PRACTICE | CASES CME

Ciguatera fish after Caribbean travel

Courtney A. Thompson MD MSc, Farah Jazuli MSc, Linda R. Taggart MD MPH, Andrea K. Boggild MSc MD n Cite as: CMAJ 2017 January 9;189:E19-21. doi: 10.1503/cmaj.151207

Case 1 KEY POINTS A previously healthy 39-year-old Canadian-born man travelled to • Ciguatera is a marine that may occur following ingestion Havana, , for one week on business. He stayed in a local home of large reef fish such as snapper, barracuda, and eel. and ate foods prepared by the family. The night before his depar- • Sensation of hot–cold temperature reversal to liquids and solid ture home, he ate two portions of a large fish identified by the host objects is the pathognomonic sign of ciguatera, but it is present as a (Figure 1). Two days after his return, he noted in only 50% of those affected. prominent symptoms of temperature inversion (i.e., reversal of hot • are not destroyed by or freezing; therefore, and cold sensations) in his upper and lower extremities: his hands improper food preparation, handling and storage are not implicated in the pathogenesis of ciguatera. felt subjectively hot and “burning” when he washed them in cold Diagnosis is clinical and rests on compatible epidemiology and water, he was unable to discern hot from cold face cloths, and he • the presence of characteristic , such as experienced “burning hot” feet while walking barefoot on cold, sensation of hot–cold temperature reversal. tiled floors. The symptoms of temperature reversal did not occur • Management is supportive. when he ate or drank and were not prominent when he showered. He also described a tingling sensation around his mouth and nose, as well as painful joints, particularly his knees and elbows. He had and were characterized by worsening joint pain, tingling and par- no gastro­intestinal symptoms, rash or palpitations. esthesia of the face and extremities, and insomnia. By six weeks af- On examination, the patient was well and alert and oriented to ter onset, the symptoms had resolved entirely, and the patient re- person, time and place. He was afebrile and had a regular pulse. turned to his normal diet without restrictions. He remained well at There was no facial asymmetry, and sensation to light touch was six weeks, and three and six months after symptom resolution. normal throughout. He had full power in his upper and lower extremities, and his gait was normal. There was no rash, and his Cases 2 and 3 joints were not red or swollen. A clinical diagnosis of ciguatera was made, and the patient was advised to avoid consuming fish, nuts, A husband and his wife, both Guyanese-born and 68 years old, trav- caffeine and for at least six months. elled to the Dominican Republic for one week to visit family and His symptoms continued intermittently, with noted exacerba- friends. While there, they purchased and ate local fish that was tions following heavy exercise and alcohol consumption. Exacer- cooked and sold on a rural beach close to Santo Domingo. About bations occurred on three occasions over the subsequent month four hours later, they and their friends began to feel unwell with , and . About two days later, the husband and wife experienced severe generalized pruritus. Two days after that, both began to have unusual sensations when drinking cold liq- uids: the husband had an odd sensation on his tongue, and the wife had symptoms of temperature reversal. She reported that her hands felt burning hot while rinsing them in cold water, and her husband experienced perioral numbness, weakness of his hands and a cold sensation of his left foot. Both were evaluated in Canada in local emergency departments before referral to a tropical disease unit at an academic tertiary care centre. The husband underwent a full stroke work-up for transient numbness of his left arm and leg, the results of which were negative. Hydroxyzine was prescribed to both patients for the pruritus, which led to mild improvement. In follow-up in the tropical disease unit, about one month after symptom onset, both patients appeared well, were afebrile and Figure 1: Dog snapper eaten by a 39-year-old man while in Cuba (case 1). had a regular pulse. Findings on cranial nerve examination were

© 2017 Joule Inc. or its licensors CMAJ | JANUARY 9, 2017 | VOLUME 189 | ISSUE 1 E19 PRACTICE E20 Woods HoleOceanographic Institution,WoodsHole, Mass. Figure 2: alytic shellfishpoisoninginthesameperiod. ofscombroidfishpoisoning andneurotoxicorpar- contrast to7 cases the globalGeoSentinelsurveillancenetworkoverafive-yearperiod,in ing andhasthelowestmortality.Atotalof51caseswerereportedto reportable illness. Ciguatera is the most prevalent type of fish - adians returningfromhigh-riskregionsisunclear,becauseitnota tors to,islandssurroundedbycoralreefs.TheincidenceamongCan Ciguatera isafood-borneillnessthatoccursininhabitantsof,andvisi- Discussion resolved, andbothbegantoreintroducefishtheirdiet. mild. Byfourmonths,theirsymptomshadalmostcompletely the wife’s temperature reversal and husband’s perioral tingling were after theonsetofsymptoms,pruritushadimprovedinboth,and triggers, andneitherhadexacerbationofsymptoms.Bytwomonths wise bothpatientswereabletoreducetheirconsumptionofdietary alcohol foratleastsixmonths. patients wereadvisedtoavoidconsumingfish,nuts,caffeineand swollen joints. A clinical diagnosis of ciguatera was made, and the to lighttouchsensationoftheleftfoot.Neitherhadarash,orred extremities andhadanormalgait.Thehusbandmildreduction normal. Thepatientshadfullpowerintheirupperandlower found on coral reefs. ing. TheyoriginatefromplanktonspeciesinthegenusGambierdiscus havenoodorandarenotdestroyedbycookingorfreez- Pathogenesis large numbersofcasesgoundiagnosedorunreported. eel. gestion oflargereeffishsuchasgrouper,snapper,barracudaand Adherence tocaffeineavoidanceprovedchallenging,butother- 3

Unlike other food-borne intoxications (e.g., botulism), improper Unlikeotherfood-borneintoxications(e.g.,botulism),improper Global Office distribution for Harmful of Algalciguatera Blooms, fish poisoning (CFP). Reproduced with permission from the US National 2 The toxins are transmitted to humans via in CMAJ 1 However, it is likely that However,itislikelythat | JANUARY 9, 2017 - ­

| VOLUME 189 the diagnosis. but itoccursinonly50%ofcases;thus,itsabsencedoesnotpreclude Temperature reversalisthepatho Clinical manifestations ( Caribbean, theyarefoundinthePacificandIndianOceansaswell of theaffectedfish. or banquetsettingsbecausemanypeoplemayingestlargeportions pathogenesis ofciguatera.Outbreakscommonlyoccurinrestaurant handling, storage and preparation offish are not implicated inthe present within minutes to a few hours after ingestion. Ciguatera has present withinminutestoafewhoursafteringestion.Ciguaterahas ing, scombroidfishpoisoningandpuffertypically ciguatera. Paralyticshellfishpoisoning,neurotoxicpoison- clinical features, butthey usually have amore rapid onset than from differentfishandseafoodspeciesmaypresentwithsimilar history of the type of fish eaten. from other marine toxins absence ofthepathognomonicfindingtemperaturereversaland The diagnosisofciguaterafishpoisoningcanbechallenginginthe more prominentinciguaterafromthePacificandIndianOceans. Caribbean, whereasneurologicandcardiovascularsymptomsare trointestinal symptomspredominatefromciguateraacquiredinthe duration ofillnessmayvarybygeographicregionacquisition.Gas- sion, whichoccursinaminorityofreportedcases.Symptomsand sometimes necessarybecauseofseverebradycardiawithhypoten- tional totheamountofingestedtoxin(Box1).Hospitaladmissionis and cardiacmanifestations,withsymptomseveritydirectlypropor- toms ofciguateraincludecutaneous,gastroenterologic,neurologic objects feelhotorinducedysesthesiaandviceversa.Othersymp- Figure 2). Although ciguatoxinsarepredominatelyconcentratedinthe | 4 ISSUE 1 Temperaturereversalisthesensationthatcold

gnomonic symptomofciguatera, ­ 5,6

PRACTICE ​ ​ - 56: E21 2005;4: 2010; Med Trop Toxicon Lancet Neurol 91. - ​ 1689 : Mass ciguatera poisoning after : treat- Ciguatera fish poisoning in the Ciguatera fish poisoning in the Global distribution of ciguatera Global distribution of ciguatera Although previous studies studies previous Although 2006;9 3 et al. et al. et al. et al. GeoSentinel surveillance of illness in GeoSentinel surveillance of illness in , MA, Ciguatera fish poisoning in the Caribbean Ciguatera fish poisoning in the Caribbean et al. - associated with wors have all been Ciguatera fish poisoning: a double-blind ran- 8,9 RJ. , MD, China Trop Med Neurotoxic marine poisoning.

MW, Faust Clinical analysis of a collective poisoning acci- Ciguatera: a public health perspective. TD, Johnstone R MC. Libman 10 JP, Lewis SM. , , et al. , and alcohol ISSUE 1 ISSUE 8,9 | , Lin Z MA, Fleming LE, Fernandez M, Torresi J MP, Brewer , Vernoux L, Hayek-Lanthois M, Joossen F, GK, Kiernan , ,

RW, Vandersea H, Taurarii M, Cundy T.

I RW, Plakas

K , Wei H 36. -28. - Z 8 Isbister 219 Liu De Haro Pacific Islands (1998 to 2008). PLoS Negl Trop Dis 2011;5:e1416. 2001;168:99-141. islands and western Atlantic. Rev Environ Contam Toxicol domized trial of therapy. 2002;58:873-80. Skinner dent in a banquet [Chinese]. eating barracuda in Mexico: prognostic and therapeutic implications. (Mars) 1997;57:55-8. Schnorf ment, prevention and management. Mar Drugs 2008;6:456-79. Leder Pottier returned travelers, 2007–2011. Ann Intern Med 2013;158:456-68. Litaker 123 Friedman Dickey 2010;56:711-30. causing in the genus . Toxicon Patient-level prevention includes education on the avoidancePatient-level prevention

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10. of consuming large tropical reef fish. Beyond complete avoidanceof consuming large tropical species, risk can be reduced by eating of implicated marine (< 2 fish smaller to tend that fish of parts avoiding by and kg) or such as the head, , skin and visceral ­accumulate the , interventions, such as greater globalgans. Large-scale preventive - trade and diligence surrounding environ regulation of marine coordination andmental monitoring, require broad international engagement. have suggested mannitol infusion as a treatment for neurologic neurologic for treatment a as infusion mannitol suggested have dif- a randomized controlled trial found no symptoms of ciguatera, patients given mannitol and controlsference in outcome between given normal saline. ening of symptoms, as has exercise. ening of symptoms, References Contributors: Andrea Boggild and Courtney Thompson conceived and drafted the manuscript. All of the authors contributed to the literature review, revised the manuscript critically for important intellectual con- tent, approved the final version to be published and agreed to act as guarantors of the work. Acknowledgement: The authors gratefully acknowledge Rachel Lau and Jennifer Ma for their assistance with translating reference 8. Correspondence to: Andrea Boggild, [email protected] Conclusion marine poisonings, is Ciguatera fish poisoning, among other to potentially unnec- underrecognized in Canada, which can lead patient. Early recogni- essary investigations and morbidity in the in result can ciguatera of features clinical identifying the of tion use of resources. improved patient care and more efficient Management on rests ciguatera with patient ambulatory the of Management large rigor- triggers. Although of potential exacerbating avoidance caffeine, pea- of consumption of are lacking, reports ous studies nuts,

VOLUME 189 VOLUME | 24 h) Diag- 7 1–3 d JANUARY 9, 2017 JANUARY | Weeks to months Weeks to Time to resolution 3 1–4 d (typically ≤ 1–4 d (typically CMAJ London School of Hygiene & Tropical Medicine (Thompson), ​/lookup/suppl/doi:10.1503/cmaj.151207/-/DC1). If present, the sensation of temperature reversal distinguishesIf present, the sensation of temperature reversal - Depart Toronto; of University (Jazuli), Medicine of Faculty UK; London, ment of Medicine (Taggart, Boggild), University of Toronto; Division of Infectious Diseases (Taggart), St. Michael’s Hospital, Toronto, Ont.; Tropi- cal Disease Unit, Division of Infectious Diseases, Department of Medicine Health Network; Public(Boggild), Toronto General Hospital, University Health Ontario Laboratories (Boggild), Toronto, Ont. Competing interests: None declared. This article has been peer reviewed. The authors have obtained patient consent. Affiliations: *The sensation that cold objects feel hot or result in dysesthesia (abnormal sensation) (abnormal sensation) in dysesthesia or result hot feel objects cold that *The sensation it is considered in all patients, present is not Although this phenomenon versa. or vice of ciguatera. pathognomonic (numbness and (numbness Paresthesia Neurologic: or near and around tingling) in the extremities reversal of temperature the mouth, sensation , inversion),* (hot–cold diarrhea, vomiting, Nausea, Gastrointestinal: abdominal cramping block, heart , Cardiovascular: pruritus, generalized Other: Myalgia, dysuria , , arthralgia, Box 1: Clinical characteristics of ciguatera of characteristics 1: Clinical Box Symptoms

Diagnosis investigations ofThe diagnosis of ciguatera is clinical. Sophisticated and magnetic reso- paresthesia, such as nerve conduction studies and not helpful. nance imaging of the brain, are unnecessary ciguatera from other similar conditions. Symptoms are otherwiseciguatera from other similar conditions. Symptoms diagnoses. other with overlap considerable have and nonspecific as organophosphateIllnesses caused by nonmarine toxins, such and neurologic fea- poisoning or botulism, share gastrointestinal withtures with ciguatera. Early presentations of difficult to distin- predominant sensory symptoms may be initially symptoms. Inguish from ciguatera before the onset of additional a misdiagnosis ofpatients whose symptoms persist for months, historyexposure thorough A occur. may syndrome fatigue chronic is helpful in narrowing the differential diagnosis. a more delayed onset, from several to 12 hours on average, and in 1, available atsome cases 24–48 hours after ingestion (Appendix www.cmaj.ca nosis relies on the identification of symptoms typical of ciguateranosis relies on the identification of symptoms Laboratory history. travel or exposure appropriate with combined diagnosis is typically unavailable, and clinical suspicion is sufficient. Definitive diagnosis is usually unnecessary, because treatment op- tions for marine intoxications are largely supportive. Laboratory de- tection of the toxin in remaining fish or may be undertaken in outbreak settings when such samples are available for testing.