The strengthening of health systems is becoming increasingly recognized as necessary for the achievement of many objectives promoted or supported by global public health initiatives. Key within the effort to strengthen health systems is the development of a well-prepared, skilled, and knowledgeable public health workforce. Over 60 years ago, the United States Centers for Disease Control and Prevention (CDC) began the first training program in applied epidemiology, the Epidemic Intelligence Service (EIS), a two-year, in-service training program in epidemiology and public health practice. Since 1951, the EIS has produced welltrained and highly qualified applied or field epidemiologists, many of whom later became leaders within the US public health system. In 1980, the CDC began assisting other countries to develop their own field epidemiology training programs (FETPs), modeling them after the highly successful EIS program. FETPs differ from other training programs in epidemiology in that: (1) they are positioned within Ministries of Health and the activities of the residents are designed to address the priority health issues of the Ministry; (2) they stress the principle of training through service; and (3) they provide close supervision and mentoring by trained field epidemiologists. While FETPs are designed to be adaptable to the needs of any given country, there exist many fundamental similarities in the skills and knowledge required by public health workers. Recognizing this, CDC developed a standard core FETP curriculum that can be adapted to any country's needs. Countries can further customize FETP trainings to meet their specific needs by adding specialized "tracks" or by targeting different audiences and levels of the health system. Although FETPs require substantial investments in time and resources as well as 190Public Health Reviews, Vol. 33,No 1,[190][191][192][193][194][195][196][197][198][199][200][201][202][203] Applied Epidemiology Training Programs: CDC's Experience 191 significant commitment from ministries, CDC's vision is that every country will have access to an FETP to help build its public health workforce and strengthen its public health systems.

As of 2010 sub-Saharan Africa had approximately 865 million inhabitants living with numerous public health challenges. Several public health initiatives [e.g., the United States (US) President's Emergency Plan for AIDS Relief and the US President's Malaria Initiative] have been very successful at reducing mortality from priority diseases. A competently trained public health workforce that can operate multi-disease surveillance and response systems is necessary to build upon and sustain these successes and to address other public health problems. Sub-Saharan Africa appears to have weathered the recent global economic downturn remarkably well and its increasing middle class may soon demand stronger public health systems to protect communities. The Epidemic Intelligence Service (EIS) program of the US Centers for Disease Control and Prevention (CDC) has been the backbone of public health surveillance and response in the US during its 60 years of existence. EIS has been adapted internationally to create the Field Epidemiology Training Program (FETP) in several countries. In the 1990s CDC and the Rockefeller Foundation collaborated with the Uganda and Zimbabwe ministries of health and local universities to create 2-year Public Health Schools Without Walls (PHSWOWs) which were based on the FETP model. In 2004 the FETP model was further adapted to create the Field Epidemiology and Laboratory Training Program (FELTP) in Kenya to conduct joint competency-based training for field epidemiologists and public health laboratory scientists providing a master's degree to participants upon completion. The FELTP model has been implemented in several additional countries in sub-Saharan Africa. By the end of 2010 these 10 FELTPs and two PHSWOWs covered 613 million of the 865 million people in sub-Saharan Africa and had enrolled 743 public health professionals. We describe the process that we used to develop 10 FELTPs covering 15 countries in sub-Saharan Africa from 2004 to 2010 as a strategy to develop a locally trained public health workforce that can operate multi-disease surveillance and response systems.

Namibia faces a critical shortage of skilled public health workers to perform emergency response operations, preparedness activities and real-time surveillance. The Namibia Field Epidemiology and Laboratory Training Programme (NamFELTP) increases the number of skilled public health professionals and strengthens the public health system in Namibia. We describe the NamFELTP during its first 7 years, assess its impact on the public health workforce and provide recommendations to further strengthen the workforce. We reviewed disease outbreak investigations and response reports, field projects and epidemiological investigations conducted during 2012–2019. The data were analysed using descriptive methods such as frequencies and rates. Maps representing the geographical distribution of NamFELTP workforce were produced using QGIS software V.3.2. There were no formally trained field epidemiologists working in Namibia before the NamFELTP. In its 7 years of operation, the programme graduated 189 field epidemiologists, of which 28 have completed the Advanced FELTP. The graduates increased epidemiological capacity for surveillance and response in Namibia at the national and provincial levels, and enhanced epidemiologist-led outbreak responses on 35 occasions, including responses to outbreaks of human and zoonotic diseases. Trainees analysed data from 51 surveillance systems and completed 31 epidemiological studies. The NamFELTP improved outcomes in the Namibia’s public health systems; including functional and robust public health surveillance systems that timely and effectively respond to public health emergencies. However, the current epidemiological capacity is insufficient and there is a need to continue training and mentorship to fill key leadership and strategic roles in the public health system.