Four cases of listeriosis were reported during 2001. The first case-patient was a 74-year-old male with a malignant lymphoma; the second was an 82-year-old male; the third was an 85-year-old female with multiple myeloma; and the fourth was an 86-year-old male. All four cases survived their Listeria infections. The mean number of cases reported annually from 1996 to 2000 was 14 (range, seven to 19 cases).
Those at highest risk for acquiring listeriosis are the elderly, pregnant women, neonates, and immunocompromised individuals. Listeriosis generally is manifested as meningoencephalitis and/or septicemia in neonates and adults. Pregnant women may experience a mild febrile illness, spontaneous abortion, premature delivery, or stillbirth. Listeria monocytogenes can multiply in refrigerated foods that are contaminated. Persons at highest risk should avoid soft cheeses (e.g., feta, Brie, Camembert, blue-veined, and Mexican-style cheeses) and unpasteurized milk, should heat/reheat deli meats, hot dogs, other meats, and leftovers thoroughly, and should wash raw vegetables.