Characterising HIV-Indicator conditions among two nationwide long-term cohorts of people living with HIV in Germany (1999-2023).

Background/objective: Information about occurrence and affected groups of symptoms/diagnoses indicative of an HIV infection (so-called HIV indicator conditions; HIV-ICs) is lacking. We analyse HIV-IC incidence, transmission risks and immune status among people living with HIV (PLWH) antiretroviral therapy (ART) naive.

Methods: Diagnoses reported for ART-naive PLWH from two multicentre observational, prospective cohort studies between 1999-2023 were analysed. Incidence rates per 1,000 person-years (PYs) were calculated for the overall study period and time periods defined by ART treatment recommendations. For further description, CD4 counts around HIV-IC diagnosis (+ -30 days) and HIV-transmission routes were collected.

Results: In total 15,940 diagnoses of 18,534 PLWH in Germany were included. Of those 81% were male (median age: 36 years) and 56% reported being men, who have sex with men as the likely HIV-transmission route. Incidence rates varied between the different HIV-ICs. Syphilis had the highest incidence rate (34 per 1,000 PYs; 95% confidence interval [CI] 29-40) for sexually transmitted infections (STIs), hepatitis B was highest for viral hepatitis diagnoses (18 per 1,000 PYs; 95% CI 17-20); according to CDC-classification herpes zoster for HIV-associated diagnoses (22 per 1,000; 95% CI 20-24) and candidiasis for AIDS-defining diagnoses (30 per 1,000 PYs; 95% CI 29-32). Most PLWH with HIV-ICs (hepatitis, HIV-associated diagnoses and AIDS-defining conditions) had CD4 cell counts < 350.

Conclusion: This analysis characterizes HIV-ICs regarding the incidence, HIV-transmission route and patients' immune status. The results underline the importance of HIV-IC-based screening to detect PLWH with already partially impaired immune status and in need of timely ART initiation.