Fourth case of the intestinal illness cyclosporiasis confirmed in Hawaiʻi

The Hawaiʻi Department of Health has confirmed a case of cyclosporiasis in a member of the military based in the state.

The individual traveled internationally before returning to Hawaiʻi prior to getting sick. Based on the person’s travel history, symptom onset and the known incubation period, it is not known at this time if the infection was acquired in Hawaiʻi or while traveling.

But at this point in the health department’s investigation, there is no evidence that this case changes the low risk assessment of cyclosporiasis to the public in Hawaiʻi.

This case brings the total number of confirmed cyclosporiasis cases reported in Hawaiʻi in 2026 to four. The first case involved a non-resident visitor whose infection also was acquired outside of Hawaiʻi. The next two cases involved two Hawaiʻi residents who traveled internationally.

Cyclosporiasis is an intestinal illness caused by the microscopic parasite Cyclospora cayetanensis. Eggs of the parasite shed in the feces of infected persons and must mature outside the host, in the environment, before they become infectious to another person.

People become infected by consuming food or water contaminated with the parasite. In the United States, outbreaks have most often been linked to certain fresh produce items. The illness is not typically spread directly from person to person.

Symptoms usually begin about one week after exposure but can appear anywhere from two days to two weeks later. The most common symptom is frequent, watery diarrhea. Other symptoms may include loss of appetite, weight loss, stomach cramps or bloating, nausea, increased gas, fatigue and, less commonly, vomiting or low-grade fever. Without treatment, symptoms may last for several weeks or longer and can come and go.

The DOH routinely investigates reportable diseases to identify potential sources of infection and monitors for any signs of local transmission.

People can help reduce their risk of cyclosporiasis by:

• Washing hands thoroughly with soap and water before preparing or eating food and after using the restroom.
• Washing fresh fruits and vegetables under running water before eating, cutting or cooking them.
• Following safe food handling practices when preparing meals.
• Seeking medical care if they experience prolonged or severe diarrhea, particularly after recent travel or eating fresh produce from an area associated with an outbreak.

Cyclosporiasis is treatable with prescription antibiotics. Individuals experiencing persistent diarrhea should contact their healthcare provider. Healthcare providers who suspect cyclosporiasis are encouraged to report cases to the DOH and submit appropriate specimens to commercial laboratories for testing.

The DOH will continue to monitor for additional cases and work closely with healthcare providers and public health partners to protect the health of Hawaiʻi residents and visitors.

For more information about cyclosporiasis, the Hawaiʻi Department of Health Disease Outbreak Control Division website.