Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom; Influenza Division, Centers for Disease Control and Prevention, Atlanta, United States; Influenza Program, Centers for Disease Control and Prevention-South Africa, Pretoria, South Africa; Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Services, Johannesburg, South Africa; Department of Science and Technology/National Research Foundation:Vaccine-Preventable Diseases, University of the Witwatersrand, Johannesburg, South Africa; Department of Medicine, Pietermaritzburg Metropolitan Hospital Complex and University of KwaZulu Natal, South Africa; MRC/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, Johannesburg, South Africa; CTS Global, Inc., Los Angeles, United States; Zoonoses Research Unit, Department of Medical Virology, University of Pretoria, Pretoria, South Africa; Schools of Public Health and Pathology, University of the Witwatersrand, Johannesburg, South Africa
Budgell, E., Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom, Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Services, Johannesburg, South Africa; Cohen, A.L., Influenza Division, Centers for Disease Control and Prevention, Atlanta, United States, Influenza Program, Centers for Disease Control and Prevention-South Africa, Pretoria, South Africa; McAnerney, J., Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Services, Johannesburg, South Africa; Walaza, S., Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Services, Johannesburg, South Africa; Madhi, S.A., Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Services, Johannesburg, South Africa, Department of Science and Technology/National Research Foundation:Vaccine-Preventable Diseases, University of the Witwatersrand, Johannesburg, South Africa; Blumberg, L., Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Services, Johannesburg, South Africa; Dawood, H., Department of Medicine, Pietermaritzburg Metropolitan Hospital Complex and University of KwaZulu Natal, South Africa; Kahn, K., MRC/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, Johannesburg, South Africa; Tempia, S., Influenza Division, Centers for Disease Control and Prevention, Atlanta, United States, Influenza Program, Centers for Disease Control and Prevention-South Africa, Pretoria, South Africa, CTS Global, Inc., Los Angeles, United States; Venter, M., Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Services, Johannesburg, South Africa, Zoonoses Research Unit, Department of Medical Virology, University of Pretoria, Pretoria, South Africa; Cohen, C., Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Services, Johannesburg, South Africa, Schools of Public Health and Pathology, University of the Witwatersrand, Johannesburg, South Africa
Background: The World Health Organisation recommends outpatient influenza-like illness (ILI) and inpatient severe acute respiratory illness (SARI) surveillance. We evaluated two influenza surveillance systems in South Africa: one for ILI and another for SARI. Methodology: The Viral Watch (VW) programme has collected virological influenza surveillance data voluntarily from patients with ILI since 1984 in private and public clinics in all 9 South African provinces. The SARI surveillance programme has collected epidemiological and virological influenza surveillance data since 2009 in public hospitals in 4 provinces by dedicated personnel. We compared nine surveillance system attributes from 2009-2012. Results: We analysed data from 18,293 SARI patients and 9,104 ILI patients. The annual proportion of samples testing positive for influenza was higher for VW (mean 41%) than SARI (mean 8%) and generally exceeded the seasonal threshold from May to September (VW: weeks 21-40; SARI: weeks 23-39). Data quality was a major strength of SARI (most data completion measures >90%; adherence to definitions: 88-89%) and a relative weakness of the VW programme (62% of forms complete, with limited epidemiologic data collected; adherence to definitions: 65-82%). Timeliness was a relative strength of both systems (e.g. both collected >93% of all respiratory specimens within 7 days of symptom onset). ILI surveillance was more nationally representative, financially sustainable and expandable than the SARI system. Though the SARI programme is not nationally representative, the high quality and detail of SARI data collection sheds light on the local burden and epidemiology of severe influenza-associated disease. Conclusions: To best monitor influenza in South Africa, we propose that both ILI and SARI should be under surveillance. Improving ILI surveillance will require better quality and more systematic data collection, and SARI surveillance should be expanded to be more nationally representative, even if this requires scaling back on information gathered. © 2015, Public Library of Science. All rights reserved.