Understanding the Real Risks: How likely is it to get Salmonella from raw eggs?

October 21, 2025 •

4 min read

The Centers for Disease Control and Prevention (CDC) estimates that, in the United States, roughly 1 in every 20,000 commercially sold eggs is contaminated with Salmonella, but this does not mean the risk is zero. Understanding precisely how likely is it to get Salmonella from raw eggs is critical for anyone consuming undercooked egg dishes or batters, as the consequences can be severe.

Quick Summary

This article explores the specific, albeit low, risk of bacterial contamination in uncooked eggs. It details essential hygiene practices, the importance of cooking eggs thoroughly, and offers safer alternatives for raw-egg recipes to protect against foodborne illness.

Key Points

Low, But Not Zero Risk: While the statistical probability of a single egg being contaminated with Salmonella is low (e.g., 1 in 20,000 in the U.S.), it is not a zero-risk food.
Internal and External Contamination: Salmonella can contaminate eggs either from inside an infected hen's reproductive tract (vertical) or from external fecal matter (horizontal).
Cooking is Key: The most effective way to prevent salmonellosis from eggs is to cook them thoroughly until both the yolk and white are firm.
Pasteurized Eggs for Raw Use: For dishes requiring raw or lightly cooked eggs, such as mayonnaise or salad dressing, always use pasteurized egg products.
High-Risk Individuals Should Avoid Raw Eggs: Young children, older adults, pregnant women, and those with compromised immune systems are most vulnerable and should never consume raw or undercooked eggs.
No Nutritional Advantage: There is no significant nutritional benefit to eating raw eggs over cooked ones; in fact, cooking improves protein and biotin absorption.
Proper Storage is Important: Refrigerating eggs at 40°F (4°C) or below and discarding any cracked eggs helps prevent bacterial growth and potential cross-contamination.

The Statistical Reality of Salmonella in Raw Eggs

While the 1 in 20,000 statistic for commercially sold eggs in the U.S. might sound reassuringly low, it's crucial to understand what this means in practical terms. For individuals, especially those in high-risk groups, a single contaminated egg is all it takes to become seriously ill. The prevalence of Salmonella can vary significantly by country and region, influenced by food safety regulations, vaccination programs for hens, and overall farm hygiene. Some regions have much higher reported rates of contamination, while others have significantly lower ones due to stricter controls.

It is a common misconception that eggs from local or backyard chickens are automatically safer. While some smaller-scale producers may have good practices, they often lack the stringent biosecurity controls of large commercial operations, which can sometimes result in higher contamination rates. The core takeaway is that a raw egg is never a zero-risk proposition, regardless of its source.

How Salmonella Contamination Occurs

Salmonella bacteria can contaminate an egg in two primary ways: vertically and horizontally.

Vertical Transmission

This occurs when the Salmonella bacteria infect the hen's reproductive organs. The bacteria can then contaminate the egg's contents (the yolk and white) before the shell is even formed. This is considered the more insidious type of contamination because it cannot be seen or smelled, and is unaffected by external cleaning or handling. A cooked egg is the only way to guarantee the destruction of bacteria from vertical transmission.

Horizontal Transmission

This is a more common route of contamination, where the bacteria are transferred to the outside of the eggshell from fecal matter after the egg has been laid. Chickens lay eggs through the same passage as they excrete waste, and bacteria can also spread from an unclean environment. For commercially sold eggs in many countries, washing and sanitizing processes significantly reduce this external risk. However, cracks in the shell, even hairline ones, can allow surface bacteria to penetrate and contaminate the interior.

Minimizing Your Risk: Safe Egg Handling and Preparation

To minimize your risk of getting Salmonella from eggs, follow these crucial food safety measures:

Buy Refrigerated Eggs: Always purchase eggs from a refrigerated case and ensure they remain at or below 40°F (4°C) at all times, including during transport home.
Inspect and Discard: Before purchasing, open the carton and check for any cracked or dirty eggs. Discard any eggs with a cracked shell.
Practice Good Hygiene: Wash your hands thoroughly with soap and hot water after handling raw eggs. Clean and sanitize all utensils, countertops, and cutting boards that have come into contact with raw eggs to prevent cross-contamination.
Cook Thoroughly: The most effective way to eliminate Salmonella is to cook eggs until both the yolk and the white are firm. Avoid runny yolks for maximum safety, especially for vulnerable individuals.
Consider Pasteurized Eggs: For recipes that call for raw or lightly cooked eggs, such as homemade mayonnaise, Caesar salad dressing, or eggnog, use pasteurized eggs or egg products. Pasteurization uses heat to kill harmful bacteria without cooking the egg.

Comparison of Raw vs. Cooked Eggs

For those who consume raw eggs for nutritional benefits, it's important to understand the lack of tangible advantages and the associated risk. The table below compares the key attributes.


Feature	Raw Eggs	Cooked Eggs
Protein Absorption	Can be less efficiently absorbed; some studies suggest around 50% absorption.	Protein is denatured and significantly more digestible; absorption rate can be up to 90%.
Biotin Bioavailability	Raw egg white contains avidin, a protein that binds to the B vitamin biotin, making it less available for absorption.	Cooking denatures avidin, allowing for full biotin absorption.
Salmonella Risk	Present and unavoidable risk, even if low probability.	Eliminated when cooked thoroughly, particularly to an internal temperature of 160°F (71°C).
Overall Nutrition	Contains the same vitamins and minerals as cooked eggs, but with reduced protein and biotin absorption.	Same nutrient profile as raw eggs but with improved digestibility and bioavailability of nutrients.

Who Is Most at Risk?

While everyone is susceptible to foodborne illness, certain groups face a higher risk of developing severe or life-threatening complications from Salmonella infection. These include:

Young Children and Infants: Their immune systems are still developing and are less equipped to fight off the infection.
Older Adults (65+): Age can weaken the immune system, making them more vulnerable to severe illness.
Pregnant Women: Infections can pose a risk to both the mother and the fetus, though eggs are generally safe when properly cooked.
Immunocompromised Individuals: People with conditions like HIV/AIDS, cancer, diabetes, or transplant recipients have a compromised ability to fight infection.

What to Do If You've Eaten Raw Eggs

If you have consumed raw or undercooked eggs and are concerned about Salmonella, be vigilant for symptoms, which typically appear 12 to 72 hours later and include diarrhea, fever, abdominal cramps, and vomiting. Most healthy individuals recover within 4 to 7 days without specific treatment, but severe dehydration is a risk. If symptoms are severe, bloody diarrhea occurs, or you belong to a high-risk group, contact a healthcare provider immediately.

Conclusion

The likelihood of any single raw egg being contaminated with Salmonella is low in regulated markets, but it is not a risk to be ignored. There is no nutritional advantage to eating raw eggs, and the simple act of cooking them thoroughly eliminates the risk of infection. By practicing diligent food safety, including proper handling, refrigeration, and cooking, you can safely enjoy eggs as part of a healthy diet. For any recipe calling for uncooked eggs, opting for a pasteurized product is the safest alternative for all consumers, especially those in vulnerable populations.

FoodSafety.gov offers additional guidance on egg safety and handling for consumers.

Frequently Asked Questions

No, it is never completely safe to eat raw eggs, even from a well-regulated store. While the likelihood of contamination is low due to safety measures, a small risk of Salmonella infection remains.

Symptoms usually include diarrhea, fever, abdominal cramps, and vomiting. These typically appear 12 to 72 hours after exposure and can last for 4 to 7 days.

Yes, pasteurized eggs are the safest option for any recipe that uses raw or lightly cooked eggs, such as hollandaise sauce, Caesar dressing, or tiramisu.

Not necessarily. While some people prefer farm eggs, they may not undergo the same strict washing and safety controls as commercial eggs, meaning their contamination risk can sometimes be higher or less predictable.

No. Cooking an egg actually increases the digestibility and absorption of its protein. Some research indicates that only about 50% of the protein in raw eggs is absorbed, compared to nearly 90% in cooked eggs.

No, you cannot. An egg contaminated with Salmonella will look and smell normal. The bacteria can be inside the egg, making it undetectable to the naked eye.

Always store eggs in their original carton in the coldest part of the refrigerator, not the door. The temperature should be maintained at 40°F (4°C) or colder to inhibit bacterial growth.

Cross-contamination is the transfer of bacteria from one surface to another. To prevent it, wash your hands and all surfaces that touch raw eggs, and use separate utensils and cutting boards for preparing foods.