Listeria monocytogenes
Tom Duszynski, MPH, REHS Director of Surveillance and
Inves>ga>on
References
• Scallan, E., Hoekstra R.M., Angulo F.J., Tauxe R.V., Widdowson M.A., Roy S.L., et al. Foodborne illness acquired in the United States-‐-‐-‐major pathogens. Emerg Infect Dis 2011; 17(1): 7-‐15.
• Retrieved from hYp://www.cdc.gov/listeria/defini>on.html on December 27, 2011
• Retrieved from hYp://www.cdc.gov/listeria/outbreaks/cantaloupes-‐jensen-‐farms/index.html on December 27, 2011
Listeria monocytogenes
• Bacterium Listeria monocytogenes, is an important public health problem in the United States.
• The disease primarily affects older adults, pregnant women, newborns, and adults with weakened immune systems.
• Rarely, persons without these risk factors can also be affected.
Listeria monocytogenes • Listeria monocytogenes, a gram-‐posi>ve rod-‐shaped bacterium, commonly found in soil and water.
• Animals can carry the bacterium without appearing ill and can contaminate foods of animal origin, such as meats and dairy products.
• Most human infec>ons follow consump>on of contaminated food. Rare cases of nosocomial transmission have been reported.
Where it can be found • The bacterium has been found in a variety of raw foods, such as uncooked meats and vegetables
• Foods that become contaminated a^er cooking or processing, such as so^ cheeses, processed meats such as hot dogs and deli meat (both products in factory-‐sealed packages and products sold at deli counters), and smoked seafood.
Where it can be found • Unpasteurized (raw) milk and cheeses and other foods made from unpasteurized milk are par>cularly likely to contain the bacterium.
• Listeria is killed by pasteuriza>on and cooking; however, in some ready-‐to-‐eat foods, such as hot dogs and deli meats, contamina>on may occur a^er factory cooking but before packaging.
• Unlike most bacteria, Listeria can grow and mul>ply in some foods in the refrigerator.
Who Gets Listeriosis? • Pregnant women are about 20 >mes more likely than other healthy adults to get listeriosis. About one in six (17%) cases of listeriosis occurs during pregnancy.
• Newborn babies suffer the most serious effects of infec>on in pregnancy.
• Persons with weakened immune systems from transplants or certain diseases, therapies, or medica>ons.
Who Gets Listeriosis? • Persons with cancer, diabetes, alcoholism, liver or kidney disease.
• Persons with AIDS are almost 300 >mes more likely to get listeriosis than people with normal immune systems.
• Older adults • Healthy children and adults occasionally get infected with Listeria, but they rarely become seriously ill.
Patients with non-pregnancy-associated listeriosis, by age group and sex, Listeria Initiative, 2009 (n=421).
Challenges of recogni>on
• Incuba>on Period for Listerosis is 3-‐70 days with a median incuba>on of 3 weeks
• Signs and Symptoms mimic many other infec>ons
• The bacteria can stay in the body a long >me before making a person sick, allowing more people to be infected
Signs and Symptoms
• A person with listeriosis usually has fever and muscle aches, some>mes preceded by diarrhea or other gastrointes>nal symptoms.
• Almost everyone who is diagnosed with listeriosis has "invasive" infec>on, in which the bacteria spread beyond the gastrointes>nal tract. The symptoms vary with the infected person
Signs and Symptoms
• Symptoms, in addi>on to fever and muscle aches, can include headache, s>ff neck, confusion, loss of balance, and convulsions.
• Pregnant women typically experience only a mild, flu-‐like illness. Infec>ons can lead to miscarriage, s>llbirth, premature delivery, or life-‐threatening infec>on of the newborn.
Surveillance • Listeriosis (infec>on with Listeria monocytogenes) was added to the list of na>onally no>fiable diseases in 2001.
• To improve surveillance, the Council of State and Territorial Epidemiologists has recommended that all L. monocytogenes isolates be forwarded to state public health laboratories for subtyping
Sta>s>cs • Listeria monocytogenes is es>mated to cause nearly 1,600 illnesses (Listeriosis) each year in the United States, with more than 1,400 hospitaliza>ons and 250 deaths
• Compared to 1996-‐1998, the incidence of listeriosis had declined by about 38% by 2003.
Sta>s>cs
• On average from 1998-‐2008, 2.4 outbreaks per year were reported to CDC.
• Before 2011, the largest outbreak occurred in 2002, when 54 illnesses, 8 deaths, and 3 fetal deaths in 9 states were found to be associated with consump>on of contaminated turkey deli meat.
How do I know if I have Listeriosis? • If you develop fever and chills while pregnant or if you are very sick with fever and muscle aches or s>ff neck, consult your doctor immediately.
• A blood or spinal fluid test (to look for the bacteria) will show if you have listeriosis.
Diagnosis & Tes>ng
• Diagnosis is confirmed only a^er isola>on of Listeria monocytogenes from a normally sterile site, such as blood, or from amnio>c fluid or the placenta in the semng of pregnancy.
Treatment & Outcomes
• Listeriosis is treated with an>bio>cs. A person in a high-‐risk category who experiences flu-‐like symptoms within 2 months of ea>ng contaminated food should seek medical care
• Even with prompt treatment, some listeriosis cases result in death. This is par>cularly likely in older adults and in persons with other serious medical problems.
The 2011 Outbreak
Listerosis and Cantaloupes • In 2011, cantaloupes contaminated with the bacteria Listeria monocytogenes caused the deadliest foodborne disease outbreak in the United States in nearly 90 years.
Outbreak Inves>ga>on
• September 2 – Listeria 'spike' reported in Colorado
• Local doctors report seven cases of listeria infec>on far more than usual
• Outbreak defini>on: More cases of disease than expected in a given popula>on at a given >me
Outbreak Inves>ga>on
• September 2: The Colorado Department of Public Health and Environment (CDPHE) no>fies the Centers for Disease Control and Preven>on (CDC) of seven ill persons with listeriosis (Listeria infec>on) reported since 8/29/11.
• September 5: Cantaloupes are collected by CDPHE for Listeria tes>ng from the home of an ill person.
Outbreak Inves>ga>on • September 6th PulseNet defines the Outbreak strain Cases seen in the NE and Texas with the strain
Outbreak Inves>ga>on
• September 7th-‐-‐ CDC begins coordina>on of a mul>-‐state inves>ga>on
• September 8th—States with cases are asked to use supplemental ques>onnaire to learn more about possible exposure
• September 9th– Cantaloupes are iden>fied as a likely suspect in the outbreak.
Outbreak Inves>ga>on
• September 10: FDA and CDPHE visit Jensen Farms for an inspec>on and to collect environmental and product samples. The broker for Jensen Farms stops distribu>on of cantaloupes and tells grocery stores to remove Jensen Farms cantaloupes from shelves.
• September 11th – Preliminary Traceback suggests cantaloupes were produced at Jensen Farms
Outbreak Inves>ga>on
• September 12th– CDC post mul>state outbreak informa>on of Listeriosis linked to cantaloupes and issues na>onal listeria warning, saving many lives
• September 13th – FDA issues a statement that most ill people consumed cantaloupes
• September 14th – CDC posts a web update linking the listerosis cases to cantaloupes produced at Jensen Farms.
Outbreak Inves>ga>on
• September 22: FDA, along with CO state and local officials, begins an environmental assessment at Jensen Farms.
• September 23: Carol’s Cuts of Kansas City, Kansas ini>ates a recall of cantaloupe
• October 6: Fruit Fresh Up of Buffalo, New York ini>ates a recall of individual packages of fresh cut cantaloupe
Outbreak Inves>ga>on
• October 18: FDA issues a warning leYer to Jensen Farms based on the presence of the outbreak strains of Listeria in environmental and cantaloupe samples taken on 9/10.
• October 19: FDA announces findings of its environmental assessment at Jensen Farms
Outbreak Inves>ga>on • 146 cases, 30 deaths, and 1 miscarriage in 28 states.
• Onset ranged from July 31, 2011 through October 27, 2011.
• Ages ranged from <1 to 96 years, median age of 77 years.
• Most ill persons were over 60 years old. 58% of ill persons were female.
• Among the 144 ill persons 142 (99%) were hospitalized.
Outbreak Inves>ga>on
• Collabora>ve inves>ga>ons by local, state, and federal public health and regulatory agencies indicated that the source of the outbreak was whole cantaloupe grown at Jensen Farms’
• Among the 140 ill persons with available informa>on on what they ate, 131 (94%) reported consuming cantaloupe in the month before illness onset.
Outbreak and Lab Tes>ng
• Laboratory tes>ng by the Colorado Department of Public Health and Environment iden>fied Listeria monocytogenes outbreak strains on cantaloupes collected from grocery stores and from ill persons' homes.
• Product traceback informa>on from Colorado state officials indicated that these cantaloupes also came from Jensen Farms.
Ques>ons • Wash your hands • Stay home if you’re sick • Get your vaccines
• Tom Duszynski, [email protected] 317-‐233-‐7009