A fourth Hawaii cyclosporiasis case this year was confirmed in a military service member based in the state, lifting the 2026 total to four.
International travel before the patient fell ill has left investigators unable to determine whether the infection was acquired in Hawaii or abroad.
Health officials said the overall public risk in Hawaii remains low and that they have seen no evidence of local transmission changing that assessment.
The first three 2026 cases also involved travel outside Hawaii—one in a non-resident visitor and two in Hawaii residents who had traveled internationally.
Cyclospora spreads through contaminated food or water, often imported fresh produce, and causes watery diarrhea that can last for weeks without antibiotic treatment.