The state Department of Health has confirmed four additional measles cases on Maui and Kauai, bringing the total number of confirmed cases to seven.

Last week the DOH reported the initial three cases: one on Maui and two on Kauai, with each involving unvaccinated young adults who recently traveled either to the Philippines or Indonesia and Malaysia.

Two of the four new cases — one on Kauai and another on Maui — are related to the initial cases reported on Kauai.

In a news release issued Thursday, state epidemiologist Dr. Sarah Park said, "We are very concerned. These additional cases are an example of how contagious this disease is and how quickly it can spread."

Staffers are working closely with health care providers and facilities as well as the Center for Disease Control and Prevention’s Honolulu Quarantine Station to identify those who may have been exposed and to make sure they are being treated and monitored, Park said.

Measles is highly contagious. Ninety percent of people who are not immune to it will contract the disease from an infected person. Symptoms generally begin about 14 days after a person is infected.

The Health Department said the best way to prevent measles is to get vaccinated.

For more information, go to health.hawaii.gov/docd/home/imm.