A wastewater sample pulled from an East Kauaʻi site earlier this month has come back positive for H5N1 avian influenza, marking the first time that particular genotype has ever turned up in Hawaiʻi. State health officials say the finding, confirmed through genomic sequencing, does not mean anyone or any flock on the island is currently sick, but it is prompting closer monitoring across the state.
The sample was collected on Oct. 14, and the Hawaiʻi Department of Health was notified of the positive result on Oct. 26, according to KITV. Genomic sequencing performed by the University of Missouri identified the genetic material as genotype D1.1, which the Maui Now reported is a first for the state. It is also the first H5N1 detection in Hawaiʻi tied to this year's seasonal bird migration, per the same station's reporting.
Officials were careful to frame what the result does and does not show. The station's report notes that an H5 detection does not confirm a clinical case or indicate community transmission, calling it instead an early indicator that can prompt increased awareness and monitoring. Detecting H5 genetic material in wastewater does not mean live, infectious virus is present, and testing cannot determine whether the material came from an animal, a person, or environmental contamination, the outlet reported.
Why an Open Wastewater System Complicates the Picture
Part of the uncertainty comes down to how the East Kauaʻi plant operates. It is an open system, meaning the detection could be associated with contaminated products or waste from infected animals or people, the same report states. That ambiguity is echoed in earlier Kauaʻi findings: as reported by Kauai Now, consistent very low H5 detections at the Līhuʻe Wastewater Treatment Plant in January 2025 suggested a high likelihood that bird flu virus was already present on the island, even though no individual sample was deemed positive at the time.
Nathan Tan, the state's deputy state epidemiologist, said the risk to the public remains low, according to a statement reported by Hawaii News Now. Tan also addressed dairy safety directly, saying pasteurized milk is safe to consume while raw milk should be avoided, per that outlet.
No Sick Birds or Dairy Contamination Reported So Far
On the agricultural side, the state has not logged any avian influenza cases among wildlife or domestic poultry so far this year, the Star-Advertiser reported. DOH has also continued testing milk from local dairies and has not found any H5N1 detections in that supply, the station's reporting notes. Genotype D1.1 itself, however, is no stranger to the broader U.S. outbreak: it has become the predominant strain found in infected wildlife and domestic poultry nationally, and it has infected dairy cattle in isolated events elsewhere in the country, as reported by the Star-Advertiser.
Hawaiʻi's prior experience with bird flu involved a different strain. The state's first avian influenza outbreak was detected in November 2024 at Susie's Duck Sanctuary, and that outbreak involved genotype A3, the previously detected strain in Hawaiʻi, according to the Star-Advertiser's reporting. The arrival of D1.1 represents new territory for the islands rather than a continuation of that earlier event.
What Comes Next for Testing and Monitoring
Wastewater surveillance for H5 avian influenza continues in other Hawaiʻi counties through national and state monitoring networks, and the state's health department relies on routine sampling as part of its broader infectious disease surveillance work. Beyond Hawaiʻi, the pattern of wastewater catching signals before any confirmed outbreak is not new — a CDC report on Oregon surveillance data found avian influenza A(H5) detected in communities with no concurrent outbreaks at dairy facilities or farms, illustrating how wastewater can flag a virus's presence well ahead of, or even in the absence of, a confirmed case.
For now, state officials are treating the Kauaʻi finding as a signal to watch rather than a confirmed outbreak. The open questions around the source of the genetic material, and whether it reflects an infected bird, animal, or simply environmental contamination, remain unresolved based on current reporting.
