What position did Susan Monarez hold before being ousted shortly after her selection?

Susan Monarez served as the CDC director before being ousted shortly after her selection. The role of the CDC director is critical in public health, particularly in managing responses to health crises such as disease outbreaks. This position typically requires a strong adherence to scientific methods and public health practices, and changes in leadership can often occur in response to political pressures or shifting public health priorities.

The other roles listed, such as Department of Health Secretary, Health Policy Advisor, and Chief Epidemiologist, while related to public health, do not have the same level of direct oversight and impact on national health policy as the CDC director does. Thus, while those positions are important in their own right, they do not carry the same immediate weight or visibility in the context of Susan Monarez's situation and her subsequent removal from office.