Two scientists from the Centers for Disease Control and Prevention are in American Samoa to survey whether the territory is free from the painful and disfiguring disease lymphatic filariasis.
Alongside Department of Health, the CDC team has been visiting schools to take blood samples from each student.
In 2011, tests showed that less than one percent of children were positive for filariasis, down from 16.5 percent in 1999.
A CDC Health Scientist Kimberly Won says about 400 students have already taken the survey, and the CDC team is hoping to reach more than 1,000 students by the end of the week.
"I think we will continue to probably do a little bit of follow up work and surveys as part of the surveillance, just to make sure. But after this survey, American Samoa has met all of the requirements that are given by WHO."