ATLANTA — A rare U.S. outbreak of typhoid fever has been linked to a frozen tropical fruit product used to make smoothies, health officials reported Thursday.

Seven cases have been confirmed — three in California and four in Nevada. Two more California cases are being investigated. Five people were hospitalized, according to the Centers for Disease Control and Prevention said.

The CDC said five of the victims drank milkshakes or smoothies made with frozen mamey (ma-MAY') fruit pulp. Four of them used pulp sold by Goya Foods Inc. of Secaucus, N.J.

Mamey is a sweet, reddish tropical fruit grown mainly in Central and South America. It is also known as zapote or sapote. It is peeled and mashed to make pulp, the CDC said.

The company has recalled packages of the pulp, sold in mostly western states. A sample from one package found in Las Vegas tested positive for the bacteria that causes typhoid, the Food and Drug Administration reported Wednesday.

A phone call to Goya seeking comment was not immediately returned Thursday.

No other food was linked to the illnesses, which occurred between April and July. The victims range in age from 4 to 31, said CDC spokeswoman Arleen Porcell-Pharr.

Typhoid fever is a life-threatening illness caused by a type of bacteria called Salmonella typhi. It's become rare in the United States. There are only about 400 cases annually, and most people caught it while traveling abroad.

Three food-related outbreaks have been reported in the last 12 years. One, also linked to frozen mamey pulp, caused three illnesses in Florida in 1999. One, linked to Gulf Coast oysters, sickened six in Texas in 2006. The third, linked to a Maryland restaurant, caused four illnesses.

Symptoms include a sustained fever as high as 103 to 104 degrees, along with headache. weakness, stomach pains or loss of appetite. Some patients have a rash of flat, rose-colored spots. It can be treated with antibiotics.

It's not clear if there will be additional cases, said Dr. Ezra Barzilay, the CDC epidemiologist supervising the investigation. It can take between three days to eight weeks for an infected person to develop symptoms, he noted.

The disease is still common in the developing world. The bacteria passes through the intestinal tract and often spreads to others through feces-tainted food or water. Freezing does not kill it.

The recalled mamey pulp was sold in 14-ounce plastic packages in Alaska, Arizona, California, Colorado, Hawaii, New Mexico, Nevada, Oregon, Texas, Utah and Washington.