[14][15] From October 1997– January 1999 shortly after his graduation, Ihekweazu completed his Housemanship and served the mandatory one-year Nigerian National Youth Service Corps Scheme.

He applied his skills and experience in field epidemiology across a wide range of public health challenges, mostly during outbreaks of infectious diseases.

During his time there he managed the South East of England's Regional Epidemiology Unit (REU) including a team of 13 Public Health specialists.

The REU provided outbreak investigation and management, surveillance, advice, and specialist support for the control of communicable diseases, as well as leading the response to environmental hazards in the South East Region of England, a population of about 10 million people.

[21] In 2011, Ihekweazu moved to Johannesburg, South Africa to become the co-director of the Centre for Tuberculosis at the National Institute for Communicable Diseases with primary responsibility for the epidemiology section.

His mandate included designing the service, recruiting the leadership provincial epidemiologists, initiating a supportive relationship in the nine provinces of South Africa, developing epidemiology capacity and surveillance for the institute.

[23] In February 2014, Ihekweazu became a part-time senior adviser at the National Institute for Communicable Diseases (NICD), Johannesburg, South Africa.

Following the signing of its Act by President Muhammadu Buhari, Nigeria Centre for Disease Control (NCDC) became an independent agency on 13 November 2018.

[26] In addition, Ihekweazu oversaw the establishment of the National Reference Laboratory in Abuja, establishment of national and sub-national Public Health Emergency Operations Centres[27] expansion of the agency's field epidemiology training program to build the capacity of public health professionals across the country amongst other achievements.

The Hub works closely with Member States, WHO Regional and Country Offices, regional and national health agencies, academia, private sector and other non-state actors across geographies and disciplines to collaborate and co-create tools to gather and analyse data to better prepare for, detect and respond to health emergencies.

The Bill for an Act to establish NCDC was finally passed by the National Assembly and signed into law by President Muhammadu Buhari in November 2018.