Hawaii health officials are looking into what may be the first case of the parasite Cyclospora caught on Oahu itself, a worrying sign for local food safety.

• An Oahu resident got sick in late July without leaving Hawaii, pointing to exposure on the island.
• Every earlier case in the state was traced to travel or food from outside Hawaii.
• Cyclospora is a parasite usually spread through contaminated fresh produce or water.
• A confirmed local case would mean the source is somewhere in Hawaii's own food or water supply.

Outlook: Health officials will keep investigating to pin down the source, and more cases could surface if it is local.