The highly contagious delta variant of the coronavirus, which can cause more serious illness, has now been detected on Oahu, Maui, Kauai and Hawaii island, according to a Hawaii Department of Health press release.

“The rapid spread of the delta variant is troubling, but not surprising,” said State Laboratories Division Administrator Edward Desmond said in an email. “Cases of this particular strain of COVID-19 have doubled every two weeks in other jurisdictions so we expected it to move quickly after it was first detected on O‘ahu earlier this month.”

A total of 13 cases of the delta variant have been detected, including nine cases on Oahu, two on Maui, one on Kauai and one on Hawaii island.

“We believe the nine cases most recently identified represent seven or eight separate introductions into the state,” said acting State Epidemiologist Sarah Kemble said in an email. “Unfortunately, we can expect case numbers to grow. People who are not vaccinated face a greater risk than those protected by vaccines.”

Health officials are urging residents to get vaccinated as the delta variant can spread extremely quickly and is expected to become the dominant variant nationwide.

Information on where to get vaccinated can be found at hawaiicovid19.com/vaccine.