Listeriosis, 2013

Twelve cases of listeriosis were reported during 2013. Eleven cases were hospitalized, and 2 (17%) died. The median age of cases was 63 years (range, 0 days to 87 years). Six (50%) cases had Listeria monocytogenes isolated from blood, 5 (42%) from cerebrospinal fluid (CSF), and 1 (8%) from a boil. Two of the cases were pregnancy-associated: 1 neonate had L. monocytogenes cultured from blood at birth, and 1 neonate developed fever and diarrhea 8 days after birth and had L. monocytogenes isolated from CSF; both cases survived.

Two cases were part of a multi-state outbreak of 6 cases from five states due soft ripened cheese made from pasteurized milk at a Wisconsin plant. The 12 cases reported in 2013 represent an increase from the median number of cases reported from 1996 through 2012 (median, 7 cases; range, 3 to 19), and the highest number of cases reported since 2005.

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. Persons at highest risk should: 1) avoid soft cheeses (e.g., feta, Brie, Camembert, blue-veined, and Mexican-style cheeses) and unpasteurized milk; 2) thoroughly heat/reheat deli meats, hot dogs, other meats, and leftovers; and 3) wash raw fruits and vegetables.

• For up to date information see>> Listeriosis (Listeria)
  
• Full issue>> Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health, 2013