Got your attention? Food poisoning causes more problems that you thought. The CDC actually reported this today in MMWR:
Ciguatera fish poisoning (CFP) is a distinctive type of foodborne disease that results from eating predatory ocean fish contaminated with ciguatoxins. As many as 50,000 cases are reported worldwide annually, and the condition is endemic in tropical and subtropical regions of the Pacific basin, Indian Ocean, and Caribbean. In the United States, 5–70 cases per 10,000 persons are estimated to occur yearly in ciguatera-endemic states and territories (1). CFP can cause gastrointestinal symptoms (nausea, vomiting, abdominal cramps, or diarrhea) within a few hours of eating contaminated fish. Neurologic symptoms, with or without gastrointestinal disturbance, can include fatigue, muscle pain, itching, tingling, and (most characteristically) reversal of hot and cold sensation. This report describes a cluster of nine cases of CFP that occurred in North Carolina in June 2007. Among the nine patients, six experienced reversal of hot and cold sensations, five had neurologic symptoms only, and overall symptoms persisted for more than 6 months in three patients.
Among seven patients who were sexually active, six patients also complained of painful intercourse. This report highlights the potential risks of eating contaminated ocean fish. Local and state health departments can train emergency and urgent care physicians in the recognition of CFP and make them aware that symptoms can persist for months to years.
On June 28, 2007, a woman and her husband (the index couple), both aged 31 years, were treated at a hospital emergency department for illness that developed within 24 hours after eating amberjack fish purchased from a local fish market and cooked at their home. Diagnoses of CFP were based on symptoms of mild diarrhea 4–12 hours after eating fish, followed by reversal of hot and cold sensation, abnormal skin sensations, and other neurologic symptoms within 24 hours. Both patients improved after treatment with intravenous mannitol, a long-standing treatment for CFP neurologic symptoms. Upon notification, investigators from the Food and Drug Protection Division of the North Carolina Department of Agriculture and Consumer Services contacted the fish market that sold the amberjack filets and discovered that seven of eight persons at a local dinner party also had become ill after eating amberjack from the same shipment. The one person who did not become ill was a young child who did not eat any fish.
For the subsequent investigation, a case was defined as illness with gastrointestinal or neurologic symptoms within 72 hours of eating amberjack purchased at the fish market in June 2007. The nine patients whose illnesses met the case definition included three males and six females, aged 31–44 years (median: 37 years). Patients became ill 4–48 hours (median: 12 hours) after eating the fish. Abnormal skin sensations, joint pains, or weakness, shakiness, or fatigue affected seven patients (Table). For three persons, symptoms reappeared or worsened after alcohol consumption. Six of seven sexually active patients (two males and four females) also reported painful intercourse as a symptom. Both males described painful ejaculation with intercourse. One male stated that ejaculation was painful during the course of 1 week; the duration of the second male’s genitourinary symptoms was not reported. All four females described having a burning sensation during intercourse and 15 minutes to 3 hours after intercourse. Two females reported that burning sensations associated with intercourse continued for 1 month. Severity of illness could not be related to the amount of amberjack consumed nor to the incubation period.
Symptoms (i.e., abnormal skin sensations, itching, fatigue, or altered heat-cold sensation) lasted at least 1 month in all nine patients, but cleared within 6 months in six of the patients (Table). Abnormal skin sensations persisted for 6–12 months in one of the nine patients; 1 year after onset of their CFP illnesses, two of the nine patients were still experiencing occasional symptoms of abnormal skin sensations, and one of those two was easily fatigued.
Samples of cooked amberjack were sent to the Food and Drug Administration (FDA) Gulf Coast Seafood Laboratory in Dauphin Island, Alabama, for ciguatoxin analysis. Acetone extracts of fish tissue were analyzed for ciguatera-related toxins using the sodium channel-specific mouse neuroblastoma assay with Caribbean ciguatoxin-1 (C-CTX-1) as a standard (2). A level of 0.6 ng C-CTX-1 equivalents per gram (0.6 ppb) of fish flesh was found in both fish samples, and C-CTX-1 was confirmed by liquid chromatography/mass spectrometry.
The first female patient had become symptomatic within 24 hours of eating the fish. She proactively collected, stored frozen, and submitted four breast milk samples for testing at the FDA laboratory because she was breastfeeding her infant and, upon researching CFP on the Internet and speaking with a Florida physician who had treated cases of CFP, had learned that breast milk might be a transmission vehicle. Against medical advice, she continued to breastfeed, but her infant, aged 8 months, exhibited no observable adverse effects. She collected one of the breast milk samples previous to eating the amberjack and the other samples at 1, 2, and 5 days after eating the fish. No activity of C-CTX-1 was reported by the FDA laboratory in any of the breast milk samples.
Traceback of the fish responsible for this cluster of CFP cases revealed that the fish was shipped to the local fish market via a seafood distributor in Atlanta, Georgia. The amberjack had been caught off the Islamorada Hump in the Florida Keys.