Listeria illnesses, deaths, and outbreaks — US, 2009–2011

Whenever I get the chance to talk – a food safety lecture, a journalism discussion, coaching girls’ hockey – I always work in a reference to Listeria and the risk for moms-to-be.

I have five daughters; one of my daughters has a son; and yet the knowledge of Listeria risk is fleeting.

Doctors and medical types usually don’t help.

The U.S. Centers for Disease Control reports today that older adults, pregnant women, and persons with immunocompromising conditions are at higher risk amy.pregnant.listeriathan others for invasive Listeria monocytogenes infection (listeriosis), a rare and preventable foodborne illness that can cause bacteremia, meningitis, fetal loss, and death.

Nationwide, 1,651 cases of listeriosis occurring during 2009–2011 were reported. The case-fatality rate was 21%. Most cases occurred among adults aged ≥65 years (950 [58%]), and 14% (227) were pregnancy-associated. At least 74% of nonpregnant patients aged <65 years had an immunocompromising condition, most commonly immunosuppressive therapy or malignancy. The average annual incidence was 0.29 cases per 100,000 population. Compared with the overall population, incidence was markedly higher among adults aged ≥65 years (1.3; relative rate [RR]: 4.4) and pregnant women (3.0; RR: 10.1). Twelve reported outbreaks affected 224 patients in 38 states. Five outbreak investigations implicated soft cheeses made from pasteurized milk that were likely
contaminated during cheese-making (four implicated Mexican-style cheese, and one implicated two other types of cheese). Two outbreaks were linked to raw produce.

Almost all listeriosis occurs in persons in higher-risk groups. Soft cheeses were prominent vehicles, but other foods also caused recent outbreaks. Prevention targeting higher-risk groups and control of Listeria monocytogenes contamination in foods implicated by outbreak investigations will have the greatest impact on reducing the burden of listeriosis.

Refrigerated, ready-to-eat foods are out for moms-to-be; we heated soft cheeses, even the ones made from pasteurized milk. Pregnant women with listeria infections often have only mild symptoms or a fever, but their infections can result in miscarriage, premature labor and serious illness or death in their newborns, the report noted.