HONOLULU — The Hawaiʻi Department of Health (DOH) is monitoring a positive wastewater sample for measles virus, the first wastewater detection of the virus for Kauaʻi County. The sample was collected Sept. 24, 2025, at a site in East Kauaʻi County and DOH was notified of the result on Oct. 20, 2025. No suspected measles cases have been identified on Kauaʻi.

Each week, municipal wastewater samples from across Hawaiʻi are sent to the University of Missouri for deep sequencing to identify bacterial and viral genetic material associated with community infections. Recently, sequencing data revealed the presence of the measles virus genotype D8 sequence in a sample collected from Kauaʻi County on Sept. 24, 2025. Genotype D is found in wild measles virus; measles vaccines use genotype A. Additional sequencing results are expected by the end of this week.

Wastewater sampling is routinely conducted across Hawaiʻi as part of infectious disease surveillance. It can detect viral genomic material shed by infected individuals, even if they are not showing symptoms or have not reported illness. The presence of measles virus in wastewater does not confirm a clinical case or community spread. Instead, it serves as a reliable indicator to be alert for possible measles cases.

The State Laboratories Division (SLD) will continue to monitor and test wastewater samples to support early detection and public health preparedness.

Measles also is being monitored in wastewater by the National Wastewater Surveillance System (NWSS) and WastewaterSCAN.

The DOH urges everyone to stay up to date on the measles, mumps and rubella (MMR) vaccine. Measles is highly contagious but preventable through vaccination. Infants under 1 year of age are at particularly high risk because they are too young to be vaccinated, but in certain situations, vaccination may be recommended for children between 6 and 12 months if they are exposed to a known case. To get an MMR vaccine, contact your medical provider or pharmacy.

If you traveled to an area with a current measles outbreak, speak with your doctor if you develop symptoms. International and U.S. locations are still experiencing cases of measles, with 42 states reporting cases as of Oct. 21, 2025. The DOH will issue a medical advisory to healthcare providers statewide with information on how to test for measles and current vaccination recommendations.

Measles symptoms usually start with a high fever, cough, runny nose and red eyes, followed by a rash of tiny red sports that begins at the head and spreads downward. The disease can lead to serious complications, including pneumonia, neurological illness and death.

If you think you have symptoms of measles or were exposed to someone with measles, isolate yourself immediately and contact your healthcare provider for guidance to avoid further spread.

ABOUT DOH WASTEWATER TESTING

The SLD wastewater testing program is collaborating with a laboratory at the University of Missouri through a project that advances the detection of infectious disease pathogens in the environment. This national effort aims to strengthen environmental monitoring of air and water as a means to detect, forecast and contain pathogen outbreaks and other biological threats. As part of the project, wastewater samples from sites across the country, including Hawaiʻi, are analyzed to characterize viruses present spanning those that infect humans, animals, plants and microbes.

For more information about measles, visit:

DOH measles information website

CDC measles website

MMR vaccine factsheet

Wastewater Data for Measles | National Wastewater Surveillance System | CDC

WastewaterSCAN Dashboard

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