Food Poison Journal - Food poisoning outbreaks and litigation: surveillance and analysis

A year ago, high levels of E. coli in the Lake of the Ozarks went unreported over a busy holiday weekend, for reasons that are still debated.   The Kansas City Star eventually reported on the failure to report the issue, and the apparent cover up.   Who was to blame still depends on who you ask.  It looks like some good has come of it though, as Missouri Department of Natural Resources (DNR) now has a better reporting plan in place:

The Department of Natural Resources has overhauled the way it sends an alarm about E. coli, which the government calls a serious health hazard. Also, a task force has been formed to consider a centralized sewer district around the lake, where thousands of septic tanks overflow into the water.

Reporting E. coli levels in public swimming places is important.   E. coli is the generic term for a family bacteria that includes E. coli O157:H7, and other pathogenic forms of E. coli.   The pathogenic forms of E. coli cause severe foodpoisoning symptoms, including bloody diarrhea and abdominal cramps.  In some cases, especially in children and the elderly, it can lead to hemolytic uremic syndrome (HUS).  HUS is a potentially fatal complication that can also cause permanent kidney damage.

Despite an increased awareness of the issue, the problem with the lake continues:

Recent readings show the E. coli problem has not gone away. Bacteria continues to spike, especially after rains wash feces into the lake.  While one major beach there remains open this weekend, Public Beach 1 at Lake of the Ozarks State Park has now been closed for two weekends.

In addition, a new focus on wastewater treatment plants in Missouri has uncovered more problems, but has not led to widespread action:

Inspectors cited 208 violations at 154 treatment facilities and this spring began a second sweep. As of May 21, inspectors had gone back to 142 facilities and issued 70 additional citations.  Some facilities voluntarily cleaned up their mess, state officials said. As for the rest, only two facilities have agreed to pay a total of $2,250 in penalties pending cleanup. Two others had $5,750 in penalties that were suspended pending the outcome of their cleanup.Only 26 cases so far have been referred to Attorney General Chris Koster for further action. The rest of the cases are pending, a DNR official said.

With summer just beginning, there is hope that the new warning system will at least keep swimmers away from the known dangerous locales.

Clostridium perfringens.  Unless you're a microbiologist, doctor, or foodpoisoning lawyer, you may not have even heard of Clostridium perfringens, which is the third leading cause of foodpoisoning in the United States, and recently caused a devastating outbreak at Central Louisiana State Hospital in which 40 were sickened and 3 died after eating contaminated chicken salad.

What is it?

Clostridium perfringens is an anaerobic, Gram-positive, sporeforming rod (anaerobic means unable to grow in the presence of free oxygen). It is widely distributed in the environment and frequently occurs in the intestines of humans and many domestic and feral animals. Spores of the organism persist in soil, sediments, and areas subject to human or animal fecal pollution.

What is the illness typically like?

Perfringens food poisoning is the term used to describe the common foodborne illness caused by C. perfringens. A more serious but rare illness is also caused by ingesting food contaminated with Type C strains. The latter illness is known as enteritis necroticans or pig-bel disease.

The common form of perfringens poisoning is characterized by intense abdominal cramps and diarrhea which begin 8-22 hours after consumption of foods containing large numbers of those C. perfringens bacteria capable of producing the food poisoning toxin. The illness is usually over within 24 hours but less severe symptoms may persist in some individuals for 1 or 2 weeks. A few deaths have been reported as a result of dehydration and other complications.

Necrotic enteritis (pig-bel) caused by C. perfringens is often fatal. This disease also begins as a result of ingesting large numbers of the causative bacteria in contaminated foods. Deaths from necrotic enteritis (pig-bel syndrome) are caused by infection and necrosis of the intestines and from resulting septicemia. This disease is very rare in the U.S.

Infective dose--The symptoms are caused by ingestion of large numbers (greater than 10 to the 8th) vegetative cells. Toxin production in the digestive tract (or in test tubes) is associated with sporulation. This disease is a food infection; only one episode has ever implied the possibility of intoxication (i.e., disease from preformed toxin).

How is Clostridium perfringens illness diagnosed?

Perfringens poisoning is diagnosed by its symptoms and the typical delayed onset of illness. Diagnosis is confirmed by detecting the toxin in the feces of patients. Bacteriological confirmation can also be done by finding exceptionally large numbers of the causative bacteria in implicated foods or in the feces of patients.

What foods are most often implicated in Clostridium perfringens outbreaks?

In most instances, the actual cause of poisoning by C. perfringens is temperature abuse of prepared foods. Small numbers of the organisms are often present after cooking and multiply to food poisoning levels during cool down and storage of prepared foods. Meats, meat products, and gravy are the foods most frequently implicated.

How common is Clostridium perfringens foodpoisoning?

Perfringens poisoning is one of the most commonly reported foodborne illnesses in the U.S. There were 1,162 cases in 1981, in 28 separate outbreaks. At least 10-20 outbreaks have been reported annually in the U.S. for the past 2 decades. Typically, dozens or even hundreds of person are affected. It is probable that many outbreaks go unreported because the implicated foods or patient feces are not tested routinely for C. perfringens or its toxin. CDC estimates that about 10,000 actual cases occur annually in the U.S.

Target Populations:

Institutional feeding (such as school cafeterias, hospitals, nursing homes, prisons, etc.) where large quantities of food are prepared several hours before serving is the most common circumstance in which perfringens poisoning occurs. The young and elderly are the most frequent victims of perfringens poisoning. Except in the case of pig-bel syndrome, complications are few in persons under 30 years of age. Elderly persons are more likely to experience prolonged or severe symptoms.
 

The Clostridium perfringens outbreak that occurred in early May at Central Louisianna State Hospital was recently linked to contaminated chicken salad. 40 people were sickened in the outbreak, and three people died.  So what went wrong?  Environmental health findings--i.e. the investigation at the hospital's kitchen--have not yet been released, but the outbreak almost certainly occurred as a result of improper food handling procedures. 

Clostridium perfringens is a very common pathogen in foodpoisoning outbreaks; some estimates set clostridium perfringens as the third most common cause of foodpoisoning illnesses. Most clostridium perfringens outbreaks are ultimately linked to contaminated meat, and many such outbreaks occur after holiday meals.  The reason?  The cooking of whole fowl species, such as chicken and turkeys, that are cooled improperly after cooking.  For instance, the CDC reported on a clostridium perfringens outbreak in 2008 that occurred at a Wisconsin jail, stating as follows regarding the environmental investigation at the jail's kitchen:

On August 8, the environmental health sanitarian from the local health department met with jail kitchen supervisors and employees of the food distribution company to assess food preparation and employee health and hygiene practices. The macaroni and ground beef in the implicated casserole were cooked the day before. The sanitarian determined that food temperatures had not been obtained or recorded consistently, and documentation of cooling temperatures for both the ground beef and macaroni, where cooling from 70°F to 41°F (39°C to 23°C) is a vital step, could not be provided. An inspection of the cooler revealed improper handling and cooling of taco meat, which was being prepared for a future meal and was not implicated in this outbreak; some containers of meat were cooled with ice paddles and other containers were not. 

It has not yet been publicly disclosed how the chicken in the chicken salad at the Louisianna hospital was prepared . . . or cooled.  It is possible that the chickens were cooked whole, and cooled improperly, or that the chicken salad was cooled improperly after it was assembled.  It is unlikely that the mayonnaise, vegetables, or spices that were included in the chicken salad were contaminated prior to assembly.

Whatever the case, somehow the clostridium perfringens bacteria--more specifically, the bacterial spores that release the illness-causing toxins--in the bad chicken was allowed to grow or replicate, leading to the bacterial proliferation that was surely the cause of this widespread outbreak.  An abstract from a recent article on the growth of clostridium perfringens bacteria during improper cooling states as follows:

Many meat-based food products are cooked to temperatures sufficient to inactivate vegetative cells of Clostridium perfringens, but spores of this bacterium can survive, germinate, and grow in these products if sufficient time, temperature, and other variables exist. Because ingestion of large numbers of vegetative cells can lead to concomitant sporulation, enterotoxin release in the gastrointestinal tract, and diarrhea-like illness, a necessary food safety objective is to ensure that not more than acceptable levels of C. perfringens are in finished products. As cooked meat items cool they will pass through the growth temperature range of C. perfringens (50 to 15 degrees C). Therefore, an important step in determining the likely level of C. perfringens in the final product is the estimation of growth of the pathogen during cooling of the cooked product.

We are getting closer to finalizing www.outbreakdatabase.com.  Thanks for all the input - keep it coming.

The sprouts salmonella outbreak's case count has increased by six to 28 confirmed cases of Salmonella Newport.  AP reports as follows:

Federal officials have identified six additional cases of salmonella poisoning linked to raw alfalfa sprouts, bringing the total to 28 people sickened in 10 states.

The Centers for Disease Control and Prevention said Thursday that three more people were sickened in California, for a total of 14 cases there. Caldwell Fresh Foods of Maywood, Calif., announced a nationwide recall of its alfalfa sprouts last week.

Other new cases were found in Arizona and Idaho. Nevada, Wisconsin, Oregon, Illinois, Missouri, New Mexico and Colorado also identified cases linked to the outbreak. The sprouts were sold to more than 400 Wal-Mart stores in 15 states.