Ciguatera Fish Poisoning Outbreaks Signal Need for Improvements

Ciguatera Fish Poisoning Outbreaks Signal Need for Improvements in Prevention - New York, 2010 -2011 John Hustedt, MPH Nathan Graber, MD, MPH Faina Stavinsky, MS Nancy Clark, MA Jessica Button, MS Scott Martin, MD

Outline • • Background NYC Outbreaks Outbreak Response Challenges in Diagnosis Challenges in Testing for Ciguatoxin Challenges in Treatment Prevention Conclusions

Ciguatera Fish Poisoning • Ciguatera is a naturally occurring fish toxin that affects a wide variety of popularly consumed reef fish. • Ciguatera and related toxins are derived from dinoflagellates, which herbivorous fish consume while foraging through macro-algae • Ciguatera becomes more bioconcentrated as it moves up the food chain

Ciguatera Fish Poisoning • Humans ingest the toxin by consuming large predator reef fish such as barracuda, grouper, and amberjack

Ciguatera Fish Poisoning • Over 50, 000 cases/year worldwide • The toxin is tasteless and heat-stable • Symptoms include diarrhea, abdominal cramps, nausea, headache, vomiting, numbness, and paradoxical dysesthesias • Asymptomatic and symptomatic periods are variable; duration of illness can persist from several months to years

NYC CFP Outbreaks NYC experienced an unusual increase in CFP cases in 2010 -2011. • 29 Cases from 6 outbreaks (2010 -2011) • 24 Cases from 4 outbreaks (2000 -2009) More cases in one year (Aug 2010 -July 2011) than previous 10 years

Initial Outbreaks • August – September 2010 § § § Three outbreaks and one individual case involving thirteen cases All developed CFP like symptoms after consuming barracuda Barracuda purchased at fish markets in three boroughs and one restaurant.

Health Alert Distributed health alert to physicians in November 2010. § Receiving physician reporting an additional outbreak with eleven cases § All developed CFP like symptoms after consuming grouper purchased from a supermarket in queens

Additional Outbreaks • July 2011 § § § Two outbreaks involving five cases All developed CFP like symptoms after consuming grouper Grouper consumed at two restaurants in Manhattan

Case Interviews • 24 cases were interviewed • Five cases were not aware what type of fish they consumed Table 1: CFP Cases Reporting Various Symptoms in NYC, 2010 -11 Symptom # (%) Diarrhea 20 69% Difficulty walking 19 66% Abdominal cramps 21 72% Itching 16 55% Nausea 15 52% Headache 13 45% Muscle ache 13 45% Vomiting 13 45% Numbness/tingling 11 38% Dizziness 9 31% Paradoxical dysesthesias 6 21%

NYC Outbreak Response § Four samples of fish consumed by cases were collected and tested positive for ciguatoxins § New York State Department of Agriculture and Markets (NYS DAM) and FDA traced all fish back to two distributors in Florida

NYC Outbreak Response Analysis of CFP calls to American Association of Poison Control Centers from 2000 -2010 showed: § Increase of 55% in NYC § Decrease in 44% in Florida § No change nationwide

Challenges in Diagnosis • In South Florida, where CFP is considered endemic, one study found that only 68% of physicians presented with a typical case of CFP diagnosed it correctly* • In addition, it is estimated that only 2 -10% of CFP cases are reported to health authorities** • Raising awareness and increasing familiarity among health care providers is critical to increase reporting and investigation • Releasing a health alert in NYC helped find an additional outbreak

Challenges in Testing for Ciguatoxin • No standardized, quick-turnaround test to identify CT in fish § membrane immunobead assay using a color change indicator – § Studies show significant variation in sensitivity and specificity In vitro assay and liquid chromatographymass spectrometry (LC-MS)

Challenges in Treatment • Treatment options for CFP are limited and as of yet still unproven § IV mannitol – – § § § Numerous case reports Recent double-blind, randomized control trial Amitriptyline Fluoxetine GABApentin

Prevention • Increase surveillance in areas where reef fish are consumed • Increase provider awareness of CFP symptoms • Trace back investigations to identify high-risk fishing areas • Update HACCPs and consider banning fishing for certain species in high-risk areas to reduce exposure • Develop a rapid test for CT to identify high-risk fish and reefs.

Conclusions • Identified unusual increase in CFP cases • Used traditional public health investigation to track back source • Importance of provider awareness and reporting • Need to overcome challenges in identifying CT in fish and preventing toxic fish coming to market

References * Mc. Kee D, Fleming LE, Tamer R, Weisman R, Blythe DG. Physician diagnosis and reporting of ciguatera fish poisoning in an endemic area. Harmful Algal Blooms 2001; 451 -53. ** Friedman MA, Fleming LE, Fernandez M, et al. Ciguatera Fish Poisoning: Treatment, Prevention and Management. Mar Drugs 2008; 6: 456 -79. The findings and conclusions in this report are those of the author(s) and do not necessarily represent the official position of the Centers for Disease Control and Prevention or the New York City Department of Health and Mental Hygiene.