U. S. Food and Drug Administration
Center for Food Safety and Applied Nutrition
FDA Prime Connection

University of Florida - Scombroid Poisoning
 
 
                             Scombroid Poisoning
 
                   Dr. W. Steven Otwell, Seafood Specialist
                  Food Science and Human Nutrition Department
        University of Florida, IFAS Cooperative Extension Service and
              Florida Sea Grant Program with support through the
        U.S. Department of Agriculture's Cooperative Extension Service.
 
                       Sea Grant Extension Fact Sheet-12
 
 
 
This note is intended to assist the seafood industry and health professionals in
addressing a unique form of food poisoning caused by consumption of certain
marine fish species that have experienced partial bacterial spoilage. Scombroid
poisoning is not usually a severe or long-term illness, and prevention is not
difficult; yet occurrence continues about the world. The principal concern is for
fresh fish, but the intoxication can result from consumption of certain frozen,
cooked, cured or canned fish products.
 
 
What is Scombroid Poisoning?
 
Scombroid poisoning is a type of food intoxication caused by the consumption of
scombroid and scombroid-like marine fish species that have begun to spoil with
the growth of particular types of food bacteria. Fish most commonly involved are
members of the Scombridae family (tunas and mackerels), and a few non-scombridae
relatives (bluefish, dolphin or mahi-mahi, and amberjacks). A few additional
species have been implicated, but they are of less concern relative to popular
fish consumption. The suspect toxin is an elevated level of histamine generated
by bacterial degradation of substances in the muscle protein. This natural
spoilage process is thought to release additional by-products which potentiate
the toxic effect. The potential toxins are not destroyed by freezing, cooking,
smoking, curing or canning.
 
 
Where does scombroid poisoning occur?
 
Scombroid poisoning occurs wherever the particular marine fish species are eaten.
Annual reported occurrence in the United States through the last two decades has
been somewhat consistent despite the increasing popularity of fish, particularly
tuna fish. Knowledge of the causative factors and controls have directed
effective industry and regulatory responses to assure proper handling and
monitoring for the species of concern. In annual reports scombroid poisonings
still rank among the top four most often reported seafoodborne illnesses. No
doubt consumer mishandling in recreational and home settings can contribute to
the incidence, and food service establishments must be better advised in product
selection and handling.
 
 
How can one identify scombroid poisoning?
 
Confirmation for scombroid poisoning is a simple histamine analysis of the
suspect fish. A common, routine fluorometric procedure can determine milligrams
(mg) of histamine per 100 grams (g) of edible fish. Histamine concentrations near
or above 100mg/100g are typically noted in actual illnesses. Regulatory
guidelines have not been established for all the various fishes of concern, but
50mg/100g is inferred from the U.S. FDA's poisonous action level for tuna.
 
Symptoms of scombroid poisoning can become evident within minutes to 2 hours
following consumption. This rapid onset is one reason scombroid poisoning may be
reported more often than many otherfood poisonings which react much slower.
Initial signs suggest an allergic response with facial flushing and sweating,
burning-peppery taste sensations about the mouth and throat, dizziness, nausea
and headache. These initial symptoms can advance to facial rash, hives, edema,
short term diarrhea and abdominal cramps. Severe cases may blur vision, and cause
respiratory stress and swelling of the tongue. Symptoms usually last for
approximately 4 to 6 hours and rarely exceed one to two days.
 
Symptoms for scombroid poisoning can be easily confused with an allergy or other
form of food poisoning, and vice versa. For example, some symptoms for scombroid
poisoning are similar to ciguatera, another form of marine fish poisoning.
Distinguishing these illnesses can be complicated particularly about warm water
regions.
 
 
What should one do if they suspect scombroid poisoning?
 
- Consult a physician, explaining your concerns, types and amount of food eaten,
and when the symptoms began.
 
- Try to obtain portions of the meal, particularly the suspect fish. These
portions must be carefully handled, packaged and frozen to prevent any
deterioration.
 
- Try to verify the species and size of suspect fish, and how it was cooked and
handled prior to cooking.
 
Inquire where the fish came from. Knowledge of species, source and prior handling
could implicate other forms of food poisoning. Note the method or source used to
verify the species, realizing local vernaculars and menu nomenclature can be
misleading.
 
- Consult with other professionals in public health, food safety regulation or
academic research that can better advise your physician. Many physicians are not
familiar with scombroid poisoning.
 
 
What should one do to avoid scombroid poisoning?
 
Remember potential scombrotoxic fish belong to a particular group of species that
have been allowed to initially spoil. These species should always receive special
care in handling, washing, and proper icing, refrigeration or immediate freezing
to prevent bacterial growth and spoilage. Studies have demonstrated toxic
histamine levels can be generated within less than 6 to 12 hours exposure without
ice or refrigeration. This problem is of particular concern immediately after
catch aboard a commercial or recreational boat. Likewise, the recreational catch
lying on a warm dock or beach is prone to histamine production in certain
species. The adverse consequence is not severe, but discomforting and alarming
enough to warrant a little extra care. Prevention is simple and preferable to
treatment which is similar as used for allergic reactions. Common advice from
physicians includes treatments with antihistamines.
 
 
Additional References
 
Lange, W.R. 1988. Scombroid poisoning. American Family Physician 37 (4) 163-168.
Ragelis, E.P. (Ed.) 1984. Seafood Toxins [Scombroid Fish Poisoning-Chaps. 35
thru 37]. American Chemist Society, Washington, D.C. 460 pp.
Taylor, S.L. 1988. Marine toxins of microbial origin. Food Technology. 53 (3)
94-98.
 
 
Additional Advice
 
Dept. Agriculture and Consumer Affairs
Food Laboratory
3125 Conner Blvd.
Tallahassee, FL 32301
(904) 488-0670
 
Dept. Health and Rehabilitative Services
Disease Control Epidemiology Section
1317 Winewood Blvd., Bldg. 2, Room 275
Tallahassee, FL 32399-0700
(904) 488-2905
 
Dept. Natural Resources
Bureau Marine Science and Tech.
100 8th Avenue, S.E.
St. Petersburg, FL 33701
(813) 896-8626
 
University of Florida
Seafood Technology
Dept. Food Science and Human Nutrition
Gainesville, FL 32611
(904) 392-1991 or 2558
 
                                                                    (06/09/95)