State officials have confirmed a second case of measles on Oahu linked to the first one earlier this month.

The state Department of Health said the second Oahu resident with measles is a close contact of the first confirmed case announced April 10. That first case was confirmed in an unvaccinated Oahu resident upon his return from international travel.

Contact tracing is underway, according to DOH Immunization Program Branch Chief Ronald Balajadia, and officials are reaching out to all people who may have been exposed to this second case.

A medical advisory was also issued Monday, asking health care providers to identify, isolate and report suspected measles cases.

“The department is always concerned any time any measles case is presented to us,” said Balajadia. “The disease is not endemic, meaning it doesn’t exist within our community. It actually has to be brought into our community, so that is always going to be a high, high concern.”

DOH declined to provide the age or gender of the second person at this time due to the ongoing investigation and privacy. Balajadia said it remains unknown whether the second person had been vaccinated against measles.

Both people with measles, however, are doing fine and in recovery.

Since lab results confirmed the second measles case Friday, staff have been working diligently to find all contacts to inform them of possible exposure and to educate them about the disease and what to do should symptoms appear.

Measles is a highly contagious virus that can spread to others through coughing and sneezing, according to the Centers for Disease Control and Prevention. It can cause serious illness, especially among babies and young children.

Symptoms usually start with a high fever, cough, runny nose and red, watery eyes, followed by a rash of tiny red spots. Initial symptoms may be similar to COVID-19 or the flu but usually present at the same time as a fever, Balajadia said, followed by the telltale sign of the rash three to five days later.

What’s important to know is that infected people can spread measles from four days before through four days after a rash appears.

So masking and distancing is important for those who are exhibiting symptoms.

“Masking is very important; just to try to minimize exposure to anybody,” said Balajadia. “It could be the flu, COVID or any other disease. We want to try to minimize any respiratory spread.”

Measles can be prevented with a measles, mumps and rubella vaccine, which is currently required to attend public school in Hawaii unless religious exemptions are filed.

Most people receive their first dose of the MMR vaccine at their one-year, well-child visit, followed by the second one between ages 4 to 6. But MMR vaccination rates have dropped among children globally and nationally since pre-pandemic years, according to the Health Department.

The coverage rate for school-age children in the state is at about 90%, according to Balajadia.

Any adults who are unsure of whether they have been vaccinated against measles should contact their health care provider, he said, especially if travel is planned.

CDC recommends being fully vaccinated against measles at least two weeks before departure for international travel. One dose of MMR vaccine provides 93% protection, said the CDC, while two doses provide 97% protection.

Measles outbreaks are also on the rise globally, including in American Samoa — which recently declared a public health emergency.

According to the American Samoa Department of Health, there has been one lab-confirmed case and 31 suspected or probable cases, including in children under 6 months of age who are hospitalized.

The two cases in Hawaii, DOH said, are not related to any cases in American Samoa.

“Right now we’re hearing more cases throughout,” said Balajadia, “so we want to make sure we protect our community from succumbing to this particular disease.”

The last major measles outbreak in the state was in 2014, with 15 cases detected on three different isles. These cases, so far, have been limited to Oahu.