The performance of different case definitions for severe influenza surveillance among HIV-infected and HIV-uninfected children aged <5 years in South Africa, 2011-2015.

In 2014, the World Health Organization (WHO) proposed a new severe influenza surveillance case definition, which has not been evaluated in a high human immunodeficiency virus (HIV) prevalence setting. Our study aimed to assess the performance of this proposed case definition in identifying influenza among HIV-uninfected and HIV-infected children aged <5 years in South Africa. We prospectively enrolled children aged <5 years hospitalised with physician-diagnosed lower respiratory tract infection (LRTI) at two surveillance sites from January 2011 to December 2015. Epidemiologic and clinical data were collected. We tested nasopharyngeal aspirates for influenza using reverse transcription polymerase chain reaction. We used logistic regression to assess factors associated with influenza positivity among HIV-infected and HIV-uninfected children. We calculated sensitivity and specificity for different signs and symptoms and combinations of these for laboratory-confirmed influenza. We enrolled 2,582 children <5 years of age with LRTI of whom 87% (2,257) had influenza and HIV results, of these 14% (318) were HIV-infected. The influenza detection rate was 5% (104/1,939) in HIV-uninfected and 5% (16/318) in HIV-infected children. Children with measured fever (≥38°C) were two times more likely to test positive for influenza than those without measured fever among the HIV-uninfected (OR 2.2, 95% Confidence Interval (CI) 1.5-3.4; p<0.001). No significant association was observed between fever and influenza infection among HIV-infected children. Cough alone had sensitivity of 95% (95% CI 89-98%) in HIV-uninfected and of 100% (95% CI 79-100%) in HIV-infected children but low specificity: 7% (95% CI 6-8%) and 6% (95% CI 3-9%) in HIV-uninfected and HIV-infected children, respectively. The WHO post-2014 case definition for severe acute respiratory illness (SARI-an acute respiratory infection with history of fever or measured fever of ≥ 38°C and cough; with onset within the last ten days and requires hospitalization), had a sensitivity of 66% (95% CI 56-76%) and specificity of 46% (95% CI 44-48%) among HIV-uninfected and a sensitivity of 63% (95% CI 35-84%) and a specificity of 42% (95% CI 36-48%) among HIV-infected children. The sensitivity and specificity of the WHO post-2014 case definition for SARI were similar among HIV-uninfected and HIV-infected children. Our findings support the adoption of the 2014 WHO case definition for children aged <5 years irrespective of HIV infection status.

South Africa field epidemiology training program: developing and building applied epidemiology capacity, 2007-2016.

In 2007, South Africa (SA) launched a field epidemiology training program (SAFETP) to enhance its capacity to prevent, detect, and respond to public health threats through training in field epidemiology. The SAFETP began as a collaboration between the SA National Department of Health (NDOH), National Institute for Communicable Diseases (NICD), and the University of Pretoria (UP), with technical and financial support from the U.S. Centers for Disease Control and Prevention (CDC). In 2010, the CDC in collaboration with the NICD, established a Global Disease Detection (GDD) Center in SA, and the SAFETP became a core activity of the GDD center. Similar to other FETPs globally, the SAFETP is a 2-year, competency-based, applied epidemiology training program, following an apprenticeship model of 'learn by doing'. SAFETP residents spend approximately 25% of the training in classroom-based didactic learning activities, and 75% in field activities to attain core competencies in epidemiology, biostatistics, outbreak investigation, scientific communication, surveillance evaluation, teaching others, and public health leadership. Residents earn a Master's in Public Health (MPH) degree from UP upon successfully completing a planned research study that serves as a mini-dissertation.Since 2007, SAFETP has enrolled an average of 10 residents each year and, in 2017, enrolled its 11th cohort. During the first 10 years of the program, 98 residents have been enrolled, 89% completed the 2-year program, and of these, 76 (87%) earned an MPH degree. Of those completing the program, 88% are employed in the public health sector, and work at NICD, NDOH, Provincial Health Departments, foreign health institutions, or non-governmental organizations. In the first 10 years of the program, the combined outputs of trainees included over 130 outbreak investigations, more than 150 abstracts presented at national and international scientific conferences, more than 80 surveillance system evaluations, and more than 45 manuscripts published in peer-reviewed scientific journals. The SAFETP is having an impact in building epidemiology capacity for public health in South Africa. Developing methods to directly link and measure the impact of the program is planned for the future.