State health officials are trying to pinpoint the source of a growing parasitic outbreak in Michigan, contacting all people who’ve tested positive for cyclosporiasis as cases near 1,000.
Since the outbreak started June 22, 992 reports of cyclosporiasis have been reported in Michigan as of Wednesday morning, according to the state’s Department of Health and Human Services, up from 708 cases on Monday evening.
The outbreak is now the largest of the parasitic illness that Michigan has ever had, said Dr. Natasha Bagdasarian, the state’s chief medical executive.
No specific produce grower, supplier or type of produce has been identified as the source of the outbreak, which has been reported in at least 21 counties, but the state health department has launched a webpage where case counts will be updated daily.
Cyclosporiasis is a parasitic illness that usually causes frequent, watery and explosive diarrhea. People can get infected by consuming food or water that contains the parasite.
While state officials have yet to identify a common source that’s infecting patients, Bagdasarian told The Detroit News on Tuesday that state health officials “definitely are moving closer to identifying a source.”
But there’s “nothing definitive” at this point, she said.
State health officials form a theory for outbreak
Bagdasarian said the state health department’s current leading hypothesis is that the outbreak is likely related to produce. Previous outbreaks of Cyclospora in the United States and Canada have been associated with bagged lettuce kits, raspberries, cilantro, green onions and snow peas.
To find the culprit this time, Bagdasarian said local health departments, with the support of state staff, have been reaching out to individuals who have tested positive for Cyclospora and interviewing them about their food exposures.
State epidemiologists examine the data collected from these interviews and look for “any flags,” she said.
“They’re looking for any commonalities, for any common sources between these individuals, either based on location, locations of restaurants, locations of grocery stores, types of produce,” Bagdasarian said, “so they are doing a huge amount of cross-checking there.”
Michigan Department of Health and Human Services spokesperson Lynn Sutfin said, at this time, no specific produce grower, supplier or type of produce has been identified as the source.
“Anyone experiencing gastrointestinal illness, such as sudden and ongoing diarrhea, should contact their health care provider and their local health department,” Sutfin said in an email.
Bagdasarian said the U.S. has previously had outbreaks of cyclosporiasis, some of which have reached as many as around 1,000 or 2,000 cases nationally.
“This one has been alarming in how quickly the number of cases has increased in Michigan alone,” she said.
Tracking the outbreak by talking to patients
State health officials first flagged the sudden surge in cyclosporiasis cases in late June.
Bagdasarian said that when a positive test result for Cyclospora goes into the state health department’s disease monitoring system, local health departments or state staff will contact the individual. They administer a questionnaire that asks about food exposures, including about restaurants and grocery stores the individual has visited. It also asks which groceries were purchased, including specific brands of produce.
That information is entered into spreadsheets, which go to the state Department of Health and Human Services. State epidemiologists then look at the data.
In Oakland County, members of the health division’s 10-person communicable disease unit are investigating every case of cyclosporiasis reported in the county. As a reportable illness in Michigan, it’s required.
Those who’ve tested positive for the parasite are interviewed to determine potential exposure sources, such as foods consumed, restaurants, stores, events, or travel, said Oakland County Health Officer Kate Guzman in an emailed statement.
Bagdasarian said the department’s Bureau of Laboratories, meanwhile, has the capacity to do whole genome sequencing, or genetic fingerprinting, of the Cyclospora organism. The bureau has been testing some of the isolates, or samples, of Cyclospora to “look for genetic clues at how closely the isolates are matched,” she said.
“And that gives us an idea of whether there was a common source and whether folks could have been exposed from eating the same meal or the same product,” Bagdasarian said.
How local restaurants are responding to outbreak
Justin Winslow, president and CEO of the Michigan Restaurant and Lodging Association, said in a statement that Michigan restaurant operators take “food safety and the role they take in public health seriously.”
“State law mandates that every restaurant have at least one manager trained in food safety on their staff, and every one of our members are also pillars of their communities,” he said. “They plan for prevention of foodborne illness regardless of public health threats to keep their communities and families safe.”
Winslow said his organization provides ServSafe training to its members at a discounted rate, and the training can be applied to new public health concerns “with little change.”
Expert speculates on what may be causing outbreak
The source of the outbreak could be a worker in a farm field or someone doing the processing of the food, said Ewen Todd, a consultant who contributes to a food safety master’s course at Michigan State University. The source could also be irrigation water that has been infected by Cyclospora, he said.
“It’s really hard to identify the source, the actual source,” Todd said.
Todd, a former director of the National Food Safety and Toxicology Center at Michigan State, said people with cyclosporiasis get watery diarrhea but can have other symptoms as well, such as gastrointestinal pain. The symptoms could “go on for quite a while,” perhaps several weeks, he said.
“And it might come and go as well,” Todd added.
Dr. Anil Sharma, an associate professor in the Division of Gastroenterology, Hepatology and Nutrition at the University of Florida College of Medicine, said that before patients are treated, they should get a stool test to confirm if they have the illness. If a doctor strongly suspects patients are infected, they may need to repeat the test, as they could test negative initially, he said.
Sharma said the parasite is treated with an antibiotic, Bactrim DS.
It’s “very effective in this infection,” he said.
asnabes@detroitnews.com
This article originally appeared on The Detroit News: Michigan officials race to find cause of parasitic outbreak as cases near 1,000
Reporting by Anne Snabes, The Detroit News / The Detroit News
USA TODAY Network via Reuters Connect
By Anne Snabes, The Detroit News | USA TODAY Network
