A supermarket shelf full of eggs. Eggs may contain salmonella.

An additional 12 people have contracted salmonella from contaminated eggs produced by Rose Acre Farms, according to the Centers for Disease Control and Prevention—bringing the total to 35. Eleven people have been hospitalized in the outbreak, and the eggs may have reached consumers in nine states.

In March, a salmonella outbreak linked to kratom supplements also sickened dozens of people.

More On Food Safety

These kinds of widespread outbreaks of salmonella tend to grab national headlines for good reason, says Matthew Zahn, M.D., chair of the Infectious Diseases Society of America’s public health committee. Salmonella, a type of bacteria, is the second most common cause of food poisoning in the U.S., affecting about 1.2 million people every year and causing 450 deaths, according to the CDC.

This year alone, there have been six multistate salmonella outbreaks. “At the same time,” Zahn says, “the vast majority of salmonella cases we see are not related to national outbreaks.”

Plenty of cases don’t garner national attention because they may be related to smaller, in-state outbreaks or because people may have a stomach bug but not realize it’s salmonella. 

Most people recover from these infections, but the bacteria poses a greater threat to more vulnerable people, such as children younger than 5 and pregnant women. Here’s what you need to know about this most recent outbreak, and how to recognize and handle a case of salmonella.

If You Live Here, Check Your Eggs

The potentially contaminated Rose Acre Farms eggs, which came from a farm in North Carolina, were sold to grocery stores and restaurants in Colorado, Florida, New Jersey, New York, North Carolina, Pennsylvania, South Carolina, Virginia, and West Virginia.

Consumers should still be on the lookout for these products. If you’ve purchased eggs in one of these states recently, check the carton. First, look for the plant number. If you see P-1065, look for another three-digit number, which is the date code. If the number is within the range 011 to 102, throw the eggs away.

Eggs with the plant number P-1359D, a date code of 048A or 049A, and a “best by” date of April 2 or 3, should also be thrown away.

(You can also find a list of recalled products at the Food and Drug Administration’s website.)

The CDC also recommends that you clean the shelf or drawer in which you kept the eggs with warm, soapy water.

Contaminated Eggs and Beyond

Eggs can be contaminated by salmonella in two ways, says Elizabeth Hohmann, M.D., associate professor of infectious diseases and medicine at Harvard Medical School and Massachusetts General Hospital. Salmonella can cling to the outside of egg shells after the shells have been contaminated by chicken droppings. The Department of Agriculture requires producers to clean the shells of eggs, but bacteria can still be there.

Salmonella can also be found inside the egg, even if it’s unbroken. “The rare egg gets salmonella passed to it in the chicken’s body,” Hohmann says.

Eggs aren’t the only place salmonella lurks, though. “In the past, salmonella has shown up in some unexpected places, such as dietary supplementspeanut butter, and dried coconut. But some of the most common food sources of the bacteria are still contaminated poultry, meat, and eggs,” says Sana Mujahid, Ph.D., manager of food safety research and testing at CR. “Outbreaks such as these are a good reminder that proper food safety strategies—cooking raw meat and eggs thoroughly, preventing cross-contamination in the kitchen, and washing hands regularly—can significantly reduce your risk of contracting salmonella.”

Cooked eggs are safer than raw or runny eggs. If you’re making a recipe that calls for raw or lightly cooked eggs, the CDC recommends using ones that have been pasteurized, which kills the bacteria.

Meats should be cooked as well, especially poultry, which you should bring to 165° F before eating.

You should also wash your hands and any cooking utensils that come into contact with raw eggs or meat.

And while most people catch salmonella from food, it’s also possible to spread it from person to person. “Obviously, frequent hand-washing is important,” Zahn says. And if you’re sick, take a break from cooking; you should avoid preparing any food for other people.

The Symptoms of Salmonella

If you start to feel sick, know this: Symptoms of salmonella typically take 12 to 72 hours to hit—so it’s unlikely that what you just ate 30 minutes before is responsible.

The classic salmonella symptom is diarrhea, often accompanied by fever and abdominal pain, Zahn says. Vomiting can occur, though it’s less common with salmonella than with other gastrointestinal infections, such as norovirus.

Symptoms usually last for a few days, though they can continue for a week or more. (Bowel function may be irregular for up to several months after infection, however, the CDC says.)

As with any gastrointestinal infection, staying hydrated is key to preventing complications. Drink plenty of water, juice, broth, or other caffeine-free, nonalcoholic fluids.

Most people don’t need other treatment and will get better on their own. However, children younger than 5, older adults, pregnant women, and people with compromised immune systems are more likely to get sick from salmonella and are at greater risk for severe complications.

Watch for Serious Illness

Severe dehydration is one complication that can occur. Another is that the infection can sometimes spread from the intestines to the bloodstream, where it can affect other parts of the body; this can be life-threatening.

Contact your doctor if you have a fever of 101.5° F or higher or bloody diarrhea. If you experience severe dehydration, or “changes in your level of consciousness,” Zahn says—meaning you’re fading in and out or feeling confused or dizzy—see a doctor immediately.

If you or a loved one is in one of the high-risk groups, however, having diarrhea with fever is of enough concern on its own that you should see a doctor, Zahn says.

Editor’s note: This article has been updated to reflect additional information about recalled products from the CDC.