Case Definition: Brevetoxin

Clinical description

Brevetoxins are a group of similar neurotoxic compounds which are tasteless and odorless. Although toxicity can result from inhalational, dermal, or oral exposure, the most common route of exposure is by oral ingestion of contaminated shellfish. Illness from oral ingestion is characterized by a combination of gastrointestinal and neurologic signs and symptoms. Gastrointestinal symptoms include abdominal pain, vomiting, and diarrhea. Neurologic signs and symptoms include paresthesias, reversal of hot and cold temperature sensation, vertigo, and ataxia. Inhalational exposure may cause respiratory symptoms such as cough, dyspnea and bronchospasm (1-4). Brevetoxin can also cause illness in aquatic wildlife.

Laboratory criteria for diagnosis (5-10)

• Biologic: The detection of brevitoxins or their metabolites in clinical specimens. There is limited analytical capability to detect selected brevitoxins or their metabolites in urine by immunoassay.
• Environmental: Brevetoxins can be detected in water and contaminated environmental samples by commercial laboratories using ELISA and LC-MS.

Case classification

• Suspected: A case in which a potentially exposed person is being evaluated by health-care workers or public health officials for poisoning by a particular chemical agent, but no specific credible threat exists.
• Probable: A clinically compatible case in which a high index of suspicion (credible threat or patient history regarding location and time) exists for brevetoxin exposure, or an epidemiologic link exists between this case and a laboratory-confirmed case.
• Confirmed: A clinically compatible case in which laboratory tests on environmental samples are confirmatory.

The case can be confirmed if laboratory testing was not performed because either a predominant amount of clinical and nonspecific laboratory evidence of a particular chemical was present or the etiology of the agent is known with 100% certainty.

Additional resources

1. Tunik MG. Chapter 45. Food Poisoning. In: Hoffman RS, Nelson LS, Goldfrank LR, Howland MA, Lewin NA, Flomenbaum NE, eds. Goldfrank's Toxicologic Emergencies. 9th ed. New York: McGraw-Hill; 2011.
2. Baden DG, Bourdelais AJ, Jacocks H, Michelliza S, Naar J.Natural and derivative Brevetoxins: Historical Background, Multiplicity, and Effects. Environ Health Perspect2005;113(5): 621-625.
3. Fleming LE, Kirkpatrick B, Backer LC, et al. Initial evaluation of the effects of aerosolized Florida red tide toxins (brevetoxins) in persons with asthma. Environ Health Perspect 2005;113(5):650-7.
4. Watkins SM, Reich A, Fleming LE, Hammond R. Mar Drugs 2008;6(3):431-4553. Plakas, SM and Dickey RW. Advances in Monitoring and Toxicity Assessment of Brevetoxins in Molluscan Shellfish. Toxicon 2010;56: 137-149.
5. Abraham A, Plakas SM, Flewelling LJ, El Said KR, Jester EL, Granade HR, White KD, Dickey RW. Biomarkers of Neurotoxic Shellfish Poisoning. Toxicon 2008;52: 237-245.
6. Poli MA, Musser SM, Dickey RW, Eilers PP, Hall S. Neurotoxic shellfish poisoning and brevetoxin metabolites: a case study from Florida. Toxicon 2000;38:981-93.
7. NIOSH. NIOSH manual of analytical methods [online]. 2003. [cited 2013 Apr 5]. Available from URL: http://www.cdc.gov/niosh/docs/2003-154/
8. OSHA. Sampling and analytical methods [online]. 2010. [cited 2013 Apr 5]. Available from URL: http://www.osha.gov/dts/sltc/methods/index.html.
9. FDA. Food: Laboratory methods [online]. 2013. [cited 2013 Apr 5]. Available from URL: http://www.fda.gov/Food/FoodScienceResearch/LaboratoryMethods/default.htm.
10. EPA. Selected analytical methods: chemical methods query [online]. 2013. [cited 2013 Apr 5]. Available from URL: http://www.epa.gov/sam/searchchem.htm.