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High percentage of undiagnosed HIV cases within a hyperendemic South African community: a population-based study
  1. Alain Vandormael1,2,3,
  2. Tulio de Oliveira3,4,
  3. Frank Tanser1,2,4,5,
  4. Till Bärnighausen1,5,6,7,
  5. Joshua T Herbeck8
  1. 1 Africa Health Research Institute (AHRI), Durban, South Africa
  2. 2 School of Nursing and Public Health, University of KwaZulu-Natal, Durban, South Africa
  3. 3 KwaZulu-Natal Research Innovation and Sequencing Platform (KRISP), University of KwaZulu-Natal, South Africa
  4. 4 Centre for the AIDS Programme of Research in South Africa (CAPRISA), Durban, South Africa
  5. 5 Department of Infection and Population Health, Institute of Epidemiology and Health Care, University College London, London, UK
  6. 6 Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Massachusetts, USA
  7. 7 Heidelberg Institute for Public Health, University of Heidelberg, Heidelberg, Germany
  8. 8 International Clinical Research Center, Department of Global Health, University of Washington, Seattle, Washington, USA
  1. Correspondence to Dr Alain Vandormael, School of Nursing and Public Health, University of KwaZulu-Natal, Durban 4001, South Africa; avandormael{at}


Background Undiagnosed HIV infections could undermine efforts to reverse the global AIDS epidemic by 2030. In this study, we estimated the percentage of HIV-positive persons who remain undiagnosed within a hyperendemic South African community.

Methods The data come from a population-based surveillance system located in the Umkhanyakude district of the northern KwaZulu-Natal province, South Africa. We annually tested 38 661 adults for HIV between 2005 and 2016. Using the HIV-positive test results of 12 039 (31%) participants, we then back-calculated the incidence of infection and derived the number of undiagnosed cases from this result.

Results The percentage of undiagnosed HIV cases decreased from 29.3% in 2005 to 15.8% in 2011. During this period, however, approximately 50% of the participants refused to test for HIV, which lengthened the average time from infection to diagnosis. Consequently, the percentage of undiagnosed HIV cases reversed direction and steadily increased from 16.1% to 18.9% over the 2012–2016 period.

Conclusions Results from this hyperendemic South African setting show that the HIV testing rate is low, with long infection times, and an unsatisfactorily high percentage of undiagnosed cases. A high level of repeat HIV testing is needed to minimise the time from infection to diagnosis if the global AIDS epidemic is to be reversed within the next two decades.

  • HIV
  • undiagnosed
  • testing
  • test-and-treat
  • South Africa

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  • Contributors AV undertook the statistical analysis and wrote the manuscript. AV and JTH conceived the study. JTH supervised the study, with additional advice, feedback and comments provided by FT, TdO and TB.

  • Funding This work was supported by a South African Medical Research Council (SA MRC) Flagship grant (MRC-RFA-UFSP-01-2013/UKZN HIVEPI). Funding for the Africa Health Research Institute’s Demographic Surveillance Information System and Population-based HIV Survey was received from the Wellcome Trust. FT was supported by two National Institute of Health (NIH) grants (R01HD084233 and R01AI124389) as well as a UK Academy of Medical Sciences Newton Advanced Fellowship (NA150161). JTH was supported by two NIH grants (R01AI108490 and R01AI127232). TB was supported by the Alexander von Humboldt Foundation through the endowed Alexander von Humboldt Professorship funded by the German Federal Ministry of Education and Research, as well as by the Wellcome Trust, the European Commission, the Clinton Health Access Initiative, and by four NIH grants (R01-HD084233, R01-AI124389, D43-TW009775, R01-AI112339).

  • Competing interests None declared.

  • Patient consent Obtained.

  • Ethics approval Ethics approval for data collection and use was obtained from the biomedical and ethics committee of the University of KwaZulu-Natal (Durban, South Africa).

  • Provenance and peer review Not commissioned; externally peer reviewed.