache, Octavian Augustin, Paula Teixeira, and Anca Ioana Nicolau. Raw-egg based-foods consumption and food handling practices: A recipe for foodborne diseases among Romanian and Portuguese consumers. Food Control, 2022, 139, 109046.
2. Shell eggs from farm to table. US Department of Agriculture. 2019.
3. Whiley, Harriet, and Kirstin Ross. Salmonella and eggs: from production to plate. Int j environ res public health, 2015, 12, 2543-2556.
4. Galiş, Anca M., et al. Control of Salmonella contamination of shell eggs—preharvest and postharvest methods: a review. Comprehen Rev Food Sci Food Safe, 2013, 12, 155-182.
5. Onwuezobe, Ifeanyi A., Philip O. Oshun, and Chibuzo C. Odigwe. Antimicrobials for treating symptomatic non‐typhoidal Salmonella infection. Cochrane Database of Systematic Reviews 2012,11.
6. Réhault-Godbert, Sophie, Nicolas Guyot, and Yves Nys. The golden egg: nutritional value, bioactivities, and emerging benefits for human health. Nutrients, 2019, 11, 684.
7. Zeidler, G. 2002. Shell Egg Quality and Preservation. In: Bell, D.D., Weaver, W.D. (eds) Commercial Chicken Meat and Egg Production. Springer, Boston, MA. 
8. Haley-Hadley, C. Freezing eggs to keep them longer. 2022. University of Arkansas.