Hawaii health officials found dengue virus in a Hilo wastewater sample, an early warning sign for the Big Island even though no one there is currently sick with it.

• A routine wastewater test in Hilo came back positive for dengue.
• There are no active dengue cases on the Big Island right now.
• Hawaii has had seven dengue cases this year, all picked up by travelers abroad.
• People returning from overseas trips are told to watch for fever and nausea.

Outlook: Health officials will keep testing wastewater and tracking travelers for symptoms to catch any local spread early.