Can You Get Salmonella From Clean, Uncracked Eggs?

Yes, you can absolutely get Salmonella from eggs that are completely clean and uncracked ^[1]. While we often think of food contamination as something that happens on the outside—like dirt on a shell—certain types of Salmonella can actually infect the egg from the inside out before it is even laid ^[2].

How Salmonella Gets Inside a Perfect Egg

The most common strain of bacteria linked to egg outbreaks is Salmonella Enteritidis ^[1]. Unlike bacteria that contaminate the outside of an egg after it is laid, Salmonella Enteritidis can colonize a hen’s reproductive tract ^[1].

When a hen is infected, the bacteria can settle in her ovaries and oviduct ^[1]. As a new egg develops inside the bird, the bacteria are deposited directly into the egg white (albumen) or the yolk ^[2]. By the time the hard outer shell forms, the bacteria are already safely locked inside ^[1]. Medical professionals refer to this as vertical transmission (or transovarian transmission) because the infection is passed from the mother hen directly into the egg ^[1].

Why Washing and Inspecting Doesn’t Help

Many people mistakenly believe that buying pristine eggs, washing them thoroughly, or checking carefully for cracks will protect them from Salmonella. However, because the contamination is internal, surface-level cleaning is entirely ineffective at removing the risk ^[1].

In fact, washing eggs at home can actually make things worse. The eggshell has a natural protective coating and microscopic pores ^[3]. Washing the egg can damage this coating and push bacteria from the surface through the pores and into the egg ^[3][4]. Furthermore, research shows that once Salmonella Enteritidis is sealed inside the yolk, the environment can actually enhance the bacteria’s growth and make it more potent ^[2]. Inspecting for cracks is still a good practice to prevent outside germs from entering ^[3], but a perfectly intact shell offers zero protection against vertical transmission ^[1].

How to Protect Yourself

The only reliable way to neutralize Salmonella inside an egg is through proper temperature control and heat exposure. Salmonella Enteritidis exhibits specific adaptations to survive inside the egg ^[5], and some strains are highly heat-resistant ^[6][7].

To safely consume eggs and protect yourself and your family:

• Refrigerate immediately: Store eggs continuously in the refrigerator at or below 40°F (4°C) to prevent the bacteria from multiplying rapidly inside the egg ^[5].
• Cook thoroughly: Eggs must be cooked until both the yolk and the white are completely firm ^[6].
• Check the temperature: If you are cooking dishes that contain eggs (like casseroles or quiches), ensure the internal temperature reaches at least 160°F (71°C) ^[6].
• Avoid runny yolks: Sunny-side-up, soft-boiled, or poached eggs with runny yolks carry a higher risk of transmitting an active infection ^[6].
• Take extra care with vulnerable groups: It is absolutely critical that pregnant individuals, young children, older adults, and immunocompromised patients avoid raw or undercooked eggs, as they are at a much higher risk for severe, systemic infections ^[8][9].
• Use pasteurized eggs for raw recipes: If a recipe calls for raw or undercooked eggs (such as homemade Caesar dressing, mayonnaise, or cookie dough), use commercially pasteurized eggs ^[6]. Pasteurized eggs have been gently heated in their shells to a temperature that kills the bacteria without cooking the egg ^[7].