The U.S. is experiencing the first listeriosis outbreak in 2015, with case counts growing and three people dead.
The following are five things to know about the disease, this outbreak and outbreaks in the past.
1. Listeriosis is a sometimes fatal infection caused when people eat food contaminated with Listeria monocytogenes, according to the Centers for Disease Control and Prevention. It affects 1,600 people each year in the U.S., and pregnant women, older people, newborns and people with weakened immune systems are most susceptible to developing the infection.
Listeria monocytogenes is commonly found in soil and water, and animals can carry it and contaminate animal-based foods like meats and dairy. Once a food processing factory is contaminated, the bacteria can live there for years, according to the CDC. The bacteria can be killed by cooking and pasteurization.
2. There are two listeria-related events happening in the U.S. currently. The current outbreak of listeriosis in the U.S. is linked to Blue Bell Creameries ice cream. News of the contaminated ice cream broke in Kansas in March, when five patients at Via Christi St. Francis Hospital in Wichita developed listeriosis after eating Blue Bell ice cream while at the hospital. Three of the five patients have since died. After the problem was discovered and linked to the ice cream, Blue Bell Creameries removed 10 products from the market.
3. Since the initial ice cream-related infections in Kansas, three more Americans have developed listeriosis after eating Blue Bell ice cream, this time in Texas, according to the CDC. The three new cases were all patients who were hospitalized for unrelated problems and then developed listeriosis from 2011 through 2014. According to the USA Today, the patients all ate 3-ounce cups of Blue Bell product that was part of the original recall.
Blue Bell Creameries suspended operations at an Oklahoma factory that is linked to the contaminated product, and the company also issued two more recalls.
4. While the country is dealing with this deadly ice cream-related outbreak, another listeria-related recall was recently announced: Sabra Dipping Co. issued a nationwide voluntary recall of some of its classic hummus, since it may be contaminated with Listeria monocytogenes. According to the U.S. Food and Drug Administration, just five of the classic hummus items have been recalled, and the possible contamination has not been linked to any illnesses.
5. This is not the first time the U.S. has dealt with a listeria outbreak. The largest such outbreak in the U.S. happened in 2011, when 147 people fell ill, 33 people died and one miscarriage occurred throughout 28 states. All of these cases were associated with eating cantaloupe grown at a single farm. More recently, in 2014, the country experienced four listeriosis outbreaks, linked to things like cheese, sprouts and prepackaged caramel apples.