Listeriosis, 2014

Seventeen listeriosis cases were reported in 2014. All cases were hospitalized, and 6 (35%) died. The median age of cases was 64 years (range, 0 days to 90 years). Fifteen cases had Listeria monocytogenes isolated from blood, 1 from peritoneal fluid, and 1 from hip fluid. Three of the cases were pregnancy-associated: two neonates had L. monocytogenes cultured from blood at birth, and one pregnant woman developed headache, muscle aches, and sweats at 32 weeks gestation and had L. monocytogenes isolated from blood; all 3 cases and the pregnant case’s infant survived.

The source of infection was identified for 6 cases. Four cases were part of a multi-state outbreak of 35 cases from 12 states due to caramel apples made with contaminated California-packed apples. One case was linked to consumption of recalled stone fruit (peaches, plums, nectarines, pluots) that included 1 other national case. One neonatal case was linked to raw pork purchased from a live animal market.

The 17 cases reported in 2014 represent a 2.5-fold increase from the median number of cases reported from 1996 through 2013 (median, 7 cases; range, 3 to 19), and the highest number of cases reported since 1999.

Elderly persons, immunocompromised individuals, pregnant women, and neonates are at highest risk for acquiring listeriosis. Listeriosis generally manifests as meningoencephalitis and/ or septicemia in neonates and adults. Pregnant women may experience a mild febrile illness, abortion, premature delivery, or stillbirth. In healthy adults and children, symptoms usually are mild or absent. L. monocytogenes can multiply in refrigerated foods.

• For up to date information see>> Listeriosis (Listeria)
  
• Full issue>> Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health, 2014