Though many may not realize it, foodborne outbreaks cause millions of Americans to get sick each year. In fact, according to estimates from the Centers for Disease Control and Prevention (CDC), 48 million illnesses, 128,000 hospitalizations, and 3,000 deaths occur each year as the result of foodborne germs.

From salmonella to E. coli to campylobacter, there are many causes of food poisoning that can make you sick.

Symptoms of food poisoning can range from mild diarrhea to vomiting and can quickly escalate to the point of being life-threatening.

Though you can't see where the germs that cause food poisoning might be lurking, you can take steps to prevent being exposed to them. It often comes down to food safety: By storing, cleaning, preparing, and cooking foods properly, you can help yourself avoid some of the common "bugs," such as E. coli and salmonella, that typically cause food poisoning.

7 Types of Germs That Cause Food Poisoning

1. Salmonella

Most people are familiar with the term salmonella, but they may not know that there are more than 2,000 different types of the bug. It's usually associated with animal products like chicken, eggs, and milk, but raw vegetables and even water can carry salmonella, too.

Salmonella is usually introduced to foods at a processing plant or when the foods are handled.

"Symptoms of salmonellosis vary from a mild gastroenteritis [stomach and intestinal inflammation] to more severe and prolonged diarrhea," says Kristina D. Mena, PhD, regional dean of the UTHealth School of Public Health in El Paso. It is a common diagnosis of infectious diarrhea in the United States.

2. E. coli

In the past, E. coli was commonly associated with undercooked ground beef, but recently the germ has shown up in other places, as well. "Outbreaks of E. coli have involved a wide variety of food, including fresh produce, beef, nuts, water, and cookie dough, to name a few," Dr. Mena says. Symptoms can include nausea and vomiting, watery diarrhea, or sometimes bloody diarrhea, depending on the E. coli type.

3. Campylobacter

It's not as well-known as salmonella and E. coli, but campylobacter can be pretty nasty in its own right. "Campylobacter is identified more often than any other causative agent of gastroenteritis in the United States and Europe," Mena says. "This bacterium may also cause high fever, arthritis, and Guillain-Barré syndrome [severe, progressive muscle weakness]. Most often, infections and subsequent illnesses result from the consumption of contaminated poultry or poultry products."

4. Shigella

Though meats are commonly thought of as the transmitters of food poisoning germs, shigella is typically passed along via vegetables, often related to breakdowns in food safety. "Transmission is most often associated with infected food handlers who pass the bacteria from person to person due to poor hygiene practices," Mena says. "It has also been suggested that flies may have a role in its transmission." Symptoms typically include abdominal cramps and bloody stools.

5. Listeria

Outbreaks of listeria in the United States have been linked to produce; raw, unpasteurized milks and cheese; ice cream; and raw or undercooked poultry and seafood. Similar to other foodborne illnesses, a listeria infection can cause diarrhea and fever. These infections can be especially dangerous for pregnant women and can lead to stillbirth, miscarriage, premature birth, or life-threatening infection to the newborn.

6. Botulism

One of the most serious causes of food poisoning is botulism, which is most commonly associated with improperly canned vegetables or cured pork and ham. "This bacterium produces a neurotoxin that results in paralysis," Mena says. "Besides paralysis, symptoms may include body aches, nausea, vomiting, weakness, and an inability to swallow. People who are not treated immediately have a much higher chance of dying."

7. Enteric Viruses

Enteric, or intestinal, viruses like norovirus and hepatitis A are tied to an increasing number of food poisoning outbreaks in recent years, Mena says. "Noroviruses are the viruses that have been implicated in the string of cruise ship outbreaks," she says. "Besides diarrhea, people also typically experience vomiting. Norovirus outbreaks have been associated with a variety of food, including shellfish."

Hepatitis A outbreaks can typically be traced back to poor food safety during food handling. "Hepatitis A infections may result in nausea, malaise, and jaundice, with the more severe illnesses occurring in older individuals," Mena says.

Top Foods Likely to Cause Food Poisoning

Raw or undercooked meat and poultry
Raw or lightly cooked eggs
Unpasteurized milk, cheese, or other dairy products
Seafood and raw shellfish
Fruits and vegetables
Raw flour
Sprouts, such as alfalfa and mung bean

Preventing Food Poisoning

The foods that cause food poisoning may vary, but many of the food safety tips for preventing them are the same. Here is what Mena recommends:

Wash your hands thoroughly with soap and hot water before and after preparing food, as well as after handling each different kind of food.
Keep raw and cooked food separate at all times.
Use separate cutting boards for raw meats and vegetables.
Hot foods should be maintained above 140 degrees F, and cold foods should be stored below 40 degrees F.
Use a food thermometer and be sure to cook meat thoroughly and at adequately high temperatures (165 degrees F for chicken and turkey, for example).
Refrigerate leftovers promptly.
Avoid foods that have been kept at room temperature for more than two hours.
Be wary of potlucks, especially involving perishable foods and in instances when you are uncertain when the food was prepared and for how long it has been stored at potentially improper temperatures.

Handling food correctly may take a few extra steps, but it's important to safeguard your health.

Additional reporting by Ashley Welch.

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