Health officials say 102 people in 14 states were reported to have measles in January, most of them stemming from "a large, ongoing multi-state outbreak linked to" Disneyland in California in mid-December.
The report comes a week after the Centers for Disease Control and Prevention issued an advisory to provide guidance for the nation's health care facilities and public health departments
The disease outbreak became apparent when visitors reported coming down with measles after visiting the park from December 15 to December 20.
Measles was declared eliminated in the United States in 2000, which means it is no longer native to the United States but continues to be brought in by international travelers.
Since 2001, the number of cases has topped 100 only five times, and there were more than 200 cases in 2011, the CDC says.
However, last year, the number spiked to 644 cases, the agency reported.
Measles is a highly communicable respiratory disease caused by a virus and spread through the air. Measles starts with a fever, runny nose, cough, red eyes and sore throat, the CDC says.