Michigan has recorded nearly 1,000 confirmed cases of a parasitic infection that causes prolonged watery diarrhoea, marking the largest Cyclospora outbreak in the state’s history.
Health authorities said on Wednesday that 992 people had been diagnosed with the infection, with about 40 requiring hospital treatment. No deaths have been reported.
The source of the outbreak remains unknown, while investigations are also underway into similar illnesses reported in 28 other U.S. states, including neighbouring Ohio.
Michigan health officials first announced the outbreak last week after identifying more than 170 cases in the southeastern part of the state since June 22.
The state typically records only about 50 Cyclospora infections annually.
Across the border, Lucas County in Ohio had reported 306 confirmed cases by Wednesday, while northwestern Ohio has recorded more than 500 infections overall.
Michigan’s Chief Medical Executive, Dr Natasha Bagdasarian, said health authorities believed the cases were linked.
“There is clearly a linked outbreak happening right now,” she said.
According to the U.S. Centers for Disease Control and Prevention (CDC), Cyclospora is a microscopic parasite that infects the intestines and causes cyclosporiasis, a disease characterised by watery diarrhoea that can include frequent and, at times, explosive bowel movements.
The illness is generally not life-threatening and is usually treated with antibiotics.
Cyclospora infections occur more frequently during the late spring and summer months.
The parasite spreads through faecal contamination, often when people consume fresh fruits or vegetables exposed to contaminated irrigation water.
Although less common than foodborne illnesses such as salmonella and Escherichia coli (E. coli), Cyclospora outbreaks have become more frequent in the United States over the past decade.
Public health experts attribute the increase to improved detection methods as well as the effects of climate change, with particularly large outbreaks recorded in 2018 and 2019.
