Cyclospora Outbreak in Michigan: Largest in State History

Current Outbreak Overview

In Michigan, nearly 1,000 individuals have been diagnosed with cyclospora, a parasitic infection causing prolonged watery diarrhea. This outbreak is the largest in state history and one of the nation’s largest in recent years. Thankfully, no deaths have been reported yet. The source of these infections remains unidentified.
Investigations are underway in 28 other states, including Ohio, which has reported cases close to Michigan’s border.

Initial Detection and Spread

Michigan officials first announced the outbreak last week, with over 170 cases reported in the southeastern part of the state since June 22. Typically, Michigan only identifies around 50 cases annually. As of Wednesday, the number increased to 992, with approximately 40 hospitalizations. In Lucas County, Ohio, 306 cases have been documented, contributing to over 400 cases in northwest Ohio.

Challenges in Investigation

Cyclospora outbreaks are complex to investigate. Locating the food poisoning sources is often difficult. However, Dr. Natasha Bagdasarian, Michigan’s chief medical executive, confirmed an ongoing linked outbreak. Cyclospora, a microscopic parasite, spreads through feces. Outbreaks often occur in late spring and summer and are typically managed with antibiotics. Past cases have been connected to contaminated fruits or vegetables.

Comparison with Previous Outbreaks

Complete data on cyclospora outbreaks is limited, but few have surpassed 1,000 cases in the past 20 years. Notable examples include a 1997 outbreak from Guatemalan raspberries affecting over 1,000 people and a 2019 basil-linked outbreak with more than 2,400 cases.

Melanie Firestone, from the University of Minnesota, notes underreporting due to tests not designed to detect cyclospora. The inability to grow the parasite in labs complicates evidence collection from contaminated produce. Identifying a common food source is challenging since a single ingredient can be present in various dishes. Investigations may take months and sometimes remain inconclusive.

Current Situation

Southeastern Michigan reports a surge in cyclospora cases, yet this isn’t classified as a national health emergency. According to Dianna Blau at the CDC, the parasite hasn’t become more infectious. Although thousands of cases are reported each year, the current case total is four times higher than at the same point last year, per the CDC’s national data. Michigan’s thorough reporting might contribute to the perception of a localized issue.

Protecting Yourself from Cyclospora

If diarrhea persists for several days, seek medical advice regarding cyclospora. To prevent infection, avoid possibly contaminated food or water. Thoroughly wash fresh produce before consumption. Cyclospora can adhere strongly to foods, so washing may not completely eliminate risks. Michigan officials suggest purchasing whole heads of lettuce rather than bagged mixes and washing remaining leaves under running water after removing the outer ones. Cooking vegetables, when possible, is also recommended.

_The Associated Press Health and Science Department is supported by the Howard Hughes Medical Institute’s Department of Science Education and the Robert Wood Johnson Foundation. The AP maintains sole responsibility for all content._