SOURCES: U.S. Centers for Disease Control and Prevention, news release, Dec. 19, 2014; Ambreen Khalil, M.D., infectious disease specialist, Staten Island University Hospital, New York City; Leonard Krilov, M.D., chief of pediatric infectious diseases, Winthrop-University Hospital, Mineola, N.Y.
FRIDAY, Dec. 19, 2014 (HealthDay News) -- U.S. and state health officials are investigating a listeria outbreak linked to caramel apples that has killed at least four people and sickened 28 others in 10 states.
Consumers should not eat any commercially produced, prepackaged caramel apples until more information becomes available, the U.S. Centers for Disease Control and Prevention said in a news release.
As of Dec. 18, a total of 28 people had been infected with the outbreak strains of the bacteria Listeria monocytogenes. Of the 26 people who have been hospitalized, five have died. Listeria infections contributed to at least four of those deaths, the agency said.
Nine illnesses occurred in pregnant women or newborn infants, and there have been three cases of invasive illness (meningitis) among otherwise healthy children aged 5 to 15, the CDC said.
Symptoms of listeria infection include fever, chills, headache, upset stomach and vomiting. Antibiotics are typically used to treat the infection.
Of the 18 ill people interviewed so far, 15 said they ate commercially produced, prepackaged caramel apples before becoming sick. To date, no illnesses have been linked to apples that are not caramel-coated and prepackaged, or to caramel candy.
Although caramel apples are usually sold in the fall, the CDC said they may still be for sale in stores or may be in consumers' homes.
Investigators are trying to identify specific brands of caramel apples that may be linked to the outbreak, and to pinpoint the source of contamination, the CDC said.
Dr. Ambreen Khalil is an infectious disease specialist at Staten Island University Hospital in New York City. She explained that listeria is a "food-borne illness that can [show up] in different forms, including bloodstream infections, infections of the central nervous system such as meningitis, or brain abscesses, gastroenteritis or endocarditis," which can affect the heart.
Listeria poses particular problems for people with weakened immune systems as well as pregnant women and the elderly, Khalil said.
Dr. Leonard Krilov, chief of pediatric infectious diseases at Winthrop-University Hospital in Mineola, N.Y., said recommended guidelines to prevent listeria infection include rinsing raw produce or scrubbing firm-skinned produce -- such as melons and cucumbers -- and then drying them well.
The U.S. National Library of Medicine has more about listeria infections.