The Return of Cyclospora in 1997: Another Outbreak of Cyclosporiasis in North America Associated with Imported Raspberries

2 February 1999 | Volume 130 Issue 3 | Pages 210-220

Background: In the spring of 1996, an outbreak of cyclosporiasis associated with fresh Guatemalan raspberries occurred in the United States and Canada. Another multistate outbreak of cyclosporiasis occurred in North America in the spring of 1997.

Objective: To identify the vehicle of the outbreak that occurred in the spring of 1997.

Design: Retrospective cohort studies of clusters of cases associated with events (such as banquets) and traceback investigations of sources of implicated produce.

Setting: United States and Canada.

Patients: Persons who attended events associated with clusters of cases of cyclosporiasis.

Measurements: Identification of clinically defined or laboratory-confirmed cases of cyclosporiasis and risk factors for infection.

Results: 41 clusters of cases were reported in association with events held from 1 April through 26 May in 13 U.S. states, the District of Columbia, and 1 Canadian province. The clusters comprised 762 cases of cyclosporiasis, 192 (25.2%) of which were laboratory confirmed. In addition, 250 laboratory-confirmed sporadic cases were reported in persons who developed gastrointestinal symptoms from April through 15 June, for a total of 1012 cases. Fresh raspberries were the only food common to all 41 events and were the only type of berry served at 9 events (22.0%). Statistically significant associations between consumption of raspberry-containing items and cyclosporiasis were documented for 15 events (40.5% of 37). For 31 of the 33 events with well-documented traceback data, the raspberries either definitely came from Guatemala (8 events) or could have come from Guatemala (23 events). The mode of contamination of the raspberries remains unknown. The outbreak ended shortly after the exportation of fresh raspberries from Guatemala was voluntarily suspended at the end of May 1997.

Conclusions: Similar multistate, multicluster outbreaks of cyclosporiasis associated with consumption of Guatemalan raspberries have occurred in consecutive years. These outbreaks highlight the need for better understanding of the biology and epidemiology of Cyclospora cayetanensis and for stronger prevention and control measures to ensure the safety of produce eaten raw.

*For a list of the members of the Cyclospora Working Group, see the Appendix.

Author and Article Information

From the Centers for Disease Control and Prevention, Atlanta, Georgia.

Acknowledgments: The authors thank the many persons and institutions, including but not limited to the following, who assisted with the investigation (asterisks denote members of the Epidemic Intelligence Service, Epidemiology Program Office, CDC).

California: Carol Greene (California Department of Health Services); Alfonso Medina, BS (Los Angeles County Department of Health Services); and Michael Hartley, BS, MS (Santa Barbara County Health Care Services).

Connecticut: Quyen N. Phan, MPH (Connecticut Department of Public Health).

Florida: Florida Department of Health.

Illinois: Frances Eury, RN, BSN, MPH (City of Evanston Health Department); and Margaret Swartz, RN, and Constance C. Austin, DVM, PhD (Illinois Department of Public Health).

Maryland: Carmela Groves, RN, MS (Maryland Department of Health and Mental Hygiene); and Joan Purvis, BS, RN (Montgomery County Department of Health and Human Services).

Massachusetts: Vinkey Moroak, Dianne Morris, MD, and Emily L. Harvey (Massachusetts Department of Public Heath); and Kate Matthews, BA, RN, Donna Caron, RN, MSN, and Pat Tormey, RN, MPH (Boston Public Health Commission).

Nebraska: Roseann Mastio, RN, and Yoke-ha Fisher, MSc (Douglas County Health Department).

New Hampshire: Richard Di Pentima (New Hampshire Department of Health and Human Services).

New York: Teresa Briggs, MD, PhD (Albany County Health Department); Maryann Trupei, RN, and Nancy Bennett, MD, MS (Monroe County Department of Health); William Gehrhardt, MD, Joanne Maniscalco, BSN, Barbara Rowan, BA, RS-REHS, Mark Schwartz, MPA, CIC, Margaret Sherman, BSN, and Elaine Yeoman, BSN (Nassau County Department of Health); Elizabeth A. Griffin, MPH, Adeleh Ebrahimzadeh, PhD, Awilda Colon-Serrant, MPH, and Marcelle Layton, MD (New York City Department of Health); Anne Marie Andolina, BA, Annette Polk, and Perry F. Smith, MD (New York State Department of Health); Julie Jacobs, SPHN (Westchester County Department of Health); Hameed Quraishi, PhD (Chelsea Biologics); John Asher, MD (Jetti Katz Tropical Disease Laboratory); Renate F. Klein, PhD (The New York Hospital-Cornell Medical Center); and Yvonne A. Lue, PhD (Quest Diagnostics).

Pennsylvania: Andre C. Weltman, MD, MSc (Pennsylvania Department of Health).

Rhode Island: Ernest Julian, PhD, Linda M. Tetu-Mouradjian, RN, and Edward Donnelly, RN, MPH (Rhode Island Department of Health).

Texas: Texas Department of Health and Houston Department of Health and Human Services.

Vermont: Susan Schoenfeld, RN, MSPH, and Jan K. Carney, MD, MPH (Vermont Department of Health).

Wisconsin: Mary Jo Trepka, MD*, and Thomas Haupt, MS (Wisconsin Department of Health and Family Services).

United States: Suzanne Binder, MD, Dennis D. Juranek, DVM, MSc, Allen W. Hightower, MS, Thomas R. Navin, MD, Michael Sabat, MS, and Mary E. Bartlett, BA (Division of Parasitic Diseases, National Center for Infectious Diseases, CDC); Andrew R. Pelletier, MD (Epidemiology Program Office, CDC); Jennifer M. Donzanti, BS, Rebecca R. Hackett, BS, Patrick McCarthy, PhD, MPH, Maria A. Medina, AA, Philippe L. Noisin, BS, Deborah D. Ralston, AB, Luiz Solorzano, BS, Carl I. Vassar, BS, and the District Offices in Baltimore, Buffalo, Chicago, Cincinnati, Dallas, Florida, Kansas City, Los Angeles, New England, New Orleans, New York, Philadelphia, and San Francisco (Office of Regulatory Affairs, U.S. Food and Drug Administration).

Requests for Reprints: Barbara L. Herwaldt, MD, MPH, Division of Parasitic Diseases, Centers for Disease Control and Prevention, 4770 Buford Highway NE, Mailstop F22, Atlanta, GA 30341-3724.

Current Author Addresses: Drs. Herwaldt and Beach: Division of Parasitic Diseases, Centers for Disease Control and Prevention, 4770 Buford Highway NE, Mailstop F22, Atlanta, GA 30341-3724.