The head of the US Centres for Disease Control and Prevention (CDC) has resigned just months after taking the role.

Dr Brenda Fitzgerald is stepping down because she "owns certain complex financial interests", US Department of Health and Human Services spokesman Matt Lloyd said.

He said these interests "imposed a broad recusal limiting her ability to complete all of her duties as the CDC director.

"Due to the nature of these financial interests, Dr Fitzgerald could not divest from them in a definitive time period", he said.

He said after advising US Health Secretary Alex Azar of both the status of the financial interests and the scope of her recusal, Dr Fitzgerald tendered, and the secretary accepted, her resignation.

The Associated Press reports that when Dr Fitzgerald took the job, she owned a range of stocks - including holdings in beer and soda companies, a tobacco company and a number of health care firms.

Dr Fitzgerald was appointed as the 17th director of the CDC on July 7th, 2017.

She had previously served as the commissioner of the Georgia Department of Public Health (DPH) and state health officer from 2011 to 2017.

Dr Fitzgerald, a board-certified obstetrician-gynecologist, has practiced medicine for three decades.

The CDC is the US health protection agency and is part of the Department of Health and Human Services.