Herpes zoster as a missed opportunity for HIV diagnosis: a real-world analysis of testing practices

Herpes zoster (HZ) is a recognized HIV indicator condition, and international guidelines recommend routine HIV testing in such cases. We aimed to evaluate HIV testing rates, HIV positivity, missed diagnostic opportunities, and the HIV late diagnosis rate among adults diagnosed with HZ.

This retrospective cohort study included adult patients (≥ 18 years) diagnosed with HZ between January 2022 and December 2024, at a tertiary referral center. Patients with a prior diagnosis of HIV infection were excluded. The study recorded demographic and clinical characteristics, as well as HIV testing status. HIV positivity rates among patients who underwent HIV testing were evaluated, alongside the rate of subsequent HIV diagnoses in patients who were initially not tested.

A total of 2,446 patients with HZ were included. HIV testing was requested in 19.5% of patients at the time of HZ diagnosis. Among those tested, HIV positivity was 1.68%. Among patients not tested at baseline, 0.41% were subsequently diagnosed with HIV. The ARD between tested and non-tested groups was 1.26%. IPW analysis estimated an overall HIV prevalence of 1.78%, corresponding to approximately 44 expected cases; however, only 8 were diagnosed at initial presentation, indicating that a substantial proportion of HIV infections may not have been identified at the first clinical encounter.

Herpes zoster represents a significant missed opportunity for early HIV diagnosis. The low HIV testing rates and selective testing practices may contribute to late HIV diagnosis and missed opportunities for timely linkage to care. These findings support routine indicator condition-guided HIV testing to improve early detection and outcomes.