MMWR Morb Mortal Wkly Rep. 2013 Jun 7;62(22):448-52.
Older adults, pregnant women, and persons with immunocompromising conditions are at higher risk than others for invasive Listeria monocytogenes infection (listeriosis), a rare and preventable foodborne illness that can cause bacteremia, meningitis, fetal loss, and death.
This report summarizes data on 2009-2011 listeriosis cases and outbreaks reported to U.S. surveillance systems. The Listeria Initiative and PulseNet conduct nationwide surveillance to rapidly detect and respond to outbreaks, the Foodborne Diseases Active Surveillance Network (FoodNet) conducts active, sentinel population-based surveillance to track incidence trends, and the Foodborne Disease Outbreak Surveillance System (FDOSS) receives reports of investigated outbreaks to track foods and settings associated with outbreaks.
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.
Careful attention to food safety is especially important to protect vulnerable populations. Surveillance for foodborne infections like listeriosis identifies food safety gaps that can be addressed by industry, regulatory authorities, food preparers, and consumers.
老年人、孕妇和免疫功能低下者比其他人更容易感染李斯特菌属（李斯特菌病），这是一种罕见且可预防的食源性疾病，可引起菌血症、脑膜炎、胎儿流产和死亡。
本报告总结了美国监测系统报告的 2009-2011 年李斯特菌病病例和暴发的数据。李斯特菌病倡议和脉冲网进行全国范围的监测，以快速发现和应对暴发；食源性疾病主动监测网络（FoodNet）进行主动、哨点人群为基础的监测，以跟踪发病率趋势；食源性疾病暴发监测系统（FDOSS）接收调查暴发的报告，以跟踪与暴发相关的食物和场所。
全国范围内，2009-2011 年报告了 1651 例李斯特菌病病例。病死率为 21%。大多数病例发生在年龄≥65 岁的成年人中（950[58%]），14%（227）与妊娠有关。年龄<65 岁的非孕妇中，至少有 74%患有免疫功能低下的疾病，最常见的是免疫抑制治疗或恶性肿瘤。年平均发病率为每 10 万人 0.29 例。与总体人群相比，年龄≥65 岁的成年人（1.3；相对危险率[RR]：4.4）和孕妇（3.0；RR：10.1）的发病率明显更高。报告了 12 起暴发，涉及 38 个州的 224 名患者。五项暴发调查涉及用巴氏杀菌奶制成的软奶酪，这些奶酪在奶酪制作过程中可能受到污染（四项涉及墨西哥风格的奶酪，一项涉及另外两种奶酪）。两起暴发与生农产品有关。
几乎所有李斯特菌病都发生在高危人群中。软奶酪是主要的传播媒介，但其他食物也导致了最近的暴发。针对高危人群的预防和控制暴发调查中涉及的食品中李斯特菌属的污染，将对减少李斯特菌病的负担产生最大影响。
对食品安全的谨慎关注对于保护弱势群体尤为重要。对食源性感染（如李斯特菌病）的监测可发现食品安全漏洞，可由行业、监管机构、食品准备者和消费者解决。
