Characterization of Virologic-Immunologic Failure and Discordance among Newly Diagnosed HIV-Infected Adults in the Upper SouthernRegion of Thailand

Abstract

Virologic-immunologic failure and discordance are critical predictors of clinical outcomes in HIV-infected individuals. CD4+ T lymphocyte count (CD4) and HIV viral load are routinely used to monitor and assess responses to antiretroviral therapy (ART). This retrospective descriptive study aimed to examine the prevalence of virologic-immunologic failure and discordance, as well as to investigate associated factors, including sex, age, baseline CD4 count before ART initiation, clinical symptoms, ARV regimen modifications during treatment, occupation, marital status, pregnancy status, history of previous infections, opportunistic infections during ART, and viral load >1,000 copies/mL at least six months post-ART initiation among newly diagnosed HIV-infected adults in the upper southern region of Thailand. Participants received first-line ART for at least six months between 2021 and 2023. Data were analyzed using percentages, means, medians, chi-square tests, and odds ratios. Of the 492 participants, 68.3% were male and 31.7% were female, with a mean age of 37.3 years. The median baseline CD4 count before ART initiation was 250 cells/µL. Most participants received TDF+FTC+EFV (44.7%) or TLD (42.3%) as initial ART. Approximately 31.5% of participants were employed in general occupations, 54.9% were single, and 70.7% were asymptomatic at diagnosis. Among these, 23 experienced virologic failure, 41 had immunologic failure, 2 had both virologic and immunologic failure, 32 exhibited virologic discordance, and 21 showed immunologic discordance. Factors significantly associated with virologic failure included age 1,000 copies/mL at least six months post-ART initiation (OR 29.9). Baseline CD4 count 1,000 copies/mL after ART initiation had a markedly higher risk of virologic failure.