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Listeria monocytogenes and listeriosis

Listeria monocytogenes and listeriosis. Megan Antosik, RD . Agenda. History Microbiology Related foods Infection Pathogenesis At-Risk Populations. Diagnosis & Treatment Outbreak History Current Outbreaks Prevention. Objectives.

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Listeria monocytogenes and listeriosis

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  1. Listeriamonocytogenes and listeriosis Megan Antosik, RD

  2. Agenda • History • Microbiology • Related foods • Infection • Pathogenesis • At-Risk Populations • Diagnosis & Treatment • Outbreak History • Current Outbreaks • Prevention

  3. Objectives • After this presentation, audience members will be able to: • Identify at-risk populations for contracting Listeria monocytogenes. • List 3 foods highly susceptible to contamination of Listeriamonocytogenes • Describe the clinical characteristics used to diagnose and identify listeriosis.

  4. History • Hayem (France, 1891) & Henle (Germany, 1893) • Hulphers (Sweden, 1911) assigned the name Bacillus hepatitis • 1919 - French clinicians preserved a diphtheroid isolated form of spinal fluid cultures of a patient with meningitis • 1924- Bacterium monocytogenes, named for the monocytosis it produced in rabbits Gellin et al 1989

  5. History • Lord Joseph Lister (1925) – Listerellahepatolytica • Nyfeldt (1929) • Listeria monocytogenes (1940) Gellin et al 1989

  6. Listeria • Seven species of Listeria • Listeria monocytogenes • Listeria ivanovii • Listeria seeligeria • Listeria welshimeri Gellin et al 1989

  7. Listeria monocytogenes • Facultative anaerobe • ß-hemolytic • Gram-positive • Non-acid fast • Non-sporulating linear rod • Can grow at temperatures as low as 4°C • Incubation period of 5-70 days www.bellenews.com Gellin et al 1989

  8. L. monocytogenes • Sixteen serotypes • Only 3 responsible for more than 90% of human disease • Serotype 4b • Serotype 1/2b • Serotype 1/2a http://en.wikipedia.org/wiki/File:Serotypes_%E2%80%93_Antibody_versus_antigen.svg Gellin et al 1989

  9. L. monocytogenes • Ubiquitous in nature: • Dust • Soil • Water • Sewage • Decaying vegetation Animals can carry bacterium and transmit to food www.zoenature.org Gellin et al 1989

  10. As a dietitian, what can we do? • How would you protect against an invader of this magnitude??

  11. Susceptible Foods • Ready-to-Eat (RTE) foods • Hot dogs • Delicatessen meats • Soft cheeses • Raw foods • Meat • Fruits • Vegetables • Unpasteurized foods • Milk and milk products static.howstuffworks.com/gif/hot-dog-km.

  12. +  Transmission Etiologic agent Reservoir  Leads to… Susceptible food Consumption of contaminated food

  13. Listeriosis • Severe infection • Consumption of foods contaminated by L. monocytogenes • Symptoms • Chills • Fever • Muscle aches • Diarrhea • Other GI symptoms

  14. Pathogenesis • http://www.youtube.com/watch?v=mWjS3qDj6uw&feature=related • Intracellular pathogen • Entry, growth, movement and spread in a macrophage • Phagocytosis • Actin filaments “comet tail” • Bypasses humoral immune system Tilney et al 1989

  15. Pathogenesis

  16. At Risk? • In the United States, an estimated 1,600 persons become seriously ill with listeriosis each year. Of these, 260 die. • Older adults • Pregnant women • Newborns • Immunocompromised • General public www.cdc.gov

  17. Manifestations • Diagnosis of “invasive” listeriosis • Symptoms include: • Headache • Stiff neck • Confusion • Loss of balance • Convulsions www.cdc.gov

  18. Listeriosis in Older Adults and the Immunocompromised • Host-dependent • Septicemia • Meningitis • Death • Persons with AIDS: They are almost 300 times more likely to get listeriosis than people with normal immune systems. www.cdc.gov

  19. Listeriosis in Pregnant Women • Twenty times more likely to get listeriosis. About one in six (17%) cases occurs during pregnancy • Commonly experience mild “flu-like” symptoms • Infections: • Still birth • Miscarriage • Premature delivery • Life-threatening Infection of the newborn www.cdc.gov

  20. Diagnosis • Blood • Cerebrospinal fluid (CSF) • Amniotic fluid • No stool or serological tests available www.cdc.gov

  21. Treatment • Most cases can spontaneously be cleared within 7 days • Otherwise - treated with IV antibiotics • Ampicillin • Bactrim www.cdc.gov

  22. Outbreak History

  23. Outbreak History

  24. What can we do? • Activate Listeria Initiative • USDA FSIS & FDA • “Zero Tolerance” policy • Initiate the Healthy People objective • Achieve a 50% reduction in listeriosis incidence by 2010 • 2.5 cases per 1 million people Voetsch et al 2007

  25. How do we evaluate efficacy? • Active surveillance studies • 1996-2003 • Foodborne Disease Active Surveillance Network (FoodNet) • Assess consumer practices Voetsch et al 2007

  26. http://www.cdc.gov/nationalsurveillance/PDFs/ListeriaCaseReportFormOMB0920-0004_alfalfa.pdfhttp://www.cdc.gov/nationalsurveillance/PDFs/ListeriaCaseReportFormOMB0920-0004_alfalfa.pdf

  27. http://www.cdc.gov/nationalsurveillance/PDFs/ListeriaCaseReportFormOMB0920-0004_alfalfa.pdfhttp://www.cdc.gov/nationalsurveillance/PDFs/ListeriaCaseReportFormOMB0920-0004_alfalfa.pdf

  28. What did we find? • N=766 isolates from 1996-2003 • 670 hospitalizations • 153 fatalities • 122 pregnant-associated cases Voetsch et al 2007

  29. Demographics

  30. Crude Incidence 1996-2003

  31. Did we achieve our goals? • Incidence of invasive listeriosis decreased by 24% • Pregnancy-associated decreased by 37% • Decrease of 23% in patients > 50 years old • Crude incidence in 2003 was 3.1 cases per 1 million Voetsch et al 2007

  32. Are we in the clear? www.cdc.gov/mmwr

  33. Cantaloupe Outbreak 2011 • Jensen Farms • 146 affected • 28 states • 4 different strains • 30 deaths • 1 miscarriage • Outbreak has officially ended http://www.lamarledger.com/ci_18902388?source=most_viewed http://www.cdc.gov/listeria/outbreaks/cantaloupes-jensen-farms/110211/index.html

  34. http://www.cdc.gov/listeria/outbreaks/cantaloupes-jensen-farms/110211/map.htmlhttp://www.cdc.gov/listeria/outbreaks/cantaloupes-jensen-farms/110211/map.html

  35. http://www.cdc.gov/listeria/outbreaks/cantaloupes-jensen-farms/110211/timeline.htmlhttp://www.cdc.gov/listeria/outbreaks/cantaloupes-jensen-farms/110211/timeline.html

  36. What Went Wrong? • Inspectors ignored federal regulators • FDA cited “serious design flaws” and “lack of awareness” • Bio Food Safety Auditing gave Jensen Farms near perfect marks • Jensen Farms did not have proper chlorine or anti-bacterial wash • Improper equipment

  37. As dietitians, what can we do? • Prevention methods • Food Safety • Cook foods thoroughly • Prevent cross-contamination • Buy pasteurized foods • Proper sanitation • Know where your food comes from • Keep up-to-date on foodborne illness outbreaks • Regulation of food safety policies http://www.foodsafety.gov/keep/index.html

  38. Questions? • Don’t be afraid of food! Just play it safe! www.gettyimages.com

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