Seafood safety risks include bacterial infections associated with marine exposure and illnesses caused by naturally occurring marine toxins. In 2024, CDC surveillance recorded 3,755 Vibrio infections in the United States, including 3,743 vibriosis cases. A separate CDC review of finalized foodborne outbreak reports found 402 marine-toxin outbreaks during 2011–2023, causing 1,280 illnesses, 96 hospitalizations, and one death.
Contents
- U.S. Vibrio infections and outcomes
- Where reported vibriosis cases occurred
- Seafood and marine exposure patterns
- The national marine-toxin burden
- Foods, sourcing, and preparation settings
- Ciguatoxin and fish species
- Shellfish-toxin outbreaks
U.S. Vibrio infections and outcomes
The CDC’s Cholera and Other Vibrio Illness Surveillance: Annual Summary, 2024 reports cases submitted to the Cholera and Other Vibrio Illness Surveillance system (COVIS). Of the 3,743 vibriosis cases, 1,459 were culture-confirmed and 2,239 were probable cases detected by culture-independent diagnostic testing. Another 45 were epidemiologically linked probable cases. The summary also recorded 12 cholera cases.
The clinical outcomes show why seafood safety remains important even though the surveillance totals are reported cases rather than population-wide estimates. Hospitalization status was known for 3,278 vibriosis cases. Of those, 1,050 patients were hospitalized, equal to 32%. Outcome status was known for 3,450 cases, including 73 reported deaths, or 2%.
The reported age profile was broad. The median age was 56 years, with patients ranging from under 1 year to 98 years. Among 3,660 cases with known sex, 1,911 patients were male, or 52%.
The main 2024 outcome figures are:
| Measure | CDC-reported figure | Scope |
|---|---|---|
| Vibrio infections | 3,755 | United States, 2024 |
| Vibriosis cases | 3,743 | United States, 2024 |
| Culture-confirmed vibriosis | 1,459 | Reported 2024 cases |
| Hospitalized | 1,050 of 3,278 | Cases with known status |
| Deaths | 73 of 3,450 | Cases with known status |
These figures should not be read as an estimate of every infection in the country. They describe cases reported to COVIS, and the CDC notes that California residents were not reported to COVIS for 2024.
Where reported vibriosis cases occurred
Forty-nine jurisdictions reported 3,698 vibriosis cases for the geographic breakdown in 2024. Atlantic Coast states accounted for 1,476 cases, or 40% of that total. Non-coastal jurisdictions reported 1,027 cases, or 28%, while Gulf Coast states reported 996, or 27%.
Pacific Coast states accounted for 199 cases, or 5% of the geographic-breakdown total. California cases were not reported to COVIS, so the Pacific Coast figure does not represent all cases among residents of that state.
The geographic distribution is not limited to shorelines. The non-coastal total of 1,027 reported cases illustrates why food handling, distribution, travel, and exposure history matter alongside where a person lives. These are surveillance categories, not a measurement of individual risk for every coastal or inland community.
Species reporting adds another layer. CDC recorded 499 Vibrio parahaemolyticus cases in 44 jurisdictions and 222 Vibrio vulnificus cases in 29 jurisdictions. Among 1,290 culture-confirmed cases, V. parahaemolyticus accounted for 472, or 36%.
Seafood and marine exposure patterns
Among 3,289 domestically acquired vibriosis cases with known transmission classification, 2,548, or 77%, were foodborne or likely foodborne. A further 559, or 17%, were non-foodborne or likely non-foodborne, and 182, or 6%, had unknown transmission. The denominators matter: these percentages describe cases with known classification, not all reported Vibrio infections.
Seafood histories were available for 1,385 domestically acquired vibriosis patients. Oysters were reported by 603 patients, or 44%; shrimp by 596, or 43%; and fish by 538, or 39%. These categories can overlap because a patient could report more than one seafood item.
Among 745 patients who reported eating one seafood item, oysters were the single item for 287 patients, or 36%. Of those 287 single-item oyster reports, 231, or 87%, involved oysters eaten raw. This is an exposure description, not a calculation of the risk of eating any particular oyster or serving.
Marine contact also appeared in the surveillance data. Among 746 domestically acquired vibriosis patients reporting marine or estuarine exposure, 622, or 83%, reported skin exposure to a body of water. Contact with drippings from raw or live seafood was reported by 239 patients, or 32%.
Together, the figures cover several routes: foodborne or likely foodborne transmission, raw oyster consumption among single-item seafood reports, direct water contact, and contact with seafood drippings. They do not establish that every reported exposure caused an illness.
The national marine-toxin burden
The CDC’s Foodborne Disease Outbreaks Associated with Marine Toxins — Foodborne Disease Outbreak Surveillance System, United States, 2011–2023 reviewed finalized foodborne outbreaks voluntarily reported to FDOSS. It identified 402 marine-toxin outbreaks during 2011–2023. Those outbreaks caused 1,280 illnesses, 96 hospitalizations, and one death.
The median number of reported outbreaks per year was 30, with an annual range of 11 to 52. The median number of illnesses per outbreak was 2, with a range of 2 to 50. The national reported rate was 1.2 outbreaks per 1 million population during the period.
Reported rates varied geographically. Hawaii had the highest rate at 25.3 outbreaks per 1 million population. Puerto Rico’s rate was 16.5 per 1 million, and Florida’s was 6.3 per 1 million.
These marine-toxin figures are not a complete count of all illness. The CDC describes them as finalized outbreaks voluntarily reported to FDOSS and notes that they likely underestimate total illness. The annual totals also cover 2011–2023, rather than the 2024 Vibrio surveillance year.
Foods, sourcing, and preparation settings
Scombroid toxin and ciguatoxin together accounted for 381 of the 402 marine-toxin outbreaks during 2011–2023, or 95%. A single food source was identified in 396 outbreaks, or 99% of the total. Fish were implicated in 379 of those 396 single-food-source outbreaks, or 96%; shellfish were implicated in 12, or 3%.
Among 313 reports with known importation status, 219, or 70%, identified food that was not imported. Harvest information was available for 157 reports, and 42, or 27%, indicated recreational harvest.
Preparation location was reported for 377 investigations. Private homes were linked to 193, or 51%, and restaurants to 147, or 39%. Sit-down dining restaurants accounted for 130 of the 147 restaurant-associated outbreaks, equal to 34% of all 377 investigations.
The two leading toxin categories had different profiles:
| Toxin | Outbreaks | Illnesses | Hospitalizations |
|---|---|---|---|
| Scombroid toxin | 192 | 597 | 6 |
| Ciguatoxin | 189 | 619 | 67 |
Scombroid toxin caused 192 outbreaks, 597 illnesses, and 6 hospitalizations. Ciguatoxin caused 189 outbreaks, 619 illnesses, and 67 hospitalizations. The counts describe reported outbreaks during 2011–2023 and should not be treated as forecasts.
Ciguatoxin and fish species
Among 187 ciguatoxin outbreaks with an identified food source, barracuda was implicated in 58, or 31%. Grouper appeared in 25, or 13%, and amberjack in 22, or 12%.
Importation and harvest details point toward locally obtained fish in the reported ciguatoxin records. Among 164 ciguatoxin reports with importation status, 142, or 87%, implicated domestically caught fish. Among 60 reports with harvest information, 36, or 60%, indicated recreational harvest.
These percentages use the subsets for which the CDC report had the relevant information. They do not mean that every barracuda, grouper, amberjack, or recreationally caught fish contains ciguatoxin.
Shellfish-toxin outbreaks
The report recorded three named shellfish-toxin categories. Paralytic shellfish poisoning caused 6 outbreaks, 23 illnesses, and 4 hospitalizations during 2011–2023. Neurotoxic shellfish poisoning caused 4 outbreaks, 10 illnesses, and 3 hospitalizations. Amnesic shellfish poisoning caused 1 outbreak, 2 illnesses, and 2 hospitalizations.
Across 13 shellfish-associated toxin outbreaks, Florida reported 5, or 38%, and Alaska reported 4, or 31%. Mussels were implicated in 4 outbreaks, or 31%; sea snails in 4, or 31%; and clams in 3, or 23%.
Harvest information was available for 7 shellfish-associated toxin reports. Six, or 86%, indicated recreational harvest. As with the ciguatoxin figures, this is a characteristic of the reported subset, not a general probability for recreationally harvested shellfish.
For practical seafood decisions, the statistics support keeping several distinctions clear: reported surveillance cases versus population-wide estimates; 2024 Vibrio data versus 2011–2023 marine-toxin data; foodborne exposure versus water or handling exposure; and toxin outbreaks tied to identified foods versus all seafood consumption. Those distinctions preserve the scope of what the CDC measurements show.