You can get salmonella by eating contaminated food, touching infected animals, swallowing contaminated water, or picking up the bacteria from an infected person. In the United States, salmonella causes an estimated 1.28 million illnesses every year, making it one of the most common foodborne infections and the leading cause of death among foodborne pathogens, responsible for roughly 238 deaths annually.
Contaminated Food Is the Most Common Source
Most salmonella infections start with food. Poultry is the biggest culprit: chickens naturally carry the bacteria in their intestines, and raw or undercooked chicken can easily pass it to you. Eggs are another well-known source, and the contamination doesn’t always come from the outside of the shell. Salmonella can get inside an egg while it’s still forming inside the chicken, before the shell even develops. That means a perfectly clean-looking egg can still harbor the bacteria internally.
Fruits and vegetables are less obvious carriers, but they cause outbreaks regularly. When irrigation water is contaminated with salmonella, it can transfer the bacteria to produce before or after harvest. Sprouts, leafy greens, melons, and tomatoes have all been linked to outbreaks over the years. Washing produce helps, but bacteria that entered through contaminated irrigation water can be difficult to remove completely.
Cross-contamination in the kitchen is another major pathway. If you cut raw chicken on a cutting board and then chop vegetables on the same surface, the bacteria transfer easily. Unwashed hands and shared knives do the same thing. Salmonella can survive on kitchen sponges for up to 16 days at room temperature, so even cleaning tools can become a source of ongoing contamination if they aren’t sanitized regularly.
Reptiles, Poultry, and Other Animals
Touching animals is the second most common way people pick up salmonella, and it doesn’t require the animal to look sick. Reptiles, including lizards, snakes, and turtles, along with amphibians like frogs and salamanders, frequently carry salmonella in their intestines without showing any symptoms. They shed the bacteria into their surroundings through their droppings, contaminating tank surfaces, bedding, and anything nearby.
Specific types of reptiles have been linked to specific strains. Bearded dragons, turtles, and snakes each tend to carry different salmonella variants. Stress, overcrowding, and poor habitat conditions increase the amount of bacteria these animals shed, which is why pet stores and home setups with inadequate care pose higher risks. Live poultry, including backyard chickens and ducklings, are also frequent sources. You don’t need to handle the animal directly. Touching a cage, terrarium, or any surface the animal has contacted is enough.
The practical takeaway: always wash your hands thoroughly after handling reptiles, amphibians, or live poultry, and keep these animals away from kitchen surfaces and areas where food is prepared.
Contaminated Water
Salmonella can contaminate drinking water, recreational water like lakes and pools, and irrigation water used to grow food. Untreated or improperly treated water sources carry the most risk. Swimming in a lake or pond where animal waste has entered the water, or accidentally swallowing pool water that’s been contaminated by a sick swimmer, can both lead to infection. Municipal water supplies are generally safe because of chlorine treatment, but private wells and natural water sources don’t have that protection.
Person-to-Person Spread
Salmonella spreads between people through what’s known as the fecal-oral route. In plain terms, if someone with an active infection doesn’t wash their hands well after using the bathroom, they can transfer bacteria to surfaces, shared objects, or food they prepare. This is especially relevant in households with young children in diapers, or in settings like daycare centers and nursing homes where caregivers handle hygiene tasks for others.
How Much Bacteria It Takes
The number of salmonella cells needed to make you sick varies widely, from as few as 1,000 organisms to over a billion. That range depends on the specific strain and on your own vulnerability. Young children, older adults, pregnant people, and anyone with a weakened immune system can get sick from a much smaller dose. For healthy adults, a larger dose is typically needed, but heavily contaminated foods like raw poultry or improperly stored leftovers can easily deliver those numbers.
What Happens After Exposure
Symptoms usually appear 6 hours to 6 days after you’re exposed. Most people develop diarrhea, stomach cramps, and fever that last 4 to 7 days. The illness resolves on its own for most healthy adults, but severe cases can lead to hospitalization. Of the 1.28 million annual infections in the U.S., roughly 12,500 result in hospital stays.
Cooking Temperatures That Kill Salmonella
Heat is the most reliable way to eliminate salmonella from food. The specific internal temperatures you need depend on the food:
- Whole and ground poultry: 165°F (74°C)
- Ground meat and sausage (beef, pork): 160°F (71°C)
- Egg dishes like quiche or frittata: 160°F (71°C)
- Eggs cooked on their own: cook until both the yolk and white are firm
A food thermometer is the only reliable way to verify these temperatures. Color and texture aren’t accurate indicators, particularly with poultry. Beyond cooking, keeping raw meats separated from ready-to-eat foods during storage and preparation, washing hands for at least 20 seconds after handling raw animal products, and sanitizing cutting boards and utensils after each use are the most effective ways to prevent cross-contamination at home.