Washington health officials have confirmed 27 provisional cases of cyclosporiasis since May 1, but they say the infections are not linked to the ongoing multistate outbreak being investigated across the United States. State officials also stressed that Washington is not experiencing its own outbreak of the illness.
The Washington State Department of Health released the latest update on Wednesday. The report provides an overview of cases identified in the state while explaining that current findings do not show a connection to outbreaks reported elsewhere in the country.
According to the department, 27 provisional cases have been reported in Washington since May 1, 2026. Most of those infections were linked to international travel rather than local transmission.
Health officials said 22 people had recently traveled to countries where the parasite is commonly found. Three cases were acquired within the United States and were not connected to travel. Two additional cases remain under review because investigators have not been able to confirm the patients’ travel history.
The department also reported that none of the patients have required hospitalization and no deaths have been linked to the illness in Washington.
State officials emphasized that none of the reported infections are associated with the multistate outbreak currently under investigation by federal health authorities. They also noted that some cases are still being reviewed and that county-level data is not being released because the numbers remain provisional.
The Centers for Disease Control and Prevention continues to investigate the larger outbreak affecting multiple states. So far, investigators have not identified the source of the infections. Because reported cases have increased in recent weeks, the agency plans to provide more frequent public updates during the current surveillance season.
Cyclosporiasis is an intestinal illness caused by the microscopic parasite Cyclospora cayetanensis. People become infected after eating food or drinking water contaminated with the parasite.
Unlike many common stomach illnesses, cyclosporiasis is not usually spread directly from one person to another. The parasite must spend several days or even weeks in the environment before it becomes capable of infecting another person.
The disease is found in many parts of the world but is more common in tropical and subtropical regions. These include parts of Latin America, sub-Saharan Africa, the Indian subcontinent, Southeast Asia, and Egypt. In the United States, past outbreaks have often been linked to imported fresh fruits and vegetables or to international travel.
Symptoms usually begin about one week after a person becomes infected. The illness most often causes frequent watery diarrhea, which can sometimes be severe. Other common symptoms include stomach cramps, bloating, nausea, vomiting, loss of appetite, weight loss, tiredness, and a low fever.
Without treatment, symptoms may continue for several weeks or even months. Some people experience periods where symptoms improve before returning again. Doctors can diagnose the infection through laboratory testing, and effective treatment is available with prescription medication.
Federal health officials continue to monitor the national situation closely. According to the CDC, 843 domestically acquired cases have been confirmed across 31 states since May 1. The agency has also reported 86 hospitalizations related to the outbreak, but no deaths have been recorded.
In addition to the confirmed cases, the CDC is reviewing more than 1,500 reports from across the country. Investigators are working to determine whether those reports meet the official case definition before they are added to the national total.
Health officials continue to encourage people to practice good food safety by washing fresh produce, using safe drinking water, and seeking medical care if they experience prolonged diarrhea or other symptoms consistent with cyclosporiasis. While the national investigation continues, Washington officials say current evidence shows the state’s reported cases remain separate from the broader multistate outbreak.
