EPI UPDATE

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For information on diseases and conditions of public health importance go to MyFlorida.com, click on Health and Human Services, then Consumers--Diseases and Conditions.

Janet Wamnes, M. S., Bureau of Environmental Epidemiology

Roberta M. Hammond, Ph.D., Bureau of Environmental Epidemiology

Background

On October 28, 2001, the Palm Beach County Health Department was informed by a physician at a local hospital of a ciguatera intoxication occurring on October 27. Three persons from three separate parties consumed black grouper at a local restaurant on October 27. On October 30 and 31, the Martin County Health Department was informed by a local physician of ciguatera intoxication occurring on October 27 and 28. Three more persons had consumed black grouper at a local restaurant on October 27 and 28 in Martin County. On November 1, the Martin County Health Department was notified of two more persons experiencing symptoms consistent with ciguatera intoxication after consuming black grouper at yet another local restaurant on October 27 in Martin County. Also on November 1, the Palm Beach County Health Department was notified of three additional persons experiencing symptoms consistent with ciguatera intoxication after consuming black grouper at the same restaurant as the original three cases on October 27.

Table 1: Line Summary of Cases

The first three persons in Palm Beach County developed diarrhea, vomiting, and abdominal cramps within 6 hours after consuming the fish. Later they developed tingling and numbness in the gums, itching, weakness in their legs, reversal of hot-cold sensations, difficulty in breathing, body aches, and joint and muscle pain, with recurring symptoms of itching. The first 3 persons from Martin County developed nausea, diarrhea, and abdominal pain. One of these persons also experienced vomiting within 5 hours after consuming the fish. Later, the 3 Martin County persons developed tingling and numbness in the gums, pin-prickling in hands and feet, body aches, reversal of hot-cold sensations, and itching, with recurring symptoms of itching and weakness. The second group of persons that ate grouper at a different local restaurant in Martin County on October 27 developed diarrhea and abdominal cramps within 4 hours after consuming the fish. Later they developed tingling and numbness in the lips, nose, and tongue, body aches, reversal of hot-cold sensations, and itching. The last group of persons that ate grouper at the Palm Beach County restaurant developed diarrhea, nausea, and abdominal pain within 6 hours after consuming the fish. Later they developed tingling and numbness in the lips, nose, and tongue, body aches, reversal of hot-cold sensations, and itching, with recurring symptoms of itching and weakness.

The Bureau of Environmental Epidemiology, the Palm Beach County Health Department, the Martin County Health Department, the Florida Department of Agriculture and Consumer Services, and the Department of Business and Professional Regulation were immediately notified after each complaint. Investigations by the respective County Health Departments, the Bureau of Environmental Epidemiology and the Departments of Business and Professional Regulation and Agriculture and Consumer Services were conducted at each implicated restaurant, fish market, and fish supplier. All of the restaurants where the outbreaks occurred had obtained the black grouper from the same distributor located in Broward County. Leftover black grouper was obtained from the initial investigation in Palm Beach County to be tested for ciguatoxin by the Food and Drug Administration.

Summary

A total of 11 cases of ciguatera intoxication from the consumption of black grouper bought at restaurants in Martin and Palm Beach Counties from different fish markets but from the same supplier and same source lot in Broward County were identified. Six of the cases consumed the fish at the same restaurant in Palm Beach County on October 27, 3 in one party, 3 in another party. Three of the cases consumed the fish at the same restaurant in Martin County on October 27 and 28, 2 in one party, and 1 in another party. Two of the cases consumed the fish at a different restaurant in Martin County on October 27.

The fish market in Palm Beach County had purchased over 200 pounds of black grouper and the fish market in Martin County had obtained 1600 pounds of the fish from a licensed supplier in Broward County on October 25. The Florida Department of Agriculture and Consumer Services obtained invoices from the supplier that indicated the black grouper was obtained from a vendor in Freeport, Bahamas. The two fish markets that supplied the fish to the three restaurants in Martin and Palm Beach County as well as the fish supplier in Broward County were issued a stop-sale for the implicated lot of black grouper. Staff of the Martin and Indian River County Health Departments and the Bureau of Environmental Epidemiology called 25 restaurants in Martin, St. Lucie, Indian River, Okeechobee and Palm Beach Counties who had also purchased the fish from the Martin County fish market. The restaurants were asked to discard the fish because of the outbreak. The black grouper obtained for testing was positive for ciguatoxin. Because one of the Palm Beach County cases was a resident of the State of Indiana, an EpiX alert was posted as well as an alert on the Foodborne Outbreak listserve. No other out-of-state cases were identified. No further clusters were identified in this outbreak.

Ciguatera poisoning is a notifiable (reportable) disease in Florida (s. 64D-3.002(1)j, Florida Administrative Code) and should be reported to the local county health department by the attending physician. It is a form of human poisoning caused by the consumption of subtropical and tropical marine finfish which have accumulated naturally occurring toxins through their diet. Marine finfish most commonly implicated in ciguatera fish poisoning include the groupers, barracudas, snappers, jacks, mackerel, and triggerfish. Many other species of warm-water fish harbor ciguatera toxins. The occurrence of toxic fish is sporadic, and not all fish of a given species or from a given locality will be toxic. The ciguatoxins can be recovered from toxic fish through tedious extraction and purification procedures. The mouse bioassay is a generally accepted method of establishing toxicity of suspect fish.

Clinical testing procedures are not presently available for the laboratory diagnosis of ciguatera in humans. Diagnosis is based on symptom history and recent dietary history. Initial signs of poisoning occur within 6 hours after consumption of toxic fish and include perioral numbness and tingling (paresthesia), which may spread to the extremities, nausea, vomiting, and diarrhea. Neurological symptoms include intensified paresthesia, arthralgia, myalgia, headache, temperature sensory reversal and acute sensitivity to temperature extremes, vertigo, and muscular weakness to the point of prostration. Cardiovascular signs include arrhythmia, bradycardia or tachycardia, and reduced blood pressure. Ciguatera poisoning is usually self-limiting, and signs of poisoning often subside within several days from onset. However, in severe cases the neurological symptoms are known to persist from weeks to months.

Carina Blackmore, MS, Vet. Med., PhD.

Samuel Crane, MPH

National report: During week 43 (October 21-27, 2001), three specimens tested by the World Health Organization (WHO) and National Respiratory and Enteric Virus Surveillance System (NREVSS) collaborating laboratories across the United States were positive for influenza. Since September 30^th, a total of 3,148 specimens for influenza viruses have been tested and 20 (1%) were positive. Of the 20 isolates identified, 19 were influenza A viruses and 1 was an influenza B virus. Nine of the influenza A viruses were subtyped, all were influenza A (H3N2). Influenza A isolates have been identified in Alaska, Arizona, Louisiana, New York, and Texas. The influenza B isolate was identified in Texas.  The proportion of patient visits to sentinel physicians for influenza-like illness (ILI) overall was 1.3%, which is less than the national baseline of 1.9%. The proportion of deaths attributed to pneumonia and influenza as reported by the vital statistics offices of 122 U.S. cities was 6.5% during week 43. This percentage is below the epidemic threshold of 6.9% for this time. Sixteen state and territorial health departments (California, Florida, Georgia, Indiana, Kansas, Kentucky, Missouri, Nevada, New Jersey, New Mexico, New York, Ohio, Pennsylvania, Tennessee, Texas, West Virginia, and Wyoming) reported sporadic influenza activity and 32 reported no influenza activity.

Florida Influenza Surveillance

Data from Florida suggests low levels of influenza activity. As was reported last week, one percent of patients seeking care by physicians in the influenza sentinel surveillance met the case definition for ILI (> 100 F + cough and or sore throat) during week 43. Influenza-like illness activity was detected in 18 counties from Duval to Miami Dade. Higher flu activity than expected for this time of year (>2%) was reported by physicians in Broward, Escambia, Monroe, Palm Beach and Sarasota county. Eight positive influenza tests were reported this week. Influenza A, H3N2 was isolated from a 40-year-old male in Broward County. Positive rapid antigen tests were reported from Duval County (1), Miami-Dade (4) and Volusia Counties (2). Between September 4 and October 27, influenza A (H2N3) was isolated from 4 patients residing in Collier and Palm Beach counties.

Florida Respiratory Syncytial Virus Surveillance

Current data reported from October 26 – November 1, 2001, suggest high levels of RSV activity throughout all regions of Florida. The Florida RSV Surveillance Project analyzes data from four regional areas encompassing 20 sentinel reporting facilities. The four regions performed a total of 429 RSV diagnostic tests with 114 returning positive. This data represents an overall percent positive of 26.6%. Between October 26 and November 1, all four regions reported over 20% positivity rates. Central and Southwest Florida led the regions with 35.5% and 27.3% respectively. Four new hospitals, which are not reflected in the above data, will begin reporting next week.

Investigation of Bioterrorism Related Anthrax and Adverse Events from Antimicrobial Prophylaxis
http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5044a1.htm

Interim Guidelines for Investigation of and Response to Bacillus Anthracis Exposures
http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5044a6.htm

Considerations for Distinguishing Influenza-Like Illness from Inhalational Anthrax
http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5044a5.htm

For additional information regarding bioterrorism preparedness and response see
http://www.bt.cdc.gov/

CDC/NCID/Division of Healthcare Quality Promotion* (*formerly Hospital Infections Program) home page:
http://www.cdc.gov/ncidod/hip

4. Florida West Nile Virus Surveillance Update – 11/08/01

Robin Oliveri, Arbovirus Surveillance Coordinator

*New West Nile Positive Data since last summary report on October 26, 2001.