An outbreak of measles has hit Majuro, the capital of the Marshall Islands.
At least twenty one suspected cases have been treated at Majuro Hospital.
Russell Edwards, assistant secretary for primary health care, says the first case was seen late last week.
Although doctors at the hospital say they are in no doubt that the disease is measles, Mr Edwards says the Ministry of Health is waiting for official confirmation from a Honolulu laboratory.
If it is confirmed as measles, the ministry will mount a major vaccination campaign.
Until then, Mr Edwards says parents should make sure their children's measles vaccinations are up to date.
He says people who suspect they have measles should not come to the hospital, but be treated at home, as the disease is so contagious.