Samoa's Ministry of the Prime Minister and Cabinet said 153 new measles cases have been recorded in the past 24 hours, bringing the total to 1797.
About 92 percent of the 147 people being treated at health facilities are children, with 11 critically ill children in intensive care.
One couple have lost three of their five children.
The majority of the infected are on Upolu island.
The ministry said a mass vaccination campaign was launched on Wednesday and more than 10,128 people have since been immunised.