The Newest Epidemic Acute Infectious Foodborne Illness

The ER physician’s note about a patient who had finished dinner in a local restaurant approximately 12 hours earlier read as follows:

The above named patient was seen in xxx Hospital April 7, 2005 and treated for Acute Foodborne Illness.

This is a new epidemic that isn’t.

At Corporate Wellness, the medical department for restaurant and foodservice groups nationally, panicked restaurant managers regularly fax notes like this to us for evaluation and follow up.

There are a number of problems with this scenario:

• Onset of symptoms generally takes at least 10-12 hours for most foodborne illness.
• Laboratory samples (and more specifically stool cultures), are required for a positive diagnosis of most infectious foodborne illness.
• Cultures take time to grow. Making a confirmed diagnosis takes several days (at best).
• Viral syndromes are very common. The symptoms may have been caused by contact with an infected person, rather than a food source.

There are some foodborne illnesses caused by viruses that may have onset before 10-12 hours, such as noroviruses, adenoviruses, and parvoviruses; but their incubation may be as long as 70 hours. Rotavirus takes from 13 days, and hepatitis A 15-55 days, averaging 14 plus days.(1) The most common cause of gastroenteritis, today, is considered to be Norovirus. If all patients suspected of foodborne illness had specimens collected, half of all foodborne outbreaks in the US could be accurately attributed to Noroviruses. Norovirus outbreaks affect almost twice as many people as bacterial outbreaks, but can be spread from person to person as well. (2)

There are several foodborne bacterial diseases with a short incubation including Bacillus Cereus (16 hours) and Staphylococcus aureus (16 hours), as well as Vibrio paraheamolyticus (2-48 hours).(1) However, these are not the most common bacteria that cause outbreaks. 69% of analyzed bacterial outbreaks are attributed to Salmonella spp. Shigella spp. Campylobacter spp and E. Coli, which have longer incubations.(2) Other bacterial illnesses take considerably longer, even to up to 30 days for Clostridium botulinum in infants.(1)

Parasitic diseases vary with the shortest incubation period of 1-2 days (Trichinella spiralis and Cyclospora cayetanensis). Others take at least 2 days including Cryptosporidium and Entamoeba histolytica. Most others take 5 to 7 days or more. (There are some non-infectious causes of foodborne illness that are much rarer, such as copper or mercury poisoning that may have a quick onset, require other specific testing, and are described in the reference below.)(1)

It is more frequently home cooking rather than restaurant food that is the culprit for food poisoning, especially for sporadic cases (those cases not associated with an outbreak). A study performed in 81 cities in the United States and Canada observed the food handling behavior of people at home. In 96% of the homes studied, there was at least one important food handling error that could have lead to a foodborne illness. (3)

The most common food handling mistakes at home are:

1. personal hygiene (not washing after bathroom use),
2. cross-contamination of unwashed kitchen equipment between use for raw chicken or meat, and produce,
3. food from unsafe sources (such as unpasteurized dairy), and
4. improper holding temperatures or rate of cooling of food.(4)

Laboratory samples (most importantly: stool cultures), are required for a diagnosis of most infectious foodborne illness. This may sound obvious, but unfortunately is not necessarily the standard routinely followed in many ERs. This is possibly because of the time required for obtaining the sample, and the frequent difficulty at arranging followup. Stool samples must be obtained, sent to a lab for analysis, planted on a medium and allowed to grow at least for 24 hours before analysis by a microbiologist. A report must be generated, transcribed and transmitted to the treating physician. Frequently, this process takes close to a week in the best of circumstances.

Empiric therapy is usually given in the ER in severe or life-threatening situations. This may occur, especially in infants, the elderly, pregnant women and immune-compromised patients. However, this probably was not the case for the patient described above who was treated and sent home from the emergency room. Treatment is best supported by an accurate diagnosis for the patient’s sake, their contacts, and the others who may have or could be exposed to a potent foodborne pathogen.

“Foodborne illness is a serious public health problem. The centers for Disease Control and Prevention (CDC) estimates that each year 76 million people get sick, more than 300,000 are hospitalized, and 5000 die as a result of foodborne illnesses annually.” (1) Unsubstantiated claims of infectious food poisoning have a potential for delayed or incorrect diagnosis and treatment for the patient, as well as negative impact on the food and restaurant industry especially the specific restaurant where the patient stated he had just eaten. Chances are more likely in this case that the patient’s symptoms are from contact with an infected person, or from foods eaten the prior day (possibly at home).

A suggested approach for patients presenting to the ER with diarrhea includes:

A.     History including description and duration of symptoms and stools.

B.     History of foods eaten (see table), travel, contacts with animals or sick people, daycare or nursing home attendance, and occupation.

C.    Physical exam.

D.    Stool culture, especially for patients with bloody, severe or persistent diarrhea or severe abdominal pain (or patient is immunocompromized).1

F.     Follow up with patient and/or local treating physician.

G.    Report suspected severe foodborne illness and proven positive cultures to local health department.

A worthwhile and more complete reference for physicians and others treating patients is the Diagnosis and Management of Foodborne Illnesses, A primer for Physicians and Other Health Care Professionals; which can be obtained from the American Medical Association 515 North State Street, Chicago, Ill 60610, 3124644147, fax: 3124645841 or email: srt@amaassn.org.

References:

1 Diagnosis and Management of Foodborne Illnesses, A primer for Physicians and Other Health Care Professionals. Litjen (L.J.) Tan, PhD (Working Group Chair). 2004 update.

2 Widdowson MA, SulkaA, Bulens SN, Beard RS, Chaves SS, Hammond R, Salehi ED, Swanson E, Totaro J, Woron R, Mead PS, Bresee JS, Monroe SS, Glass RI. Norovirus and Foodborne Disease. Emerg Infect Dis. 2005 Jan:11(1):95102.

3 Daniels RW. Home Food Safety. Food Technol 1998:52:5456.

4 Medeiros LC,Hillers VN, Kendall PA, Mason A, Food Safety Education: What should we be teaching to consumers? J Nutr Educ.2001 MarApr;33(2):10813.Review.

Judith Strauss MD is a Medical Director of Corporate Wellness and President of Strauss Partners, Westchester NY. She can be reached at jstrauss@corporatewellness.com.

Roslyn Stone MPH is the Chief Operating Office of Corporate Wellness, Westchester, NY. She can be reached at rstone@corporatewellness.com.

Table:

Common causes of Foodborne Illness:

Unpasteurized milk, juice, cheese

Fresh produce such as fruits and vegetables

Raw or poorly cooked foods such as:

Eggs, poultry, meats, fish and shellfish, sauces, creamed pastry

Home-canned foods

Untreated water

Foods contaminated by feces or infected food workers