State health officials have confirmed a second detection of the measles virus in wastewater from West Maui, though no measles cases have been identified in Hawaii.

The positive sample was collected Nov. 30 and tested through the National Wastewater Surveillance System, the Hawaii Department of Health said Thursday.

The alert follows an earlier detection from samples taken Nov. 18 in Central and West Maui. Subsequent samples collected Nov. 24 and 25 from the West Maui treatment plant tested negative.

No additional detections have been found at the Central Maui site after three rounds of late-November testing.

While there are still no confirmed measles cases on Maui or elsewhere in Hawaii, health officials have asked medical providers to remain alert.

The department is also urging residents to ensure they are up to date on the measles, mumps and rubella vaccine, noting that measles is highly contagious but preventable.

Infants under 1 year old are at greatest risk because they are too young to be routinely vaccinated, though early vaccination between 6 and 12 months may be recommended after exposure.

Measles typically starts with high fever, cough, runny nose and red eyes, followed by a rash that begins at the head and spreads downward. Complications can include pneumonia, neurological problems and death.

People with measles are contagious from four days before a rash appears through four days after. Anyone who believes they may have symptoms or may have been exposed should isolate immediately and contact a health care provider, the department said.