[GOOD]

Hello and welcome to

“Recognition of Chemical Associated Gastrointestinal Foodborne Illness”.

I'm Cynthia Good,

your moderator for this program which is originating from the studios of the Centers for Disease Control and Prevention in Atlanta, Georgia.

This program is sponsored by the National Center for Environmental Health,

Agency for Toxic Substances and Disease Registry and CDC’s Public Health Training Network.

The goal of this program is to enhance early recognition, reporting,

and clinical management of chemical associated gastrointestinal foodborne illness by clinicians and healthcare providers.

Upon successful completion of the program,

participants will be able to:

* Distinguish features of chemical associated foodborne illness

* Describe epidemiologic clues of a covert chemical associated foodborne illness

* Describe a structured approach to guide the generation of a differential diagnosis targeting various chemical etiologies

* Describe appropriate reporting strategies for suspected covert chemical associated foodborne illness, and...

* Discuss the clinical course and general management of poisoning from various chemicals

So, now that we’ve gotten the business part of the program behind us,

let’s meet our program guests.

I’d like to welcome Dr. Helen

Schurz Rogers,

Research Scientist with the National Center for Environmental Health at CDC ...

...and Lieutenant Commander

Joshua Schier of the United States Public Health Service, Medical Toxicologist with the National Center for Environmental Health at the CDC.

Welcome to the program.

Let’s begin with you, Dr. Rogers.

[ROGERS]

Thank you, Cynthia.

The etiologies of a large majority of foodborne gastrointestinal

illness, or

GI illness outbreaks are never identified or confirmed by the laboratory.

GI illness refers to the presence of

GI signs and symptoms including nausea,

vomiting,

abdominal discomfort and diarrhea.

Chemicals are seldom considered early in the differential diagnosis of foodborne

GI illness since the majority of these illnesses in which an etiology is identified are caused by biological organisms, such as bacteria, viruses or parasites.

Since the most commonly identified etiologies of

GI foodborne illnesses are due to biological organisms, these are much more commonly considered early in an outbreak.

The wide variety of possible chemicals that can induce

GI illness hinders accurate recognition and diagnosis.

When chemicals are finally considered, biologic specimens such as urine and blood often have to be re-collected and may not show evidence of the chemical due to the body’s normal elimination mechanisms. Furthermore,

stool samples,

which are commonly used for analysis of infectious foodborne illness are often not the ideal specimen to identify chemical etiologies.

Chemical agents have been used in the deliberate contamination of food with the intention of causing illness in the past. We will discuss several examples during the course of this webcast.

Since the terrorist attacks of 2001, concern has grown about the use of chemical agents in future attacks. Contamination of the nation’s food supply is one major area of concern.

This webcast has been structured to assist clinicians and public health officials in the recognition of chemical associated GI foodborne

illness.

It is also intended to raise awareness and recognition of how many commonly available chemicals could be used in a covert chemical terrorism event. Most chemicals tend to produce

GI symptoms within a short time frame, less than 12 hours, after ingestion.

Chemicals that do not produce

GI symptoms within that time frame or those agents that do not produce

GI symptoms at all after ingestion will NOT be discussed.

No etiologic agent was identified in

62 percent of the 1073 foodborne disease outbreaks reported to the

CDC in 2003.

Many of these outbreaks had illness characterized by the onset of

GI symptoms such as nausea,

vomiting,

diarrhea and abdominal discomfort of less than 12 hours, classifying them as short incubation outbreaks.

Possible etiologic agents in these short incubation outbreaks include industrial chemicals,

drugs,

pesticides,

and plant toxins - most of which could be identified and quantified in specialized laboratories if specimens were collected and stored correctly until analysis was able to be completed. Detection of these agents,

however,

requires

agent-dependent specific biologic specimen collection,

prompt collection methods,

and testing techniques that are not routinely included in the investigation of many foodborne outbreaks.

[GOOD]

Thank you,

Dr. Rogers.

Allow me to interject some information concerning the background for this program.

This webcast will provide clinicians and public health officials with the following information related to chemical etiologies of unintentional and intentional covert chemical associated foodborne GI illness:

* background information on chemical poisoning

* the general differences between biological and chemical foodborne illnesses

* epidemiologic clues of chemical foodborne illnesses

* how to recognize a possible covert chemical terrorism foodborne poisoning event

* a structured approach to guide the generation of a differential diagnosis targeting chemical etiologies

* discussion of possible chemical etiologies and their management

AND, how to report chemical associated GI foodborne

illness.

To continue with this background information,

let’s go to Dr. Schier.

[SCHIER]

Thanks, Cynthia.

The rapid and accurate identification of a chemical etiology in foodborne illness outbreaks is necessary for many reasons.

These includeing proper patient management,

risk assessment for long-term adverse health effects and outbreak control.

In a true chemical terrorism event this is even more important.

Accurate identification of a chemical etiology in a foodborne illness outbreak is done through good investigative work, early consideration of a possible chemical etiology and prompt collection of biologic samples.

Historically,

most chemical associated foodborne

GI illnesses have been unintentional. However,

there have been several notable cases of intentional poisoning through food contamination. When an intentional poisoning occurs,

it may be overt or covert.

In an overt foodborne illness, the contamination of food is often obvious, that is,

it may have been announced in some way such as by the discovery of an overturned chemical container into foodstuffs prior to processing.

In a covert foodborne illness;

however,

it may not be immediately apparent that a food or meal is responsible for the illness.

An example of a covert event would be the intentional or inadvertent contamination of food in a restaurant with a harmful agent that is unknown to the restaurant patrons and not immediately identifiable.

The presence of ill persons at an emergency department,

or even at the restaurant,

may be the first indication of a common source of exposure.

If there is a highly suspected or known exposure,

or a concurrent credible threat of poisoning,

then a clinical diagnosis can be much more easily made.

However,

if illness is occurring as a result of a covert event,

clinical diagnosis will be much more difficult.

[GOOD]

That’s very interesting.

Could you discuss some historical examples of chemical foodborne GI illness . . . examples that would differ in scope, etiology of contamination and severity . . .

perhaps to illustrate the various ways chemical contamination of foodstuffs may occur?

[SCHIER]

Sure.

In March 2002,

a man and woman in NJ became ill after eating a meal of pufferfish they had prepared at home.

A relative had caught the fish in Florida and shared part of the catch with family.

Shortly after eating the fish,

they both began to feel tingling in the mouth and around the lips.

During the next two hours,

the woman began vomiting and experiencing chest pain.

The local poison control center was contacted and they were both advised to proceed to the closest hospital.

At the hospital,

the woman had a mild tachycardia,

an elevated blood pressure and began to develop an ascending paralysis.

A test of her respiratory function indicated she had less than 20 percent of a normal vital capacity for a woman her age.

She was electively intubated and placed on a mechanical ventilator.

Over the next several days she recovered and was able to be successfully extubated 72 hours later.

The examination of Florida state poison control center records and the national poison center reporting database back to January of 2002 indicated that these pufferfish poisoning cases were not the first.

From January to July, a total of 23 cases of pufferfish poisoning sporadically occurred in four states including,

New Jersey,

New York,

Virginia and

Florida,

although all of the fish had been harvested in Florida. Only one case was from store-bought fish;

all others were from recreational fishers.

Fish tissue specimens and urine samples from patients were collected for laboratory analysis.

Tetrodotoxin was initially considered as the etiologic agent due to its known presence in pufferfish. Tetrodotoxin was not identified in the fish tissue samples; however,

additional analysis confirmed the presence of saxitoxin.

Saxitoxin is a similar toxin that is found in certain types of shellfish.

In these cases of illness,

presumptive diagnosis of pufferfish poisoning was made based on the neurologic symptoms the patients experienced,

the latency of the symptoms and the type of food consumed.

What was important in these events, however,

was the rapid consideration and identification of the type of toxin most consistent with their symptoms.

This greatly assisted in the management and treatment of their clinical findings. Helen….

[ROGERS]

Thanks Josh.

In July 2004,

ten people reported that they became ill at a restaurant. They were not part of a large group that ate together at the restaurant,

and local hospitals did not report any rise in community illness.

Some of the people who became ill had consumed food, while others had only consumed fountain drinks.

Nausea and vomiting were the most common symptoms, and,

the average incubation period was 10 minutes.

Two people also developed diarrhea the following day.

A health inspection of the restaurant did not indicate any obvious etiologies or health code violations.

Further investigation, however,

found that seven out of the 10 cases had consumed fountain drinks.

Ice,

water and carbonated beverages from the fountain machine were collected for testing.

Test results indicated that copper was almost seven times higher in the fountain drinks than the acceptable limit for human consumption. This was ultimately determined to be the etiology of the illnesses.

Copper may leach out into the water when acidic solutions enter copper pipes.

In a post-dispensing soda machine,

like those found in fast-food restaurants, carbonation of the water occurs after the water leaves the copper piping. Regulations require a functional

back-flow prevention valve at the end of the copper-pipe. This valve prevents the carbonated water or carbonic acid from back flowing back into the copper pipe. A faulty valve canwill allow the carbonated water to enter the copper-pipe.

Leaching of the copper from the pipe may occur after prolonged contact with carbonic acid.

Most often,

the leaching occurs overnight when the dispenser is not operated;

the first users in the morning,

typically the restaurant workers, are the ones who become ill -

hence copper poisoning has been called the

“restaurant worker syndrome”.

Luckily all individuals that were affected by this contamination recovered.

Josh….

[SCHIER]

In April of 2003,

27 people stayed after church services for a council meeting.

During the meeting, refreshments, including pastries and beverages,

were served. Approximately 16 people became ill with nausea, vomiting and diarrhea after consuming

bitter-tasting coffee.

The ill parishioners were taken to an area hospital where they were evaluated. An infectious etiology was initially suspected;

however, as the clinical course of several of the ill parishioners worsened,

a possible chemical etiology was considered.

The rapid progression of illness and the failure to respond to basic supportive care prompted consultation with the New England Poison Control Center as well as the local and state health departments.

Sixteen people were ultimately hospitalized and some were seriously ill.

Even with prompt recognition and treatment of this illness,

tragically,

one person died.

The collaboration between clinicians, local and state public health officials and the poison control center targeted several likely etiologies,

including arsenic.

The identification of a clinical course which was atypical for most infectious foodborne illness and subsequent laboratory analysis for chemical agents led to the rapid identification of arsenic as the etiologic agent. Antidotal chelation therapy was then initiated in conjunction with continued supportive care.

[ROGERS]

GI illnesses can be broken down into two categories based on GI tract symptoms. These include upper GI illnesses and lower GI illnesses.

Upper GI illnesses usually include nausea and vomiting.

Lower GI illnesses usually include abdominal cramps and diarrhea.

The latency and presence of upper

GI and/or lower

GI symptoms as well as which ones occur first or predominate, are important clues in determining if a biological or chemical foodborne illness is occurring.

Although poisoning without GI symptoms may occur after consumption of some contaminated foodstuffs,

most chemicals do cause GI symptoms if significant amounts are ingested,

and only those agents will be discussed in this presentation.

In general,

infectious foodborne illnesses have mean incubation periods that are at least

12 hours long although shorter incubation periods are the norm for illness resulting from the ingestion of certain pre-formed toxins from Staphyloccus aureus and Bacillus cereus.

The incubation period,

however,

may not be definitively known until an investigation pinpoints the actual source.

Depending on the agent, upper GI or lower GI symptoms may predominate.

In chemical foodborne illnesses, symptoms may be similar to some aspects of the flu, namely the GI ones. Upper GI symptoms are more likely to predominate.

The most important indicator of chemical contamination is the latency of the illness onset,

which is often very short.

Indeed,

symptoms from many agents such as metals,

detergents and pesticides

can start within minutes of ingestion. Others such as ricin poisoning may take several hours.

Chemicals should be strongly considered in the differential diagnosis of

GI foodborne illness when:

* The latency period is very short.

Most GI manifestations of chemical illnesses will occur within

30 to 60 minutes of ingestion.

There are some exceptions,

however,

such as Amanita mushroom poisoning or ricin which may take several hours before they begin to cause symptoms...

* Symptoms do not resolve over time with standard supportive therapy, or they rapidly worsen over the next 12 to 24 hours despite this therapy...

* There are reports that the food had a metallic taste, or unusual odor or appearance...

* The predominant GI symptom is often vomiting;

however,

case-patients may have other symptoms such as neurologic findings, depending on the type of toxin.

[GOOD]

Thank you Dr. Rogers.

Those were some of the symptom clues.

Dr. Schier,

what are some examples of clinical manifestations that go along with chemical poisining?

[SCHIER]

Chemical poisoning may result in a rapid progression of illness and cause a variety of clinical manifestations and laboratory abnormalities.

Some examples include:

* Metabolic acidosis

* Hypoglycemia

* Tachycardia

* Hypotension

and...

* Tachypnea

When present,

these manifestations may occur in conjunction with multiple system organ dysfunction and rapid progression of illness that may be unresponsive to traditional therapies.

Neurologic symptoms are more indicative of a chemical or biological toxin exposure than a bacterial one.

These symptoms may include parasthesias, numbness, weakness in extremities,

visual disturbances or dizziness.

Flushing,

diaphoresis or a burning sensation may occur.

The presence of symptoms like these can be an important clue that a chemical exposure has occurred.

Similarly, organoleptic comments,

or comments that describe a quality of the food having to do with taste,

smell or visual appearance,

can be important clues.

For example:

* Did the food have an odd taste?

Was it metallic, acidic,

burning,

alcoholic or bitter? Was there an excessive amount of flavor,

such as sweet,

salty or sour?

* Were there any strange odors associated with the food,

such as a chemical or metallic odor?

* Did the food look different,

was there a strange color or texture,

was it oily or viscous?

Another factor which complicates the accurate identification of a chemical etiology is possible exposure to multiple agents.

This may result in clinical findings that do not make up an easily recognizable pattern.

Healthcare providers are generally less familiar with clinical presentations of chemical poisonings than they are with signs and symptoms resulting from infectious gastroenteritis.

The severity and duration of symptoms depends on the type and amount of exposure to a given chemical or toxin.

Depending on the toxin,

specific antidotal therapy,

supportive treatment and hospital observation may be necessary to ensure a good outcome. Helen…

[ROGERS]

Once a chemical exposure is suspected,

it’s vitally important to collect proper samples so that the agent can be identified.

This may mean that several types of samples need to be collected initially.

Laboratory analysis for a particular agent usually involves measuring the agent itself,

a metabolite or a surrogate marker.

If a chemical foodborne illness is suspected,

it is best to collect appropriate biological specimens as soon as possible and preferably within the first 24 hours.

If chemical analysis is not immediately available or the differential diagnosis is too broad to enable efficient analysis,

samples can usually be stored in a freezer.

In the laboratory workup of chemical foodborne illness, the emphasis is often placed on prompt collection of a urine specimen,

whereas in most biologic foodborne illnesses,

emphasis is placed on the collection of stool samples.

An early or first vomitus sample may sometimes be very helpful in identifying the chemical.

Some agents are also identifiable in blood samples.

Stool samples are generally not useful for identification of chemical etiologies.

Many chemicals have a short-half life, which refers to the amount of time it takes for half of a dose to be eliminated. If too much time passes before a urine sample is collected,

there won’t be enough of the agent left for identification.

It’s also important to collect urine samples from

non-symptomatic people that shared in the meal or food item.

The reason for this is that these individuals provide an important control sample that is helpful when evaluating laboratory results.

Whenever possible, samples of the implicated food or beverage should also be obtained for analysis.

Sometimes,

if a method does not exist for the laboratory confirmation of a chemical in a biological specimen, like urine,

there may be a method available that can be utilized for food samples.

Unused collection containers, preferably from the same lot, should also be stored.

These containers are used to help the laboratory evaluate for any background contamination.

It is important to also mention that collection procedures and guidelines are similar for chemical agents that do not cause early onset

GI symptoms.

A useful resource for the proper collection of biological materials is located on the CDC website.

Details about proper sample collection techniques and storage are also given.

A vital part of the investigative process in a foodborne outbreak is a standardized food history questionnaire. One of the goals of such a questionnaire is to seek commonalities among the ill.

These questions may be essential to implicate a particular foodstuff.

Once a food or meal has been implicated, pertinent questions to ask include:

* What were the predominant symptoms?

* What was the latency of illness?

* What food items were available to the patient,

which ones were consumed and how was the food prepared?

For chemical foodborne illnesses, it is helpful to keep in mind the following questions,

and then include these in the final questionnaire: