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Food Poison Journal

Food Poisoning Outbreaks and Litigation: Surveillance and Analysis

What We All Need To Know About Deadly Listeria During An Outbreak Or Recall

An Introduction to Listeria

Listeria (pronounced liss-STEER-ē-uh) is a gram-positive rod-shaped bacterium that can grow under either anaerobic (without oxygen) or aerobic (with oxygen) conditions. [4, 18] Of the six species of Listeria, only L. monocytogenes (pronounced maw-NO-site-aw-JUH-neez) causes disease in humans. [18] These bacteria multiply best at 86-98.6 degrees F (30-37 degrees C), but also multiply better than all other bacteria at refrigerator temperatures, something that allows temperature to be used as a means of differentiating Listeria from other contaminating bacteria. [18] Called an “opportunistic pathogen,” Listeria is noted to cause an estimated 2,600 cases per year of severe invasive illness. [26] Perhaps not surprisingly then, “foodborne illness caused by Listeria monocytogenes has raised significant public health concern in the United States, Europe, and other areas of the world.” [3] As one noted expert observed, summarizing the history of these bacteria and their significance for public health:

Although L. monocytogenes was recognized as an animal pathogen over 80 years ago, the first outbreak confirming an indirect transmission from animals to humans was reported only in 1983, in Canada’s Maritime provinces. In that outbreak, cabbages, stored in the cold over the winter, were contaminated with Listeria through exposure to infected sheep manure. A subsequent outbreak in California in 1985 confirmed the role of food in disseminating listeriosis.

Since then Listeria has been implicated in many outbreaks of food-borne illness, most commonly from exposure to contaminated dairy products and prepared meat products, including turkey and deli meats, pâté, hot dogs and seafood and fish. [4] Given its widespread presence in the environment and food supply, the ingestion of Listeria has been described as an “exceedingly common occurrence.” [18]

The Incidence of Listeria Infection

Listeria bacteria are found widely in the environment in soil, including in decaying vegetation and water, and may be part of the fecal flora of a large number of mammals, including healthy human adults. [4, 18] According to the FDA, “studies suggest that 1-10% of humans may be intestinal carriers of Listeria.” [14] Another authority notes that the “organism has been isolated from the stool of approximately 5% of healthy adults.” [18] Overall, seasonal trends show a notable peak in total Listeria cases and related-deaths from July through October. [3] Ingested by mouth, Listeria is among the most virulent foodborne pathogens, with up to 20% of clinical infections resulting in death. [3] These bacteria primarily cause severe illness and death in persons with immature or compromised immune systems. [13, 18]

Consequently, most healthy adults can be exposed to Listeria with little to any risk of infection and illness. [4, 11] A study published in 1995 projected Listeria infection-rates to the U.S. population, suggesting that an estimated 1,965 cases and 481 deaths occurred in 1989 compared with an estimated 1,092 cases and 248 deaths in 1993, a 44% and 48% reduction in illness and death, respectively. [25] In comparison, a USDA study published in 1996 estimated that there had been 1,795-1860 Listeria-related cases in 1993, and 445-510 deaths, with 85-95% of these attributable to the consumption of contaminated food. [28] Listeriosis-related mortality rates decreased annually by 10.7% from 1990 through 1996, and by 4.3% from 1996 through 2005. [3]

Among adults 50 years of age and older, infection rates were estimated to have declined from 16.2 per 1 million in 1989 to 10.2 per 1 million in 1993. [25] Perinatal disease decreased from 17.4 cases per 100,000 births in 1989 to 8.6 cases per 100,000 births in 1993. [25] Neonatal infections are often severe, with a mortality rate of 25-50%. [4]

According to the CDC’s National Center for Zoonotic, Vector-Borne, and Enteric Diseases:

Listeriosis was added to the list of nationally notifiable 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 through the National Molecular Subtyping Network for Foodborne Disease Surveillance (PulseNet). All states have regulations requiring health care providers to report cases of listeriosis and public health officials try to interview all persons with listeriosis promptly using a standard questionnaire about high risk foods. In addition, FoodNet conducts active laboratory- and population-based surveillance. [7]

In 2006, public health officials from 48 states reported 1,270 foodborne disease outbreaks, with a confirmed or suspect source in 884 of the outbreaks (70%). [8] Only one of the outbreaks with a confirmed source was attributed to Listeria, with this outbreak involving eleven hospitalizations and one death. [8] The next year, of 17,883 lab-confirmed infections, the CDC attributed 122 to Listeria. [9] In 2009, there were 158 confirmed Listeria infections, representing an incidence-rate of .34 cases for every 100,000 persons in the United States. [10] Such data revealed an incidence-rate of 0.27 cases per 100,000 persons, a decrease of 42% compared with 1996—1998. [10] But, according to CDC’s Technical Information website, it is estimated that there are 1,600 cases of Listeria infection annually in the United States, based on data through 2008. [7]

The 2009 numbers represented a reported 30% decrease in the number of infections compared to the 1996—1998 rates of infection. [10] Although the nature and degree of underreporting is subject to dispute, all agree that the confirmed cases represent just the tip of the iceberg. [6, 13] Indeed, one study estimates the annual incidence rate for Listeria to be around 1,795-1,860 cases per 100,000 persons, with 445-510 of the cases ending in death. [28]

Finally, in a study of FoodNet laboratory-confirmed invasive cases—where infection is detected in blood, cerebrospinal fluid, amniotic fluid, placenta or products of conception—the number of listeriosis cases decreased by 24% from 1996 through 2003. [33] During this same period, pregnancy-associated disease decreased by 37%, while cases among those fifty years old and older decreased by 23%. [33]

The Prevalence of Listeria in Food and the Environment

Listeria is a common presence in nature, found widely in such places as water, soil, infected animals, human and animal feces, raw and treated sewage, leafy vegetables, effluent from poultry and meat processing facilities, decaying corn and soybeans, improperly fermented silage, and raw (unpasteurized) milk. [18, 23, 27] Foods commonly identified as sources of Listeria infection include  improperly pasteurized fluid milk, cheeses (particularly soft-ripened varieties, such as traditional Mexican cheeses, Camembert and ricotta), ice cream, raw vegetables, fermented raw-meat sausages, raw and cooked poultry, and cooked, ready-to-eat (RTE) sliced meats—often referred to as “deli meats”. [18, 21, 23, 28] One study found that, over a five-year period of testing, in multiple processing facilities, Listeria monocytogenes was isolated from 14% of 1,080 samples of smoked finfish and smoked shellfish. [16]

Ready-to-eats foods have been found to be a notable and consistent source of Listeria. [14, 21] For example, a research-study done by the Listeria Study Group found that Listeria monocytogenes grew from at least one food specimen in the refrigerators of 64% of persons with a confirmed Listeria infection (79 of 123 patients), and in 11% of more than 2000 food specimens collected in the study. [21] Moreover, 33% of refrigerators (26 of 79) contained foods that grew the same strain with which the individual had been infected, a frequency much higher than would be expected by chance. [21] A widely cited USDA study that reviewed the available literature also summarized that:

In samples of uncooked meat and poultry from seven countries, up to 70 percent had detectable levels of Listeria [13].  Schuchat [23] found that 32 percent of the 165 culture-confirmed listeriosis cases could be attributed to eating food purchased from store delicatessen counters or soft cheeses.  In Pinner [21] microbiologic survey of refrigerated foods specimens obtained from households with listeriosis patients, 36 percent of the beef samples and 31 percent of the poultry samples were contaminated with Listeria.

The prevalence of Listeria in ready-to-eat meats has not proven difficult to explain. [26, 29] As one expert in another much-cited article has noted:

The centralized production of prepared ready-to-eat food products…increases the risk of higher levels of contamination, since it requires that foods be stored for long periods at refrigerated temperatures that favor the growth of Listeria. During the preparation, transportation and storage of prepared foods, the organism can multiply to reach a threshold needed to cause infection. [4]

The danger posed by the risk of Listeria in ready-to-eat meats has prompted the USDA to declare the bacterium an adulterant in these kinds of meat products and, as a result, to adopt a zero-tolerance policy for the presence of this deadly pathogen. [7, 29]

A USDA Baseline Data Collection Program done in 1994 documented Listeria contamination on 15.0% of broiler-chicken carcasses [30]. Subsequent USDA data-collection did not test for the prevalence of Listeria in chicken or in turkeys. [31, 32]

Transmission and Infection

Except for the transmission of mother to fetus, human-to-human transmission of Listeria is not known to occur. [18] Infection is caused almost exclusively by the ingestion of the bacteria, most often through the consumption of contaminated food. [18, 21, 23] The most widely-accepted estimate of foodborne transmission is 85-95% of all Listeria cases. [23, 28]

The infective dose—that is, the amount of bacteria that must be ingested to cause illness—is not known. [4, 18, 26] In an otherwise healthy person, an extremely large number of Listeria bacteria must be ingested to cause illness—estimated to be somewhere between 10–100 million viable bacteria (or colony forming units “CFU”) in healthy individuals, and only 0.1–10 million CFU in people at high risk of infection. [4, 18, 26] Even with such a dose, a healthy individual will suffer only a fever, diarrhea, and related gastrointestinal symptoms. [4, 18].

The amount of time from infection to the onset of symptoms—typically referred to as the incubation period—can vary to a significant degree.  Symptoms of Listeria infection can develop at any time from 2 to 70 days after eating contaminated food. [4, 5] According to one authoritative text:

The incubation period for invasive illness is not well established, but evidence from a few cases related to specific ingestions points to 11 to 70 days, with a mean of 31 days. In one report, two pregnant women whose only common exposure was attendance at a party developed Listeria bacteremia with the same uncommon enzyme type; incubation periods for illness were 19 and 23 days. [18]

Adults can get listeriosis by eating food contaminated with Listeria, but babies can be born with listeriosis if their mothers eat contaminated food during pregnancy. [4, 24] The mode of transmission of Listeria to the fetus is either transplacental via the maternal blood stream or ascending from a colonized genital tract. [24] Infections during pregnancy can cause premature delivery, miscarriage, stillbirth, or serious health problems for the newborn. [18, 24]

Incidence of Listeria infection in HIV-positive individuals is higher than in the general population. [17, 18] One study found that:

The estimated incidence of listeriosis among HIV-infected patients in metropolitan Atlanta was 52 cases per 100,000 patients per year, and among patients with AIDS it was 115 cases per 100,000 patients per year, rates 65–145 times higher than those among the general population. HIV-associated cases occurred in adults who were 29–62 years of age and in postnatal infants who were 2 and 6 months of age. [17]

Pregnant women make up around 30% of all infection cases, while accounting for 60% of cases involving the 10- to 40-year age group. [18]

Those Most Susceptible to Infection

Several segments of the population are at increased risk and need to be informed so that proper precautions can be taken. [19,20, 27] The body’s defense against Listeria is called “cell-mediated immunity” because the success of defending against infection depends on our cells (as opposed to our antibodies), especially lymphocytes called “T-cells.” [12] Therefore, individuals whose cell-mediated immunity is suppressed are more susceptible to the devastating effects of listeriosis, including especially HIV-infected individuals, who have been found to have a Listeria-related mortality of 29%. [12, 17, 18]

Pregnant women naturally have a depressed cell-mediated immune system. [18, 24] In addition, the immune systems of fetuses and newborns are very immature and are extremely susceptible to these types of infections. [24] Other adults, especially transplant recipients and lymphoma patients, are given necessary therapies with the specific intent of depressing T-cells, and these individuals become especially susceptible to Listeria as well. [7, 18, 27]

According to the CDC and other public health organizations, individuals at increased risk for being infected and becoming seriously ill with Listeria include the following groups:

  • Pregnant women: They are about 20 times more likely than other healthy adults to get listeriosis. About one-third of listeriosis cases happen during pregnancy.
  • Newborns: Newborns rather than the pregnant women themselves suffer the serious effects of infection in pregnancy.
  • Persons with weakened immune systems
  • Persons with cancer, diabetes, or kidney disease
  • Persons with AIDS: They are almost 300 times more likely to get listeriosis than people with normal immune systems.
  • Persons who take glucocorticosteroid medications (such as cortisone)
  • The elderly [11, 20, 21]

 Symptoms of Listeria infection

When a person is infected and develops symptoms of Listeria infection, the resulting illness is called listeriosis. [4, 11, 18] Only a small percentage of persons who ingest Listeria fall ill or develop symptoms. [18] For those who do develop symptoms as a result of their infection, the resulting illness is either mild or quite severe—sometimes referred to as a “bimodal distribution of severity.” [13, 28]

On the mild end of the spectrum, listeriosis usually consists of the sudden onset of fever, chills, severe headache, vomiting, and other influenza-type symptoms. [18, 28]  Along these same lines, the CDC notes that infected individuals may develop fever, muscle aches, and sometimes gastrointestinal symptoms such as nausea or diarrhea. [11] When present, the diarrhea usually lasts 1-4 days (with 42 hours being average), with 12 bowel movements per day at its worst. [18]

Most healthy adults and children who consume contaminated food experience only mild to moderate symptoms. The infection is usually self-limited, since, in healthy hosts, exposure to Listeria stimulates the production of tumour necrosis factor and other cytokines, which activate monocytes and macrophages to eradicate the organism.  Few people with normal immune function go on to have more severe, life-threatening forms of listeriosis, characterized by septic shock, meningitis and encephalitis. [4]

As already noted, when pregnant, women have a mildly impaired immune system that makes them susceptible to Listeria infection. [19] If infected, the illness appears as an acute fever, muscle pain, backache, and headache. [18, 24] Illness usually occurs in the third trimester, which is when immunity is at its lowest. [18] Infection during pregnancy can lead to premature labor, miscarriage, infection of the newborn, or even stillbirth. [24, 28] Twenty-two percent of such infections result in stillbirth or neonatal death. [18]

Newborns may present clinically with early-onset (less than 7 days) or late-onset forms of infection (7 or more days). [3] Those with the early-onset form are often diagnosed in the first 24 hours of life with sepsis (infection in the blood). [3, 18] Early-onset listeriosis is most often acquired through trans-placental transmission. [18, 24] Late-onset neonatal listeriosis is less common than the early-onset form. [4, 18, 24] Clinical symptoms may be subtle and include irritability, fever and poor feeding. [24] The mode of acquisition of late-onset listeriosis is poorly understood. [18, 24]

Diagnosis and Treatment of Listeria Infections

Because there are few symptoms that are unique to listeriosis, doctors must consider a variety of potential causes for infection, including viral infections (like flu), and other bacterial infections that may cause sepsis or meningitis. [4, 18, 19]

Early diagnosis and treatment of listeriosis in high-risk patients is critical, since the outcome of untreated infection can be devastating. This is especially true for pregnant women because of the increased risk of spontaneous abortion and preterm delivery. Depending on the risk group, rates of death from listeriosis range from 10% to 50%, with the highest rate among newborns in the first week of life. [4]

Methods typically used to identify diarrhea-causing bacteria in stool cultures interfere or limit the growth of Listeria, making it less likely to be identified and isolated for further testing. [18] On the other hand, routine methods are effective for isolating Listeria from spinal fluid, blood, and joint fluid. [4, 18] Magnetic-resonance imaging (MRI) is used to confirm or rule out brain or brain stem involvement. [18]

Listeriosis is usually a self-limited illness—which means that a majority of infected individuals will improve without the need for medical care. [4, 11, 14, 18] But for those patients with a high fever, a stool culture and antibiotic-treatment may be justified for otherwise healthy individuals. [4, 18] Although there have been no studies done to determine what drugs or treatment duration is best, ampicillin is generally considered the “preferred agent.” [18] There is no consensus on the best approach for patients who are allergic to penicillins. [18]

Invasive infections with Listeria can be treated with antibiotics. [18] When infection occurs during pregnancy, antibiotics given promptly to the pregnant woman can often prevent infection of the fetus or newborn. [18, 24] Babies with listeriosis receive the same antibiotics as adults, although a combination of antibiotics is often used until physicians are certain of the diagnosis.

Complications of Listeria infection

For those persons who suffer a Listeria infection that does not resolve on its own, the complications (or sequelae) can be many. [4, 28] The most common is septicemia (bacterial pathogens in the blood, also known as bacteremia), with meningitis being the second most common. [4, 18] Other complications can include inflammation of the brain or brain stem (encephalitis), brain abscess, inflammation of the heart-membrane (endocarditis), and localized infection, either internally or of the skin. [18]

Death is the most severe consequence of listeriosis, and it is tragically common. [3] For example, based on 2009 FoodNet surveillance data, 89.2% of Listeria patients ended up in the hospital, the highest hospitalization rate for pathogenic bacterial infection. [10] In persons 50 years of age and older, there was a 17.5% fatality rate—also the highest relative to other pathogens. [10, 18]

The Economic Impact of Listeria Infections

The USDA Economic Research Service (ERS) published its first comprehensive cost estimates for sixteen foodborne bacterial pathogens in 1989. [22] Five years later, it was estimated that, in 1993, there were 1,795 to 1,860 Listeria infections that required hospitalization, with 295-360 of these cases involving pregnant women. [28] Based on these estimates, the medical costs that Listeria infections had caused each year were said to run from $61.7 to $64.8 million, including those individuals who ultimately died as a result of their infections. [28] For these same acute cases, productivity costs were estimated to run from $125.8 to $154.4 million a year. [28] The productivity costs associated with Listeria-related chronic illness was estimated to be an additional $38 million a year. [28] In sum, “[e]stimates of total costs for the 1,795 to 1,860 cases of listeriosis range from $232.7 million to $264.4 million annually.” [28]

In 2000, USDA updated the cost-estimates for four pathogens:  Campylobacter, Salmonella, E. coli O157:H7, and Listeria monocytogenes. [28] The 2000 estimates were based on the CDC’s then newly-released estimates of annual foodborne illnesses, and put the total cost in the United States for these four pathogens at $6.5 billion a year. [28a] For Listeria specifically, it was estimated that costs amounted to $2.3 billion per year, based on 2,493 cases, which involved 2,298 hospitalizations and 499 deaths. [28] More recently, in 2007, it was estimated that the worldwide cost of all foodborne disease was $1.4 trillion per year. [6]

Real Life Impacts of Listeria Infection

Because Listeria infection is most severe in elderly persons, pregnant women and newborns, the symptoms of infection vary greatly:

  • In older adults or immunocompromised individuals, septicemia (Listeria bacteria in the blood stream) and meningitis are the most common indicators of illness.
  • In pregnant women, a mild, flu-like illness can be followed by miscarriage, premature delivery or stillbirth.
  • In newborns, bacteremia (Listeria bacteria in the blood stream) and meningitis are the most common indicators of Listeria infection.

 Antimicrobial Resistance in Bacteria

Antimicrobial resistance in bacteria is an emerging and increasing threat to human health. [1, 4] Physicians are increasingly aware that antimicrobial resistance is increasing in foodborne pathogens and that, as a result, patients who are prescribed antibiotics are at increased risk for acquiring antimicrobial-resistant foodborne infections. [1] Indeed, “increased frequency of treatment failures for acute illness and increased severity of infection may be manifested by prolonged duration of illness, increased frequency of bloodstream infections, increased hospitalization or increased mortality.” [3]

The use of antimicrobial agents in the feed of food animals is estimated by the FDA to be over 100 million pounds per year. [4] It is estimated that 36% to 70% of all antibiotics produced in the United States are used in a food animal feed or in prophylactic treatment to prevent animal disease. [3, 4, 18] In 2002, the Minnesota Medical Association published an article by David Wallinga, M.D., M.P.H. who wrote:

According to the [Union of Concerned Scientists], 70 percent of all the antimicrobials used in the United States for all purposes—or about 24.6 million pounds annually—are fed to poultry, swine, and beef cattle for nontherapeutic purposes, in the absence of disease. Over half are “medically important” antimicrobials; identical or so closely related to human medicines that resistance to the animal drug can confer resistance to the similar human drug. Penicillin, tetracycline, macrolides, streptogramins, and sulfonamides are prominent examples. [33]

The use of antibiotics in feed for food animals, on animals prophylactically to prevent disease, and the use of antibiotics in humans unnecessarily must be reduced. [1, 25] European countries have reduced the use of antibiotics in animal feed and have seen a corresponding reduction in antibiotic-resistant illnesses in humans. [1, 4]

The Prevention of Listeria infection

Given its widespread presence in the environment, and the fact that the vast majority of Listeria infections are the result of consuming contaminated food or water, preventing illness and death is necessarily (and understandably) a food safety issue.

Listeria monocytogenes presents a particular concern with respect to food handling because it can grow at refrigerator temperatures (4°C to 10°C), temperatures commonly used to control pathogens in foods. Freezing also has little detrimental effect on the microbe. Although pasteurization is sufficient to kill Listeria, failure to reach the desired temperature in large packages can allow the organism to survive. Food can also be contaminated after processing by the introduction of unpasteurized material, as happens during the preparation of some cheeses. Listeria can also be spread by contact with contaminated hands, equipment and counter tops. [4]

The use of irradiation to reduce Listeria to safe levels in foods has many proponents. [26] As noted by an eminent CDC researcher, Robert V. Tauxe:

Ready-to-eat meats, such as hot dogs, have already been subjected to a pathogen-killing step when the meat is cooked at the factory, so contamination is typically the result of in-plant contamination after that step. Improved sanitation in many plants has reduced the incidence of infection by half since 1986, but the risk persists, as illustrated by a large hot dog-associated outbreak that occurred in 1999. Additional heat treatment or irradiation of meat after it is packaged would eliminate Listeria that might be present at that point. [26]

The CDC provides a comprehensive list of recommendations and precautions to avoid becoming infected with Listeria, which are as follows:

  • Thoroughly cook raw food from animal sources, such as beef, pork, or poultry to a safe internal temperature. For a list of recommended temperatures for meat and poultry, visit http://www.fsis.usda.gov/PDF/IsItDoneYet_Magnet.pdf.
  • Rinse raw vegetables thoroughly under running tap water before eating.
  • Keep uncooked meats and poultry separate from vegetables and from cooked foods and ready-to-eat foods.
  • Do not drink raw (unpasteurized) milk, and do not eat foods that have unpasteurized milk in them.
  • Wash hands, knives, countertops, and cutting boards after handling and preparing uncooked foods.
  • Consume perishable and ready-to-eat foods as soon as possible.

Recommendations for persons at high risk, such as pregnant women and persons with weakened immune systems, in addition to the recommendations listed above, include:

  • Meats
  • Do not eat hot dogs, luncheon meats, cold cuts, other deli meats (e.g., bologna), or fermented or dry sausages unless they are heated to an internal temperature of 165°F or until steaming hot just before serving.
  • Avoid getting fluid from hot dog and lunch meat packages on other foods, utensils, and food preparation surfaces, and wash hands after handling hot dogs, luncheon meats, and deli meats.
  • Do not eat refrigerated pâté or meat spreads from a deli or meat counter or from the refrigerated section of a store. Foods that do not need refrigeration, like canned or shelf-stable pâté and meat spreads, are safe to eat. Refrigerate after opening.
  • Cheeses
  • Do not eat soft cheese such as feta, queso blanco, queso fresco, brie, Camembert, blue-veined, or panela (queso panela) unless it is labeled as made with pasteurized milk. Make sure the label says, “MADE WITH PASTEURIZED MILK.”
  • Seafood
  • Do not eat refrigerated smoked seafood, unless it is contained in a cooked dish, such as a casserole, or unless it is a canned or shelf-stable product. Refrigerated smoked seafood, such as salmon, trout, whitefish, cod, tuna, and mackerel, is most often labeled as “nova-style,” “lox,” “kippered,” “smoked,” or “jerky.” These fish are typically found in the refrigerator section or sold at seafood and deli counters of grocery stores and delicatessens. Canned and shelf stable tuna, salmon, and other fish products are safe to eat.

Recommendations to keep food safe:

  • Be aware that Listeria monocytogenes can grow in foods in the refrigerator. Use an appliance thermometer, such as a refrigerator thermometer, to check the temperature inside your refrigerator. The refrigerator should be 40°F or lower and the freezer 0°F or lower.
  • Clean up all spills in your refrigerator right away–especially juices from hot dog and lunch meat packages, raw meat, and raw poultry.
  • Clean the inside walls and shelves of your refrigerator with hot water and liquid soap, then rinse.
  • Divide leftovers into shallow containers to promote rapid, even cooling. Cover with airtight lids or enclose in plastic wrap or aluminum foil. Use leftovers within 3 to 4 days.
  • Use precooked or ready-to-eat food as soon as you can. Do not store the product in the refrigerator beyond the use-by date; follow USDA refrigerator storage time guidelines:
  • Hot Dogs – store opened packages no longer than 1 week and unopened packages no longer than 2 weeks in the refrigerator.
  • Luncheon and Deli Meat – store factory-sealed, unopened packages no longer than 2 weeks. Store opened packages and meat sliced at a local deli no longer than 3 to 5 days in the refrigerator. [11]

Additional preventive steps and precautions can be found on the websites of most State Departments of Health, including, for example, the Minnesota Department of Health. [20] There is also excellent information to be found at the Extension Service website of the Institute of Food and Agricultural Sciences at University of Florida. [27]

References (more…)

Class 1 Listeria Recall – Ready Pac Chicken Salad

Screen Shot 2017-02-22 at 3.37.18 PMThree Ready Pac Foods Inc. establishments, located in Swedesboro, N.J., in Jackson, Ga., and the headquarters establishment in Irwindale, Calif., are recalling approximately 59,225 pounds of one variety of chicken salad product that may be adulterated with Listeria monocytogenes, the U.S. Department of Agriculture’s Food Safety and Inspection Service (FSIS) announced today.

The Puro Picante Blazin’ Hot salad items were produced between Jan. 17, 2017 and Feb. 17, 2017. The following products are subject to recall:

  • 7.5-oz. single serve salad bowl packages of “Ready Pac Foods Puro Picante Blazin Hot” with Use By Dates of 01/31/17 through 03/04/2017.

The products subject to recall bear establishment number P-27497, P-32081, or P-18502B inside the USDA mark of inspection. These items were shipped to retail locations nationwide.

The problem was discovered on Feb. 21, 2017 when the firm received notification from the cheese supplier that the cheese ingredient utilized in the chicken salad products was included in an expanded cheese recall due to potential contamination with L. monocytogenes. There have been no confirmed reports of adverse reactions due to consumption of these products.

Consumption of food contaminated with L. monocytogenes can cause listeriosis, a serious infection that primarily affects older adults, persons with weakened immune systems, and pregnant women and their newborns. Less commonly, persons outside these risk groups are affected.

Listeriosis can cause fever, muscle aches, headache, stiff neck, confusion, loss of balance and convulsions sometimes preceded by diarrhea or other gastrointestinal symptoms. An invasive infection spreads beyond the gastrointestinal tract. In pregnant women, the infection can cause miscarriages, stillbirths, premature delivery or life-threatening infection of the newborn. In addition, serious and sometimes fatal infections can occur in older adults and persons with weakened immune systems. Listeriosis is treated with antibiotics. Persons in the higher-risk categories who experience flu-like symptoms within two months after eating contaminated food should seek medical care and tell the health care provider about eating the contaminated food.

FSIS and the company are concerned that some of this recalled product may be in consumers’ refrigerators.

Consumers who have purchased these products are urged not to consume them.

Hepatitis A Class Action Settled

The following release was issued today by The Notice Company, Inc.:

A Settlement has been reached in the lawsuit entitled Cody Werkmeister v. Hardee’s Restaurants, LLC, Case No. 2015-CP-42-3982, pending in the Court of Common Pleas in the Seventh Judicial Circuit Court of Spartanburg County, South Carolina, concerning alleged exposure to the Hepatitis A virus.

What is This Case About?

On September 18, 2015, the South Carolina Department of Health and Environmental Control (“Health Department”) announced that customers who ate at two Hardee’s Restaurants in Spartanburg County might have been exposed to the hepatitis A virus (“HAV”). One restaurant location was at 12209 Greenville Highway in Lyman, South Carolina, and the second location was at 1397 East Main Street in Duncan, South Carolina. The Health Department recommended that persons who ate at either the Hardee’s Restaurant in Duncan between September 4 and 13, 2015 or the Hardee’s Restaurant in Lyman between September 4 and 15, 2015, be vaccinated.  These time periods are referred to as the “Exposure Period”.

Who is Included in the Settlement?

Included in the Settlement are all persons who:

(1) consumed food or drink between September 4 and September 13, 2015, at the Hardee’s Restaurant located in Duncan, South Carolina, or between September 4 and September 15, 2015, at the Hardee’s Restaurant located in Lyman, South Carolina, and
(2) subsequently obtained a Hepatitis-A Virus (“HAV”) vaccination, an immune globulin (“IG”) shot, or HAV blood test within thirty days after eating at these Hardee’s Restaurant locations, but in no event later than October 15, 2015.

The South Carolina Department of Health and Environmental Control has not provided notice that any persons developed HAV infections after consuming food or drink at these Hardee’s Restaurant locations during these time periods; such persons, if any, are excluded from the class.  Employees of Hardee’s Restaurants are also excluded from the class.

What Does the Settlement Provide?

Each member of the Settlement Class who submits a timely, qualified claim will share equally in the aggregate Class Award of $500,000.00.

How Do You Make a Claim?

To make a claim, you must submit a Claim Form so that the Claims Administrator receives it no later than March 30, 2017. If you did not receive a Claim Form in the mail, you can obtain a Claim Form online at www.SpartanburgHepa.com, by calling 1-800-352-1270, or by writing to the Claims Administrator at:

Spartanburg Hep-A Class Action
c/o The Notice Company
P. O. Box 455
Hingham, MA 02043

Who Represents You?

The Court has appointed Marler Clark, LLP, PS, as the Class Counsel. Class Counsel will receive as attorneys’ fees 25% of the amount paid to the entire Settlement Class for general damages, or what is awarded by the Court, whichever is less. The defendant, Hardee’s Restaurants, LLC, will pay the determined Class Counsels’ fees and costs.  The Class Award of $500,000.00 will not be reduced by these attorneys’ fees and costs.

What Are Your Options?

Submit a Claim:  If you want to participate in the Settlement and receive a portion of the Class Award, you must make a claim as described above.

Exclude Yourself:  If you do not want to be legally bound by the Settlement, you must exclude yourself in writing by sending a written request for exclusion to the Claims Administrator so that it is postmarked by March 30, 2017, or you will not be able to sue, or continue to sue, Hardee’s Restaurants, LLC, about the legal claims in this case.  An exclusion request must include your name and address, state “I request exclusion from the Hardee’s HEP-A Settlement in Spartanburg County, SC”, be signed by you or your legal representative, and be mailed to:

Spartanburg Hep-A Class Exclusions
c/o The Notice Company
P. O. Box 455
Hingham, MA 02043

If you exclude yourself you may not submit a Claim Form and you will not be entitled to share in the Class Award.

Object:  If you stay in the Settlement Class, you may object to the Settlement by filing with the Court, with copies to Class Counsel and to counsel for Hardee’s Restaurants, LLC, a notice of intent to appear and/or object, no later than March 30, 2017.

Court Address:
The Court of Common Pleas of Spartanburg County
180 Magnolia Street
Spartanburg, SC 29306

Class Counsel Address:
William D. Marler, Esquire
1012 First Avenue, Fifth Floor
Seattle, WA 98104-1008

Defendant’s Counsel Address:
Kenneth W. Ward, Esq.
P.O. Box 51450
Knoxville, TN 37950-1450

The Court of Common Pleas of Spartanburg County will hold a Final Approval Hearing at 10:00 a.m. on Monday, April 17, 2017, at 180 Magnolia Street, Spartanburg, SC 29306.  At the hearing, the Court will consider whether the proposed settlement should be granted final approval as fair, adequate, and reasonable, and in the best interests of the Settlement Class as a whole.  The Parties will request that the Court enter a Final Approval Order. You may attend this hearing if you wish, but you are not required to do so in order to participate in the Settlement.

This Notice is only a Summary. To obtain a copy of the detailed Notice of Settlement, you may visit www.SpartanburgHepa.com, call 1-800-352-1270 or write to the Claims Administrator at the above address.  You may also write to Class Counsel.


Genki Sushi Scallops Hepatitis A Outbreak in Hawaii

On August 15, 2016, the Hawaii Department of Health (HDOH) identified raw scallops served at Genki Sushi restaurants on Oahu and Kauai as a likely source of an ongoing hepatitis A outbreak. The product of concern was identified to be Sea Port Bay Scallops (Wild Harvest, Raw Frozen) that originated in the Philippines (states “Product of the Philippines” on the box) and were distributed by Koha Oriental Foods.

As a result, HDOH ordered this product embargoed (not to be sold, purchased, or consumed) throughout the state, and the temporary closure of all Genki Sushi restaurants on Oahu and Kauai.

As of November 30, 2016, HDOH has identified 292 cases of hepatitis A. Seventy-four have required hospitalization. Findings of the investigation suggest that the source of the outbreak is focused on Oahu. Eleven individuals are residents of the islands of Hawaii, Kauai, or Maui, and seven visitors have returned to the mainland or overseas. Onset of illness has ranged between June 12, 2016 and October 9, 2016.

The FDA and CDC are supporting the HDOH in the investigation of hepatitis A virus (HAV) infections linked to scallops supplied by Sea Port Products Corp. On August 17, 2016, the FDA, HDOH, CDC, and state partners informed Sea Port Products Corp. that epidemiological, laboratory, and traceback information indicated that their scallops are the likely source of illnesses. On August 18, 2016, Sea Port Products Corp. initiated a voluntary recall of three lots of frozen Bay Scallops produced on November 23 and 24, 2015. The lot numbers for the recalled scallops are 5885, 5886, and 5887. The products were distributed to California, Hawaii, and Nevada. According to Sea Port Products Corp., the recalled products are not intended for retail sale. The FDA is working with the recalling firm to ensure their recall is effective and that recalled product is removed from the market.

The FDA’s traceback investigation involved working with HDOH to trace the path of food eaten by those made ill back to a common source. The traceback investigation determined that Sea Port Products Corp. imported the scallops that were later supplied to certain Genki Sushi locations in Hawaii, where ill people reported eating.

On August 17, 2016, FDA laboratory analysis of two scallop samples, which were collected on August 11, 2016, were confirmed positive for hepatitis A. These samples were imported by Sea Port Products Corp. and were produced on November 23 and 24, 2015.

The Hepatitis A Virus

Exposure to hepatitis A virus (“HAV”) can cause an acute infection of the liver that is typically mild and resolves on its own.[1] The symptoms and duration of illness vary a great deal, with many persons showing no symptoms at all.[2] Fever and jaundice are two of the symptoms most commonly associated with HAV infection.[3]

Throughout history, hepatitis infections have plagued humans. The “earliest accounts of contagious jaundice are found in ancient China.”[4] According to the CDC:

The first descriptions of hepatitis (epidemic jaundice) are generally attributed to Hippocrates.  Outbreaks of jaundice, probably hepatitis A, were reported in the 17th and 18th centuries, particularly in association with military campaigns.  Hepatitis A (formerly called infectious hepatitis) was first differentiated epidemiologically from hepatitis B, which has a long incubation period, in the 1940s.  Development of serologic tests allowed definitive diagnosis of hepatitis B.  In the 1970s, identification of the virus, and development of serologic tests helped differentiate hepatitis A from other types of non-B hepatitis.[5]

Until 2004, HAV was the most frequently reported type of hepatitis in the United States. In the pre-vaccine era, the primary methods used for preventing HAV infections were hygienic measures and passive protection with immune globulin (IG). Hepatitis A vaccines were licensed in 1995 and 1999. These vaccines provide long-term protection against HAV infection.[6]

Hepatitis A is the only common vaccine-preventable foodborne disease in the United States.[7] This virus is one of five human hepatitis viruses that primarily infect the human liver and cause human illness.[8] Unlike hepatitis B and C, hepatitis A does not develop into chronic hepatitis or cirrhosis, which are both potentially fatal conditions.[9] Nonetheless, infection with the hepatitis A virus (HAV) can lead to acute liver failure and death.[10]

Where does Hepatitis A Come From?

Hepatitis A is a communicable (or contagious) disease that often spreads from person to person.[11] Person-to-person transmission occurs via the “fecal-oral route,” while all other exposure is generally attributable to contaminated food or water.[12] Food-related outbreaks are usually associated with contamination of food during preparation by a HAV-infected food handler.[13] The food handler is generally not ill because the peak time of infectivity—that is, when the most virus is present in the stool of an infected individual—occurs two weeks before illness begins.[14]

Fresh produce contaminated during cultivation, harvesting, processing, and distribution has also been a source of hepatitis A.[15] In 1997, frozen strawberries were the source of a hepatitis A outbreak in five states.[16] Six years later, in 2003, fresh green onions were identified as the source of a HAV outbreak traced to consumption of food at a Pennsylvania restaurant.[17] Other fruits and vegetables, such as blueberries and lettuce, have also been associated with HAV outbreaks in the U.S. as well as in other developed countries.[18] HAV is relatively stable and can survive for several hours on fingertips and hands and up to two months on dry surfaces.[19] The virus can be inactivated by heating to 185°F (85°C) or higher for one minute, or disinfecting surfaces with a 1:100 dilution of household bleach in tap water.[20] HAV can still be spread from cooked food if it is contaminated after cooking.[21]

Although ingestion of contaminated food is a common means of spread for HAV, it may also be spread by household contact among families or roommates, sexual contact, or by direct inoculation from persons sharing illicit drugs.[22] Children are often asymptomatic, or have unrecognized infections, and can pass the virus through ordinary play, unknown to their parents, who may later become infected from contact with their children.[23]

What are the Symptoms of Hepatitis A?

Hepatitis A may cause no symptoms at all when it is contracted, especially in children.[24] Asymptomatic individuals will only know they were infected (and have become immune, given that you can only get hepatitis A once) by getting a blood test later in life.[25] Approximately 10 to 12 days after exposure, HAV is present in blood and is excreted via the biliary system into the feces.[26] Although the virus is present in the blood, its concentration is much higher in feces.[27] HAV excretion begins to decline at the onset of clinical illness, and decreases significantly by 7 to 10 days after onset of symptoms.[28] Most infected persons no longer excrete virus in the feces by the third week of illness. Children may excrete HAV longer than adults.[29]

Seventy percent of HAV infections in children younger than six years of age are asymptomatic; in older children and adults, infection tends to be symptomatic with more than 70% of those infected developing jaundice.[30] Symptoms typically begin about 28 days after contracting HAV, but can begin as early as 15 days or as late as 50 days after exposure.[31] The symptoms include muscle aches, headache, anorexia (loss of appetite), abdominal discomfort, fever, and malaise.[32]

After a few days of typical symptoms, jaundice (also termed “icterus”) sets in.[33] Jaundice is a yellowing of the skin, eyes, and mucous membranes that occurs because bile flows poorly through the liver and backs up into the blood.[34] The urine will also turn dark with bile and the stool light or clay-colored from lack of bile.[35] When jaundice sets in, initial symptoms such as fever and headache begin to subside.[36]

In general, symptoms usually last less than two months, although 10% to 15% of symptomatic persons have prolonged or relapsing disease for up to 6 months.[37] It is not unusual, however, for blood tests to remain abnormal for six months or more.[38] The jaundice so commonly associated with HAV can also linger for a prolonged period in some infected persons, sometimes as long as eight months or more.[39] Additionally, pruritus, or severe “itchiness” of the skin, can persist for several months after the onset of symptoms. These conditions are frequently accompanied by diarrhea, anorexia, and fatigue.[40]

Relapse is possible with hepatitis A, typically within three months of the initial onset of symptoms.[41] Although relapse is more common in children, it does occur with some regularity in adults.[42] The vast majority of persons who are infected with hepatitis A fully recover, and do not develop chronic hepatitis.[43] Persons do not carry HAV long-term as with hepatitis B and C.[44]

Fulminant Hepatitis A

Fulminant hepatitis A, or acute liver failure, is a rare but devastating complication of HAV infection.[45] As many as 50% of individuals with acute liver failure may die or require emergency liver transplantation.[46] Elderly patients and patients with chronic liver disease are at higher risk for fulminant hepatitis A.[47] In parallel with a declining incidence of acute HAV infection in the general population, however, the incidence of fulminant HAV appears to be decreasing.[48]

HAV infects the liver’s parenchymal cells (internal liver cells).[49] Once a cell has been penetrated by the viral particles, the hepatitis A releases its own toxins that cause, in essence, a hostile takeover of the host’s cellular system.[50] The cell then produces new viral components that are released into the bile capillaries or tubes that run between the liver’s parenchymal cells.[51] This process results in the death of liver cells, called hepatic necrosis.[52]

The fulminant form of hepatitis occurs when this necrotic process kills so many liver cells—upwards of three-quarters of the liver’s total cell count—that the liver can no longer perform its job.[53] Aside from the loss of liver function, fulminant hepatic failure can lead to encephalopathy and cerebral edema.[54] Encephalopathy is a brain disorder that causes central nervous system depression and abnormal neuromuscular function.[55] Cerebral edema is a swelling of the brain that can result in dangerous intracranial pressure.[56] Intracranial hypertensions leading to a brain stem death and sepsis with multiple organ failure are the leading causes of death in individuals with fulminant hepatic failure.[57]

Incidence of Hepatitis A Infection

Hepatitis A is much more common in countries with underdeveloped sanitation systems and, thus, is a risk in most of the world.[58] An increased transmission rate is seen in all countries other than the United States, Canada, Japan, Australia, New Zealand, and the countries of Western Europe.[59] Nevertheless, infections continue to occur in the United States, where approximately one-third of the population has been previously infected with HAV.[60]

Each year, approximately 30,000 to 50,000 cases of hepatitis A occur in the United States.[61] Historically, acute hepatitis A rates have varied cyclically, with nationwide increases every 10 to 15 years.[62] The national rate of HAV infections has declined steadily since the last peak in 1995.[63] Although the national incidence—1.0 case per 100,000 population—of hepatitis A was the lowest ever recorded in 2007, it is estimated that asymptomatic infections and underreporting kept the documented incidence-rate lower than it actually is. In fact, it is estimated that there were 25,000 new infections in 2007.[64]

In 2007, the CDC reported a total of 2,979 acute symptomatic cases of HAV.[65] Of these, information about food and water exposure was known for 1,047 cases, leading to an estimate that 6.5% of all infections were caused by exposure to contaminated water or food.[66] In 2,500 of the cases, no known risk factor was identified.[67]

Hepatitis A outbreaks associated with shellfish, worldwide, from 1956 to 2016. Adapted and expanded from Richards et al., 1985, Portnoy et al., 1975, and Fiore et al., 2004. Outbreaks that were poorly investigated or had fewer than 30 cases were omitted.  Italics indicate the seafood was locally sourced with respect to the cases.

Hepatitis A outbreaks associated with shellfish, worldwide, from 1956 to 2016
Year # Cases Implicated food Location of cases Source of implicated food Suspected cause of contamination Reference
1956 629 Oysters Sweden Havstenssund Harbor, Sweden Oysters stored in polluted water Roos, 1956[68]; Pintó et al., 2009[69]; Portnoy et al., 1975[70]
1961 80


Oysters Mississippi, Alabama Pascagoula River, Mississippi Polluted harvesting areas Mason and McLean, 1962*[71]
1961 459 Clams New Jersey Raritan Bay, New Jersey Polluted harvesting areas Dougherty and Altman, 1962*[72]
1964 123 Clams Connecticut Multiple US sources, primarily Rhode Island Unknown Ruddy et al., 1969[73]
1973 281 Oysters Texas, Georgia, Louisiana Louisiana Stormwater runoff; investigated possible illegal harvesting Mackowiak et al., 1976[74]; Portnoy et al., 1975[75]
1980 312 Oysters Singapore Philippines Suspect contaminated harvesting waters Lee et al., 2011[76]; Goh, 1981[77]
1981 132 Cockles, whelks, mussels, prawns Southeast England United Kingdom Sewage discharge near harvesting beds, insufficient processing O’Mahoney et al., 1983[78]
1982 225 Oysters Hondo City, Japan Ariake Bay, Japan Unknown Fujiyama et al., 1985[79]
1984 75 Mussels and clams Livorno, Italy Livorno, Italy; Venice, Italy Sewage discharge near harvesting beds, improper handling at point of sale Mele et al., 1989[80]
1988 61 Oysters Alabama, Georgia, Florida, Tennessee, Hawaii Florida Untreated sewage from residents and boats, possible illegal harvesting Descenclos et al., 1991[81]
1988 292,301 Clams Shanghai, China Qi-Dong, China Untreated sewage Halliday et al., 1991[82]
1992 800 Raw shellfish Western France Loire-Atlantique and Morbihan, France Unknown Apaire-Marchais et al., 1995[83]
1996, 1997 5673,


Mussels and clams Puglia, Italy Italy Unknown Chironna et al., 2002[84]
1997 444


Oysters New South Wales, Australia Wallis Lake, Australia Untreated sewage; stormwater runoff Conaty et al., 2000[85]
1999 184 Coquina clams Valencia, Spain Peru Unknown Sanchez et al., 2002[86]; Bosch et al., 2001[87]
1999 32 Raw shellfish Bretagne, France Bay of Pampiol, France Unknown, harvesting sites near a busy tourist port Costa-Mattioli et al., 2000[88]
2004 882 Mussels and clams Campania, Italy Primarily Campania, also other areas of Italy, Turkey Illegal storage of shellfish in contaminated seawater at point of purchase Pontrelli et al., 2008[89]
2005 39 Oysters Alabama, Florida, South Carolina, Tennessee Louisiana Untreated sewage, possibly from recreational and other boats Bialek et al., 2007[90]; Shieh et al., 2007[91]
2007 111 Oysters Côtes d’Armor, France Côtes d’Armor, France Suspect contaminated water in tanks used on a shellfish farm, nearby untreated sewage Guillois-Bécel et al., 2009[92]
2008 100 Coquina clams Spain Peru Unknown Pintó et al., 2009[93]; Polo et al., 2010[94]
2013 117 Suspect raw foods, especially seafood Taiwan Unknown Unknown Lung and Kay, 2013[95]
2014 30 Raw bivalves: oysters, clams Taiwan Unknown Unknown Taiwan CDC, 2014[96]
2016 292 Scallops Hawaii Philippines Unknown CDC, 2016[97]; HI DOH, 2016[98]


Estimates of the annual costs (direct and indirect) of hepatitis A in the United States have ranged from $300 million to $488.8 million in 1997 dollars.[99] Nationwide, adults who become ill miss an average of 27 workdays per illness, and 11 to 22 percent of those infected are hospitalized.[100] All of these costs are entirely preventable given the effectiveness of a vaccination in providing immunity from infection.[101]

References (more…)