DOH: Dengue virus detected in wastewater from Hawaii Island
A wastewater sample from Hawaii County has tested positive for the dengue virus, according to the state Department of Health.
Read more Ka‘u students return to in-person learning in aftermath of Lala
The sample was collected Aug. 24 at the Hilo wastewater treatment plant, and DOH was notified of the result on Monday.
A follow-up sample was collected Monday, and those results are pending. DOH is not currently tracking any active dengue cases in Hawaii County.
Dengue virus is transmitted from an infected person to a mosquito and then to another person. While Hawaii is home to mosquitoes that can carry dengue, the disease is not endemic, or established, in the state.
All dengue cases reported in Hawaii to date have been travel-associated. Of the seven dengue cases reported in Hawaii in 2026, all have involved travel to Pacific Island countries and territories.
Dengue is a year-round risk in tropical and subtropical areas of Central and South America, including Brazil and Mexico; Asia, including the Philippines; the Middle East; Africa; and several Pacific islands, including American Samoa, the Federated States of Micronesia, the Republic of the Marshall Islands and the Republic of Palau. Many popular tourist destinations in the Caribbean, including Puerto Rico, are also affected. Some countries are reporting higher-than-usual numbers of dengue cases, including Bolivia, Colombia, Samoa, Tonga, New Caledonia, Cambodia, Malaysia, Vietnam, the Maldives, Sri Lanka and Kenya.
Travelers returning from areas with dengue risk should take precautions to prevent mosquito bites for three weeks. If dengue symptoms develop within two weeks of returning, travelers should seek medical evaluation.
Read more The Big Ten’s biggest storylines as the hunt for a fourth straight national title begins
Symptoms of dengue can range from mild to severe and include fever, nausea, vomiting, rash and body aches. Symptoms typically last two to seven days.
While severe illness can occur, most people recover within a week.
Individuals who have recently traveled and are experiencing these symptoms should contact their healthcare provider. Healthcare providers and individuals who suspect dengue infection are advised to call the Disease Reporting Line at (808) 586-4586.
Hawaii collects municipal wastewater samples each week and sends them to the State Laboratories Division for testing, as well as to the University of Missouri for advanced sequencing to look for bacterial and viral genetic material associated with community infections.
Wastewater sampling is routinely conducted across Hawaii to support infectious disease surveillance.
According to the DOH, a dengue signal in wastewater does not confirm a clinical case or indicate community transmission. Instead, it serves as an early indicator that can prompt awareness and monitoring for potential cases.
