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  1. Outbreaks of Foodborne Illness

How to Report Seafood-Related Toxin and Scombrotoxin Fish Poisoning Illnesses

To help FDA effectively investigate, remove unsafe seafood products from the market, and develop new prevention strategies, the FDA relies on illness reporting from public health officials and healthcare providers. While most foodborne outbreaks are tracked through the FDA’s Coordinated Outbreak Response and Evaluation (CORE) network, seafood-related illnesses caused by natural toxins have a unique reporting mechanism. This web page provides information on commonly occurring seafood-related illnesses and how to report them to the FDA.  To report an illness from raw bivalve molluscan shellfish, email the FDA at shellfishepi@fda.hhs.gov.

The FDA receives reports of illnesses associated with the consumption of specific types of fish. These illnesses may originate from the activity of certain bacteria, toxins produced by marine algae, or hazards inherent in the fish.

Commonly occurring illness:

Illness and reporting information for the commonly occurring illnesses are provided in each section. Contact the FDA with any questions or need for clarification of the illness or reporting.

In addition to the illnesses listed above, reporting of other less frequently occurring illnesses from natural toxins may be accomplished by emailing the FDA at Seafood.Illness@fda.hhs.gov.  Refer to Chapter 6 of the “Fish and Fishery Products Hazards and Controls Guidance” for a comprehensive list of natural toxin illnesses. To report illnesses related to miscellaneous natural toxin illnesses, please email FDA at Seafood.Illness@fda.hhs.gov.  

The FDA works with first responders, physicians, and state and local health departments to investigate illnesses and outbreaks, manage them, and learn how to lessen future occurrences.

Ciguatera Fish Poisoning (CFP)

Ciguatera fish poisoning is commonly related to the consumption of subtropical and tropical reef fish which can accumulate naturally occurring ciguatoxins through their diet. The highest incidences of ciguatoxins occur between latitudes 35° north to 35° south, and include areas of the Caribbean Sea, Gulf of Mexico, and Atlantic, Pacific, and Indian Oceans. Refer to Chapter 6 of the “Fish and Fishery Products Hazards and Controls Guidance” for more specific information regarding locations. Many fish species have been associated with CFP including but not limited to: barracuda; grouper; snapper; jacks and trevally; wrasse; mackerel; tang; moray eels; and parrotfish. Ciguatoxins have also been found in lionfish collected in waters surrounding the U.S. Virgin Islands, although no illnesses have been associated with consumption of lionfish to date. Additional species of fish associated with this illness may be found on Table 3-2 Potential Vertebrate Species-Related Hazards in the FDA Fish and Fishery Products Hazards and Controls Guidance.

The onset of symptoms typically occurs within 6 hours after consuming toxic fish and may persist from several days to weeks. In severe cases, some neurological symptoms may persist for months and can recur for years. Fatalities do not usually occur; however, isolated fatalities have been reported. Symptoms of CFP fall into three categories and include:

  • Gastrointestinal:
    • Nausea;
    • Vomiting; and
    • Diarrhea;
  • Neurological:
    • Numbness and tingling of the lips and extremities;
    • Itching of the hands and feet;
    • Joint pain;
    • Muscle pain;
    • Muscle weakness;
    • Reversal and sensitivity to temperature;
    • Dizziness; and
    • Vertigo;
  • Cardiovascular:
    • Irregular heartbeat; and
    • Low blood pressure.

For more information on ciguatera fish poisoning, refer to Chapter 6 in the Fish and Fishery Products Hazards and Controls Guidance and the associated chapter in the FDA Bad Bug Book.

To report CFP related illness(es) please email FDA at Seafood.Illness@fda.hhs.gov.

Puffer Fish Poisoning (PFP)

Puffer fish poisoning (PFP) typically caused by naturally occurring tetrodotoxin is associated with the consumption of puffer fish from waters of the Indo-Pacific Ocean Regions, Gulf of Mexico, Gulf of California, and specific areas on the Atlantic coast of Florida. In addition, an accumulation of saxitoxins in the pufferfish, introduced through their diet, has also been referred to as puffer fish poisoning and should be reported accordingly.

Symptoms usually develop within 3 hours after consumption of contaminated fish and may last from 24 – 48 hours. Death commonly occurs due to muscle paralysis resulting in respiratory failure when ventilatory support is not accessible. Symptoms of PFP include:

  • Numbness of the lips and tongue;
  • Tingling sensation in the face and extremities;
  • Headache;
  • Abdominal pain;
  • Nausea;
  • Diarrhea;
  • Vomiting;
  • Difficulty in walking;
  • Paralysis;
  • Respiratory distress;
  • Difficulty in speech;
  • Shortness of breath;
  • Blue or purplish discoloration of the lips and skin;
  • Lowering of blood pressure;
  • Convulsions;
  • Mental impairment;
  • Irregular heartbeat; and
  • Death in extreme cases.

For more information on Puffer fish poisoning, refer to Chapter 6 in the Fish and Fishery Products Hazards and Controls Guidance and the associated chapter in the FDA Bad Bug Book.

To report PFP related illness(es) please email FDA at Seafood.Illness@fda.hhs.gov. In all PFP cases, determining the source of the suspect fish is critical to assuring that additional unsafe products are not in commerce.

Scombrotoxin Fish Poisoning (SFP)

Scombrotoxin (histamine) formation as a result of time and temperature abuse such as improper storage/refrigeration of certain types of fish can cause consumer illness. SFP is closely linked to the development of histamine in these fish and is primarily associated with the consumption of tuna, mahi-mahi, marlin, and bluefish, among other species. Additional species of fish associated with this illness may be found on Table 3-2 Potential Vertebrate Species-Related Hazards in the Fish and Fishery Products Hazards and Controls Guidance.

Symptoms usually occur within a few minutes to a few hours of consumption and last from 12 hours to a few days. Symptoms of SFP include:

  • Tingling or burning in or around the mouth or throat;
  • Rash or hives on the upper body;
  • Drop in blood pressure;
  • Headache;
  • Dizziness;
  • Itching of the skin;
  • Nausea;
  • Vomiting;
  • Diarrhea;
  • Asthmatic-like constriction of the air passage;
  • Heart palpitations; and
  • Respiratory distress.

For more information on scombrotoxin, refer to Chapter 7 of the Fish and Fishery Products Hazards and Controls Guidance and the associated chapter in the FDA Bad Bug Book.

To report SFP related illness(es) please email FDA at Seafood.Illness@fda.hhs.gov.  

Seafood-associated Rhabdomyolysis (sometimes referred to as Haff disease)

Seafood-associated rhabdomyolysis, also known as Haff disease, has been linked to the consumption of buffalo fish in the United States although other fish species such as burbot, crayfish, eel, pike and salmon have been associated with the disease worldwide. The cause(s) of seafood-associated rhabdomyolysis is unknown.

Seafood-associated rhabdomyolysis results in the breakdown of skeletal muscle (rhabdomyolysis), with a risk of acute kidney failure that develops within 24 hours after consuming certain fish. Initial symptoms include muscle tenderness and weakness, sometimes with tea-colored urine. Blood testing is often used to diagnose seafood-associated rhabdomyolysis/Haff disease with elevated levels of creatine phosphokinase (CPK) being one of the most commonly used indicators.

The FDA is currently collecting meal remnants from patients diagnosed with the disease to confirm the causative species and research the causative agent(s).

For more information on seafood-associated rhabdomyolysis (sometimes referred to as Haff disease), refer to Chapter 6 in the Fish and Fishery Products Hazards and Controls Guidance.

To report seafood-associated rhabdomyolysis (Haff disease) related illness(es), please email FDA at Seafood.Illness@fda.hhs.gov.

Additional Information:

Meal Remnants and Disease Related Information:

The FDA collects meal remnants and epidemiological information, whenever available, to expand our knowledge and information database to better understand these illnesses. This data is critical to improving our understanding of the sources of illnesses, and helps the FDA learn more about the epidemiology and science of these illnesses.

  • Meal remnants:
    • As it relates to natural toxin illness incidents described on this page, the FDA defines a meal remnant as any remaining edible portion of the fish, cooked or uncooked, from the exact fish consumed for the illness incident.
    • Any meal remnants should be immediately frozen and should not be eaten by any other individual(s). The meal remnants should be provided to health care providers or state/local public health authorities. The health care providers or state/local authorities will contact their local FDA District Office to coordinate submission of the remnants for analysis as deemed appropriate.
  • Epidemiological information: The epidemiological information collected will be used as part of a surveillance effort to confirm the sources of illnesses, characterize the responsible toxins, develop testing methodologies (where appropriate), and determine if development and/or refinement of controls for the toxins are warranted. In addition, a better understanding of long-term effects on the patient may be gained. The information gained from this work may assist the FDA in its partnerships with state and local public health departments to reduce future occurrences.

Regulatory Status of Puffer Fish

Due to the severity of puffer fish poisoning, it is important to understand the regulatory status of puffer fish.   

FDA and the Japanese Ministry of Health reached an agreement regarding the importation of a single species of puffer fish, Takifugu rubripes, also known as "Tora Fugu," that are prepared under Japanese safety guidelines and tested prior to importation.  Any puffer fish not imported pursuant to this agreement is subject to FDA’s Import Alert #16-20, which informs FDA field staff that they may detain the fish without physical examination.  Any firms found to be importing puffer fish under false or misleading names to avoid these import restrictions may be placed on the FDA Import Alert #16-04 for species misbranding. Import Alerts can be accessed through Import Alerts by Number (fda.gov).

Puffer fish from domestic sources is sold in the United States and is subject to the seafood HACCP regulation; however, in certain circumstances the FDA will defer to the States for stronger restrictions specifically on harvesting due to toxicity. The southern puffer (Sphoeroides nephelus) occurs in Florida and the Gulf of Mexico and was historically harvested and marketed along with the northern puffers (typically harvested in mid-Atlantic waters) in the sea squab fishery. Between 2002 and 2004, 28 cases of PFP occurred along the east coast of the U.S. and were linked to southern puffers from the Indian River lagoon system along the east (Atlantic) coast of Florida. Southern puffers were previously believed to be non-toxic; however, it is now known that southern puffers - specifically from the Indian River Lagoon system – may also contain saxitoxins derived from an algal source. Furthermore, the toxins in this species, from this location, are contained in the meat, making safe preparation impossible. The state of Florida has banned the commercial and recreational harvesting of all puffer species from the counties of Volusia, Brevard, Indian River, St. Lucie, and Martin, but illnesses still sporadically occur. Commercial harvesting of southern puffers is still allowed on the west coast (Gulf of Mexico side) of Florida. Additional tetrodotoxin-containing species of puffer fish occur in Florida and the Gulf of Mexico as well as on the U.S. west coast, but these fish are not typically consumed.

Investigated Illnesses and Outbreaks

Below is a list of natural toxin illness and outbreak incidents that are no longer active. These incidents have been reported to and managed by the FDA. The information gathered from these incidents will inform the FDA, as well as refine our policy and guidance for management of the program. Data listed below is from September 2019 to present.

Table 1: Closed Illness and Outbreak Incidents

Date Reported FDA Reference Number Illness Type Fish/Fishery Product Case Count Reporting State Additional Comments
11/15/2021 21-11-13 SFP Tuna 2 California Histamine: ≥ 4,200 ppm;
SFP confirmed**
10/27/2021 21-10-12 SFP Tuna 4 Wisconsin Histamine: > 5,700 ppm;
SFP confirmed**
9/22/2021 21-09-10 SFP Yellowfin Tuna 1 Tennessee No meal remnants available
9/22/2021 21-09-09 CFP Grouper 2 Kentucky No meal remnants available
7/22/2021 21-07-08 SFP Tuna 2 New Mexico Histamine: > 3,600 ppm;
SFP confirmed**
7/26/2021 21-07-07 SFP Tuna 3 Massachusetts No meal remnants available
7/8/2021 21-07-06 SFP Tuna 2 Ohio No meal remnants available
7/1/2021 21-06-05 SFP Tuna 3 Indiana No meal remnants available 
6/15/2021 21-06-04 CFP Barracuda 2 New York Analysis pending*
6/9/2021 21-06-03 CFP Unknown Pending Analysis 5 Puerto Rico Analysis pending*
5/24/2021 21-05-02 CFP Salmon 1 Indiana Analysis pending*
3/22/2021 21-03-01 Unknown Lobster 2 California ASP/DA investigated;
no DA detected 
12/17/2020 20-12-10 Haff Buffalo fish 2 Missouri N/A
10/26/2020 20-10-09 CFP Snapper 2 Guam No meal remnants available/
CFP not confirmed 
9/29/2020 20-09-08 CFP Mackerel 5 Puerto Rico Analysis pending*;
In addition to the human illnesses, 4 dogs ill (3 mortalities)  
9/11/2020 20-09-07 SFP Yellowfin Tuna 4 North Dakota No meal remnants available
9/2/2020 20-08-06 CFP Barracuda 2 Illinois Analysis pending* 
8/26/2020 20-08-05 CFP Barracuda 3 Maryland Analysis pending* 
3/2/2020 20-03-01 CFP Warsaw Grouper 1 Florida CTX not detected/
CFP not confirmed 
2/27/2020 20-02-02 Haff Buffalo fish 2 New Jersey N/A
2/27/2020 20-02-01 CFP Hogfish 2 Puerto Rico C-CTX confirmed
1/2/2020 19-12-01 CFP Barramundi 1 Oregon No meal remnants available/
CFP not confirmed 
11/27/2019 19-11-01 CFP Grouper 4 Hawaii P-CTX confirmed
11/8/2019 19-10-06 Haff Buffalo fish 3 Texas N/A
10/29/2019 19-10-01 CFP Hogfish 1 Puerto Rico C-CTX confirmed
10/28/2019 19-10-05 CFP Amberjack 2 Florida C-CTX confirmed
10/25/2019 19-10-04 CFP Barracuda 2 Puerto Rico C-CTX confirmed
10/21/2019 19-10-02 CFP Barracuda 1 Florida C-CTX confirmed
10/18/2019 19-10-03 CFP Barracuda 3 Puerto Rico C-CTX confirmed
9/20/2019 19-09-01 CFP Hogfish 2 Puerto Rico C-CTX confirmed

*Analysis pending: Due to Covid-19 pandemic, our laboratory is currently operating at partial capacity. Sample analysis (CTX testing) is not being conducted at this time. However, all samples will be retained and analyzed in an orderly fashion once the laboratory has reopened at full capacity. Analytical results will be distributed accordingly upon completion.

** In general FDA considers histamine levels greater than or equal to 500 ppm a human health hazard. 


Contact the FDA Division of Seafood Safety at Seafood.Illness@fda.hhs.gov to report a natural toxin in fish other than bivalve molluscan shellfish illness, request a specific illness related questionnaire, or if you have any questions regarding the information on this page.


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