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Epidemiologic Notes and Reports Cholera -- New Jersey and Florida

Through April 30, 1991, epidemic cholera has been reported from five countries in South America: Brazil, Chile, Colombia, Ecuador, and Peru. In addition, in the United States a total of 10 confirmed cases of epidemic-associated cholera have been reported in Georgia (1), New Jersey, and Florida. This report summarizes information regarding the cases reported in New Jersey and Florida. New Jersey

From March 31 through April 3, eight residents of Hudson and Union counties developed profuse watery diarrhea after eating crab meat transported from South America. Five of the patients also reported vomiting, and at least three had severe leg cramps; five were hospitalized. Ingestion of the crab meat was statistically associated with illness; of the 11 persons who attended the two meals where the crab was served, all eight who ate the crab meat became ill; the three who did not remained well (p less than 0.01). Each of the patients had onset of symptoms within 3 days of ingesting the crab meat. Stool samples from four of the eight patients yielded toxigenic Vibrio cholerae O1, serotype Inaba, biotype El Tor, the same serotype responsible for the epidemic in South America. In convalescent serum specimens obtained from the four patients who were culture negative, vibriocidal antibody titers were greater than or equal to 1:1280, indicating recent V. cholerae infection.

The crab was purchased in a fish market in Ecuador, then boiled, shelled, and wrapped in foil. On March 30, it was transported into the United States, unrefrigerated, in a plastic bag on an airplane. It was delivered to a private residence, refrigerated overnight, then served in a salad on March 31 and April 1. No crab meat was available for culture.

All eight patients have fully recovered. No cases of secondary transmission have been reported. Florida

On April 6, a woman with severe watery diarrhea was admitted to a Dade County hospital on her return from Ecuador. Although stool cultures were negative for V. cholerae O1, testing of acute and convalescent blood samples detected a 32-fold rise in vibriocidal antibody titers, indicating recent infection with V. cholerae O1.

The patient had traveled in Ecuador from March 27 through April 6. She reported eating raw oysters in Salinas Beach, Ecuador, on March 29 and ceviche on March 30; she also consumed ice during her stay. On April 2, she developed watery diarrhea with 30-40 stools per day. On return to the United States, she was admitted to the hospital. The patient recovered, and no cases of secondary transmission have been identified. Reported by: H Ragazzoni, DVM, K Mertz, MD, L Finelli, DrPH, C Genese, MBA, Div of Epidemiology, FJ Dunston, MD, State Commissioner of Health, New Jersey State Dept of Health. B Russell, MPH, W Riley, PhD, E Feller, MD, Baptist Hospital, Miami; MB Ares, MD, M Fernandez, MD, E Sfakianaki, MD, Dade County Public Health Unit; JA Simmons, MD, RS Hopkins, MD, State Epidemiologist, Florida Dept of Health and Rehabilitative Svcs. Enteric Diseases Br, Div of Bacterial and Mycotic Diseases, Center for Infectious Diseases, CDC.

Editorial Note

Editorial Note:

Epidemic cholera had not been reported in South America this century (2) until January 1991, when cholera appeared simultaneously in several coastal cities of Peru. As of April 29, 169,255 probable cholera cases and 1244 deaths in Peru had been reported to the Pan American Health Organization; cholera had also been reported in Ecuador (3898 cases and 140 deaths), Chile (26 cases), Colombia (176 cases), and Brazil (four cases). The cases reported in Florida and New Jersey bring to 10 the total number of confirmed cases in the United States associated with the epidemic in South America.

No reported cases of cholera have been linked to commercially imported food products. In New Jersey, the confirmed V. cholerae O1 infections resulted from consumption of noncommercial crab meat that had been grossly mishandled and illegally transported into the United States. Although it is unclear how the crab meat became contaminated, contamination may have occurred at harvest, at purchase, or after cooking. V. cholerae O1 can survive in contaminated crabs that are boiled for less than 10 minutes (3). Because V. cholerae biotype El Tor strains multiply rapidly at room temperature in cooked shellfish (4), the lack of refrigeration during transport may have permitted growth of vibrios.

Previous cases acquired in the United States have been associated with undercooked crabs or raw oysters harvested domestically in the Gulf of Mexico (3,5). In the United States, secondary transmission from imported or domestic cases is unlikely because of the availability of safe drinking water and proper treatment of sewage.

The risk for cholera to tourists in affected areas is considered extremely low (6). Although it cannot be determined whether the source of infection in the traveler to Ecuador was consumption of raw oysters, ceviche, or contaminated ice or some other vehicle of infection, this case illustrates the need for travelers to areas with epidemic cholera to follow scrupulously the precautions described for prevention of travelers' diarrhea (7). The general rule "boil it, cook it, peel it, or forget it" has been proposed for preventing travelers' diarrhea (8). In particular, travelers to Colombia, Ecuador, and Peru should not consume 1) unboiled or untreated water and ice made from such water; 2) food and beverages from street vendors; 3) raw or partially cooked fish and shellfish, including ceviche; and 4) uncooked vegetables. Travelers should eat only foods that are cooked and hot, or fruits they peel themselves. Carbonated bottled water and carbonated soft drinks are usually safe if no ice is added. Cholera vaccination, which protects approximately 50% of vaccinated persons for 3-6 months, is not recommended for travelers and is not a substitute for scrupulously choosing food and drink.

V. cholerae may not be isolated from stool samples of cholera patients if the samples are collected late in illness or after antimicrobial therapy is begun. Vibriocidal antibody titers peak 10-21 days after infection and can be used to confirm V. cholerae infection (9).

Travelers who develop severe watery diarrhea, or diarrhea and vomiting, during or within 1 week after travel to an area with known cholera should seek medical attention immediately. Physicians should request that specimens from suspected cases be cultured on media designed for isolation of V. cholerae and should report suspected cases of cholera to their local and state health departments.


  1. CDC. Importation of cholera from Peru. MMWR 1991;40:258-9.

  2. CDC. Cholera--Peru 1991. MMWR 1991;40:108-10.

  3. Blake PA, Allegra DT, Snyder JD, et al. Cholera--a possible endemic focus in the United States. N Engl J Med 1980;302:305-9.

  4. Kolvin JL, Roberts D. Studies on the growth of Vibrio cholerae biotype El Tor and biotype classical in foods. J Hygiene 1982;89:243-52.

  5. Pavia AT, Campbell JF, Blake PA, Smith JD, McKinley TW, Martin DL. Cholera from raw oysters shipped interstate. JAMA 1987;285:2374.

  6. Snyder JD, Blake PA. Is cholera a problem for US travelers? JAMA 1982;247:2268-9.

  7. CDC. Health information for international travel, 1990. Atlanta: US Department of Health and Human Services, Public Health Service, 1990; DHHS publication no. (CDC)90-8280.

  8. Kozicki M, Steffen R, Schar M. Boil it, cook it, peel it or forget it: does this rule prevent travellers' diarrhoea? Int J Epidemiol 1985;14:169-72.

  9. Feeley JC, DeWitt WE. Immune response to Vibrio cholerae. In: Rose NR, Friedman H, eds. Manual of clinical immunology. Washington, DC: American Society for Microbiology, 1976:289-95.

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