Public health officials warned Americans on Saturday to take precautions against cyclosporiasis, a parasitic intestinal infection linked to fresh produce, as case counts rose across several states during the peak summer season. The Oregon Health Authority reported an increase in confirmed infections in June.

Cyclosporiasis is caused by the parasite Cyclospora cayetanensis and produces symptoms including watery and explosive diarrhoea, cramping, fatigue and weight loss. The illness spreads through contaminated food and water, and past US outbreaks have been traced to imported fresh herbs and salad greens, according to the Centers for Disease Control and Prevention.

The Oregon Health Authority said the June figures were consistent with the seasonal pattern seen most years, when infections cluster between May and August. Most cases are not linked to local transmission but to produce imported from regions where the parasite is endemic.

The CDC advised consumers to wash fruit and vegetables thoroughly, though it cautioned that washing may not fully remove the parasite. Physicians noted that cyclosporiasis can be treated effectively with antibiotics such as trimethoprim-sulfamethoxazole, and urged people with prolonged diarrhoea to seek testing.

Health agencies said surveillance would continue through the summer, with the CDC coordinating with state laboratories to identify any common food source. Clinicians have been asked to report suspected cases promptly to help trace potential outbreak clusters.