E. coli outbreak linked to raw cheese. See affected products, states.

The Centers for Disease Control and Prevention and the Food and Drug Administration are investigating an outbreak of E. coli linked to cheddar cheese made with raw milk.

In notices shared on March 15, both agencies advised consumers to avoid eating Raw Farm-branded cheddar cheese. An outbreak of E. coli poisoning, a foodborne disease, has been traced back to the cheese products, which have sickened at least seven people across three states, they said.

The cheese has yet to be removed from the market, as Raw Farm, which has been attached to multiple high-profile outbreaks, has declined the FDA's request to recall its products, said the agency. The FDA is awaiting further sample testing to confirm the source of the outbreak.

Here's what to know about the outbreak.

What cheese is affected?

The outbreak has been traced back to cheddar cheese products sold by the brand Raw Farm. This includes:

• Original flavor Raw Farm cheddar cheese.
• All sizes of Raw Farm block and shredded cheese packages.

Which states have E. coli cases?

As of March 14, seven people were sick, including two who were hospitalized, across three states. Four of the cases were in children 3 years old or younger.

• California (five cases)
• Florida (one case)
• Texas (one case)

What to do with impacted cheddar cheese

Raw Farm declined the FDA'S request to voluntarily recall its cheese products.

While the investigation is ongoing, the FDA and CDC advise against eating any affected cheeses and throwing them away. Surfaces that may have touched the cheese should be washed and sanitized with hot, soapy water.

What is Shiga toxin-producing E. coli or STEC? Is it more dangerous?

The outbreak strain of E. coli linked to the cheese has been identified as Shiga toxin-producing E. coli, also known as STEC. This type of E. coli is known to cause a serious kidney condition called hemolytic uremic syndrome, or HUS, according to the FDA.

Children are more likely to suffer from HUS, which damages blood vessels, according to the Mayo Clinic. This causes red blood cells to break down, causing anemia and clots in the blood vessels. These clots may damage the kidneys and other organs and cause kidney failure and death.

No deaths or cases of HUS have been reported as of March 14, said the FDA.

Symptoms of E. coli poisoning

According to the CDC, symptoms of E. Coli poisoning appear two to eight days after exposure and usually last about a week. These can include:

• Diarrhea and a fever higher than 102°F
• Diarrhea for more than three days
• Bloody diarrhea
• So much vomiting that you cannot keep liquids down
• Signs of dehydration, such as dry mouth, reduced urination and dizziness.
• Abdominal cramping, pain or bloating.

HUS has some additional symptoms, according to the Mayo Clinic, including:

• Pallor or loss of color in the skin.
• Extreme tiredness.
• Easy bruising.
• Unusual bleeding, such as bleeding from the nose and mouth.
• Decreased urination or blood in the urine.
• Swelling, called edema, of the legs, feet or ankles.
• Confusion, seizures or stroke.
• High blood pressure.

What to know about raw/unpasteurized dairy

Raw Farm is a seller of raw or unpasteurized dairy products, or dairy that has not been heated to kill harmful germs.

The process of pasteurization became routine in the commercial milk supply in the United States in the 1920s and was widespread by the 1950s. As a result, illnesses commonly spread via milk became less prevalent.

While misinformation about the process has led some to believe that pasteurized milk is less nutritious or better for people with lactose intolerance, pasteurization does not significantly compromise the nutritional value or content of milk. In some states, selling raw milk directly to a consumer is illegal.

Raw milk can carry a host of harmful bacteria such as salmonella, E. coli, listeria and Staphylococcus aureus, among many others. These bacteria are known to cause a host of ailments, including listeriosis, typhoid fever, tuberculosis, diphtheria, Guillain-Barré syndrome, miscarriage, brucellosis, chronic inflammatory conditions, reactive arthritis and death.