Costs of HIV Misdiagnoses: The Case for Retesting

The World Health Organization (WHO) urges immediate initiation of antiretroviral treatment (ART) for all persons who receive a HIV-positive diagnosis. A few instances remain however, in which false-positive diagnoses occur – when a person is not infected with HIV but receives a positive test result. Globally, studies report HIV misdiagnoses rates ranging from less than 1 percent to more than 10 percent, and there are significant social and financial costs for such misdiagnoses. In most cases, a second test to verify the initial diagnoses can eliminate or reduce the occurrence of HIV misdiagnoses and prevent unnecessary initiation of ART.

A new study published in the journal PLOS Medicine, co-authored by CDC scientists, estimates the costs and consequences of implementing retesting across African countries to verify an initial HIV-positive diagnosis. The modelling study estimates about 240,000 positive misdiagnoses may occur in Africa over 10 years, in the absence of retesting. According to Arielle Lasry, BBA MS PhD, the study’s lead author, “retesting for verification of HIV status when initiating treatment is less expensive than providing treatment to those with false HIV-positive diagnosis over an extended or lifetime use of ART.” Additional intangible costs of an HIV-positive diagnosis may include stigma and discrimination, violence, and psychological trauma. HIV-positive diagnosis may also influence partner, reproductive, and professional choices – those consequences only further the case for retesting for verification of HIV status.

From a public health perspective, HIV misdiagnoses can undermine the public’s trust in HIV test results, and in testing efforts generally. WHO recommends retesting all HIV-positive diagnoses for verification prior to initiating ART – though this recommendation is yet to be widely adopted. With support from the President’s Emergency Plan for AIDS Relief (PEPFAR), 3.2 million persons living with HIV were newly diagnosed in 2018 – CDC accounted for more than half of PEPFAR-supported new diagnoses within this period. The CDC sexually transmitted disease treatment guidelines – issued in 2015 – also recommends retesting to verify a preliminary HIV-positive test result.

For the African countries reviewed, estimated savings of $717 million can be achieved from 10 years of treatment costs avoided for the 180,000 true negative persons whose misdiagnosis is uncovered through retesting at time of ART initiation. The study urges the full implementation of WHO’s retesting recommendation as part of a comprehensive quality assurance program for HIV testing services. Doing so will increase the efficiency of the HIV testing programs, as well as the public’s trust in their countries’ public health system.