Maine health officials say the number of reported cases of chickenpox at a shelter for asylum seekers is in the single digits.
The Maine Center for Disease Control and Prevention has said individuals staying at Portland Expo are considered exposed to the disease. The agency added late Saturday that the number of cases being investigated is limited.
The Expo is a basketball arena being used to house asylum seekers while they seek permanent housing. They face an Aug. 15 deadline to leave the facility.
The Maine CDC and city officials say they're working together to halt the disease's spread. The city has been asking volunteers who visited the Expo on July 26 or later to watch for symptoms and check vaccination records.
The disease is best prevented with a vaccine.