US media say massive layoffs have begun at public health organizations in the country. The dismissals are part of a push by President Donald Trump's administration to restructure the federal workforce.



The reports come amid an outbreak of measles in some US states, raising concerns that staff cutbacks could impede efforts to control the highly infectious disease.



The media outlets said on Tuesday the mass firing started at federal bodies, including the Department of Health and Human Services, the Centers for Disease Control and Prevention and the Food and Drug Administration.



Termination notices were reportedly sent out in emails in the early hours of the morning. Reports say some people showed up to work not realizing they had been dismissed.



Among those reported to have been pushed out of their positions are a senior official in charge of infectious disease prevention and a worker overseeing drug reviews. A senior tobacco regulator was also said to have lost his job.



Last month, Secretary of the HHS Department, Robert F. Kennedy Jr., announced that 20,000 jobs would be cut --about one quarter of the department's workforce.



Kennedy wrote on social media on Tuesday: "This overhaul is about realigning HSS with its core mission: to stop the chronic disease epidemic and Make America Healthy Again."



More than 480 cases of measles have been confirmed in 19 US states, mainly in Texas, since the beginning of the year. The layoffs have raised concerns about how the country will respond to health emergencies.