Enhancing indicator condition–guided HIV testing in Taiwan: a nationwide case–control study from 2009 to 2015

BACKGROUND: Although indicator condition (IC)-guided HIV testing (IC-HIVT) is effective at facilitating timely HIV diagnosis, research on IC categories and the related HIV risk in Taiwan is limited.

To improve the adoption and spread of IC-HIVT in Taiwan, this study compared the IC categories of people living with HIV (PLWH) and non-HIV controls and investigated delays in the diagnosis of HIV infection.

METHODS: This nationwide, retrospective, 1:10-matched case–control study analyzed data from the Notifiable Diseases Surveillance System and National Health Insurance Research Database to evaluate 42 ICs for the 5-year period preceding a matched HIV diagnostic date from 2009 to 2015.

The ICs were divided into category 1 ICs (AIDS-defining opportunistic illnesses [AOIs]), category 2 ICs (diseases associated with impaired immunity or malignancy but not AOIs), category 3 ICs (ICs associated with sexual behaviors), and category 4 ICs (mononucleosis or mononucleosis-like syndrome).

Logistic regression was used to evaluate the HIV risk associated with each IC category (at the overall and annual levels) before the index date.

Wilcoxon rank-sum test was performed to assess changes in diagnostic delays following an incident IC category by HIV transmission routes.

RESULTS: Fourteen thousand three hundred forty-seven PLWH were matched with 143,470 non-HIV controls.

The prevalence results for all ICs and category 1–4 ICs were, respectively, 42.59%, 11.16%, 15.68%, 26.48%, and 0.97% among PLWH and 8.73%, 1.05%, 4.53%, 3.69%, and 0.02% among non-HIV controls (all P < 0.001).

Each IC category posed a significantly higher risk of HIV infection overall and annually.

The median (interquartile range) potential delay in HIV diagnosis was 15 (7–44), 324.5 (36–947), 234 (13–976), and 74 (33–476) days for category 1–4 ICs, respectively.

Except for category 1 for men who have sex with men, these values remained stable across 2009–2015, regardless of the HIV transmission route.

CONCLUSIONS: Given the ongoing HIV diagnostic delay, IC-HIVT should be upgraded and adapted to each IC category to enhance early HIV diagnosis.

SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-024-18499-6.