The West Virginia Bureau for Public Health announced Sunday that its investigation into cyclosporiasis had expanded, with case numbers climbing beyond the 47 confirmed infections reported on July 10. Investigators are working to trace a suspected food source.

Cyclosporiasis is caused by the Cyclospora cayetanensis parasite, which spreads through contaminated food or water and produces prolonged watery diarrhoea, fatigue and cramping. The illness is commonly linked to imported fresh produce during summer months, with cases typically rising across the United States in June and July.

The state agency is advising residents experiencing persistent diarrhoea lasting more than a few days to seek medical care. The infection requires specific antibiotic treatment rather than standard anti-diarrhoeal medicines.

Laboratory testing is ongoing to confirm suspected cases and identify a common exposure. The West Virginia cluster follows warnings from the U.S. Centers for Disease Control and Prevention about seasonal cyclosporiasis tied to contaminated produce. The CDC has tracked hundreds of domestically acquired cases in recent summers, frequently linked to leafy greens, herbs and berries.

A spokesperson for the West Virginia Bureau for Public Health urged clinicians to consider Cyclospora when testing patients with prolonged gastrointestinal symptoms and to report suspected cases promptly to support the outbreak investigation.