Health officials in California and Washington, facing outbreaks of measles this past spring, asked the Centers for Disease Control and Prevention in May to validate a test that can diagnose 500 cases in eight hours.

They did not hear back for two months. Officials from the West Coast Health Alliance — California, Washington, Oregon and Hawaii — recounted the experience this week in a letter to Dr. Erica Schwartz, the C.D.C.’s new director, who assumed the position in August, shortly after they got the agency’s reply. According to the letter, obtained by The New York Times, the C.D.C. had told them that it had “other competing priorities” and could not dedicate time to making a high-volume test available to state labs.