CDC Says a Salmonella Outbreak Has Sickened 125 People in 15 States—But No One Knows What's Causing It

At least 125 people across 15 states have fallen ill after becoming infected with Salmonella Newport, the Centers for Disease Control and Prevention (CDC) reported on Tuesday—but officials have yet to determine the source of the outbreak.

Salmonella infection (salmonellosis) is a common disease, caused by bacteria which typically live in animal and human intestines that are shed through feces. The bacteria most frequently infects humans through contaminated water or food. The "Newport" portion of Salmonella Newport is the serotype (strain) name for this species of Salmonella—and this isn't the first time it has emerged as a pathogen in both animals and humans throughout the US. According to an article published in the Journal of Clinical Biology in 2003, Salmonella Newport was already "of increasing concern," even then, as the third leading cause of human salmonellosis.

On July 10, the CDC's PulseNet, a national laboratory network that connects foodborne illness cases to detect outbreaks, identified 13 Salmonella Newport infections in three states. Over the next 10 days, the outbreak grew rapidly—to 125 infections in 15 states: California, Illinois, Iowa, Michigan, Missouri, Minnesota, Montana, North Carolina, Ohio, Oregon, Tennessee, Utah, Washington, Wisconsin, and Wyoming. As of Wednesday, Oregon, Utah, and Michigan have the most reported cases. The infected people range in age from 2 to 92, and 24 of them have been hospitalized.

A data analysis method called whole genome sequencing (WGS) was used to give investigators detailed information about the bacteria that was causing sickness. It showed that bacteria isolated from sick people were closely related genetically, meaning a shared, common source of infection is likely. However, in this case, the CDC hasn't yet identified the source of the bacteria.

"The original source of the outbreak can likely be linked to various touchpoints," virologist Tamika Sims, PhD, director of food technology communications at the International Food Information Council, tells Health. "If a food is the source, it may go to various restaurants or stores. If a food processing facility is the origin and they produce multiple foods, [there] may be different sources. This is why food traceability techniques for tracking food and ingredient resources are very important."

According to the CDC, it is taking around two to four weeks in this investigation for an illness to be diagnosed, confirmed, reported to state officials, and then reported to federal officials. This means the national tally is likely to rise as more information becomes available. There's currently no need to panic, but it's always important to be aware of the symptoms and prevention techniques for a Salmonella infection—here's what you need to know.

What are the symptoms of Salmonella?

If you have Salmonella, you can expect diarrhea, fever, and stomach cramps. Some people may also have nausea, vomiting, or a headache. Typically, symptoms start within six hours to six days after ingesting the contaminated substance, and they last for four to seven days.

The CDC recommends getting medical attention if you have diarrhea and a fever higher than 102 degrees Fahrenheit, diarrhea for more than three days that is not improving, bloody stools, prolonged vomiting that prevents you from keeping liquids down, or signs of dehydration, such as producing very little urine, a dry mouth and throat, or dizziness when standing up.

Is Salmonella easy to treat?

A Salmonella infection isn't pleasant, but it's rarely life-threatening and doesn't usually require any specific treatment. In fact, Sims says most people can recover without antibiotics. If you have diarrhea, drinking a lot of water and other fluids should help. If diarrhea is severe, your doctor may suggest a rehydration liquid like Pedialyte or an antidiarrheal medication like loperamide (Imodium).

Salmonella infection can be more serious in certain groups of people. Children younger than five, older adults, and those with weaker immune systems from medical conditions, such as diabetes, liver or kidney disease, and cancer or their treatment, may need medical attention.

How do you prevent Salmonella?

Salmonella can be found in a variety of foods including beef, chicken, eggs, fruits, pork, sprouts, vegetables, and even processed foods, such as nut butters and chicken nuggets. All that's to say, it's difficult to completely avoid all sources of possible Salmonella infections—especially when consuming food or drinks that you don't personally make.

There are, however, certain steps you can take to help decrease your chances of becoming infected by your own food preparation and storage techniques. "Salmonella thrives in warm weather, so it is key to practice safe food handling techniques such as refrigerating foods within two hours of purchasing or preparation," Sims says. "If it is hotter than 90 degrees Fahrenheit, chill the food within one hour."

The CDC also advises washing your hands and surfaces often, and washing fruits and vegetables before eating, cutting, or peeling. It's important to store food that won't be cooked before it is eaten, such as fresh fruit, salads, and deli meats, away from raw meat, poultry, and seafood. And when you cook your food, make sure it's at a temperature high enough to kill germs.