Surveillance of transmitted HIV drug resistance among newly diagnosed, treatment-naive individuals at a county HIV clinic in Santa Clara County

Prevalence of HIV Transmitted Drug Resistance in Nanjing from 2018 to 2021

Background

Transmitted drug resistance (TDR) is a major challenge in the clinical management of acquired immunodeficiency syndrome (AIDS). Therefore, this study aimed to investigate the epidemic characteristics of and risk factors for human immunodeficiency virus (HIV)-1 TDR in Nanjing from 2018 to 2021 to provide support for clinical management.

Methods

The HIV-1 Pol gene was amplified by nested reverse transcription polymerase chain reaction from venous blood of 1190 HIV-infected patients who did not receive antiviral therapy, and the amplified product was sequenced using an in-house sequencing method. The sequencing result was compared with the HIV drug resistance database from Stanford University to elucidate the rates of antiviral drug resistance and distribution of drug-resistant mutation sites. Factors associated with TDR were evaluated using a logistic regression model.

Results

Detection of drug resistance at the gene level was successful in 1138 of 1190 HIV-1-infected patients (95.6%), and the overall 4-year drug resistance rate was 8.2% (93/1138). The drug resistance rate was higher for non-nucleoside reverse transcriptase inhibitors (NNRTIs; 6.7%) than for nucleoside reverse transcriptase inhibitors (NRTIs; 2.5%) or protease inhibitors (PIs; 0.1%) (χ ² = 83.907, P<0.0001). The most common NNRTI-related mutation was V179D/E followed by K103N. M184V was the dominant NRTI-associated mutation, and M46L/I was the most prevalent PI-associated mutation. A CD4⁺ T cell count of <50 cells/μL was significantly associated with an increased risk of TDR (OR=3.62, 95% CI: 1.38-9.51, P=0.009).

Conclusion

The prevalence of TDR in the city of Nanjing from 2018 to 2021 was at a moderate epidemic risk according to World Health Organization standards. Continuous monitoring of TDR can inform clinical diagnosis and treatment. Patients with advanced disease and a low CD4⁺ T lymphocyte count are more likely to have TDR in Nanjing.

Statewide Longitudinal Trends in Transmitted HIV-1 Drug Resistance in Rhode Island, USA

Background

HIV-1 transmitted drug resistance (TDR) remains a global challenge that can impact care, yet its comprehensive assessment is limited and heterogenous. We longitudinally characterized statewide TDR in Rhode Island.

Methods

Demographic and clinical data from treatment-naïve individuals were linked to protease, reverse transcriptase, and integrase sequences routinely obtained over 2004-2020. TDR extent, trends, impact on first-line regimens, and association with transmission networks were assessed using the Stanford Database, Mann-Kendall statistic, and phylogenetic tools.

Results

In 1123 individuals, TDR to any antiretroviral increased from 8% (2004) to 26% (2020), driven by non-nucleotide reverse transcriptase inhibitor (NNRTI; 5%-18%) and, to a lesser extent, nucleotide reverse transcriptase inhibitor (NRTI; 2%-8%) TDR. Dual- and triple-class TDR rates were low, and major integrase strand transfer inhibitor resistance was absent. Predicted intermediate to high resistance was in 77% of those with TDR, with differential suppression patterns. Among all individuals, 34% were in molecular clusters, some only with members with TDR who shared mutations. Among clustered individuals, people with TDR were more likely in small clusters.

Conclusions

In a unique (statewide) assessment over 2004-2020, TDR increased; this was primarily, but not solely, driven by NNRTIs, impacting antiretroviral regimens. Limited TDR to multiclass regimens and pre-exposure prophylaxis are encouraging; however, surveillance and its integration with molecular epidemiology should continue in order to potentially improve care and prevention interventions.

High prevalence of HIV-1 transmitted drug resistance and factors associated with time to virological failure and viral suppression in Taiwan

BACKGROUND

Integrase strand transfer inhibitor (InSTI)-based regimens have become the major first-line treatment for HIV-1-infected patients in Taiwan. Transmitted drug resistance (TDR) and several clinical characteristics are associated with time to virological failure or viral suppression; however, these have not been investigated in Taiwan.

OBJECTIVES

To determine the impact of several factors on treatment outcomes in HIV-1-infected patients in Taiwan.

METHODS

The cohort included 164 HIV-1 treatment-naive patients in Taiwan from 2018 to 2020. Blood specimens were collected to determine the genotypic drug resistance using the Stanford University HIV drug resistance database. Cox proportional hazards models were used to identify factors associated with time to virological failure or viral suppression.

RESULTS

The prevalence of TDR in Taiwan was 27.4% and an increasing trend was seen from 2018 to 2020. TDR mutations related to NNRTIs were the most prevalent (21%) while TDR to InSTIs remained at a relatively low level (1.3%). A baseline HIV-1 viral load of ≥100 000 copies/mL was associated with a shorter time to virological failure [multivariate hazard ratio (mHR) 7.84; P = 0.018] and longer time to viral suppression (mHR 0.46; P < 0.001). Time to viral suppression was shorter in patients receiving InSTI-based regimens (mHR 2.18; P = 0.006). Different InSTI-based regimens as initial treatment did not affect the treatment outcomes.

CONCLUSIONS

This study found an increasing trend of HIV-1 TDR prevalence from 2018 to 2020 in Taiwan. Baseline HIV-1 viral load and receiving InSTI-based regimens are important factors associated with time to virological failure or viral suppression.

Transmitted drug resistance among HIV-1 drug-naïve patients in Greece

OBJECTIVES

Despite the success of antiretroviral treatment (ART), the persisting transmitted drug resistance (TDR) and HIV genetic heterogeneity affect the efficacy of treatment. This study explored the prevalence of TDR among ART-naïve HIV patients in Greece during the period 2016-2019.

METHODS

Genotypic resistance testing was available for 438 ART-naïve HIV patients. Multivariable Poisson regression models were fitted.

RESULTS

The majority of patients were male, and there was a slight predominance of Hellenic (26.5%) over non-Hellenic (21.9%) nationality. The prevalence of TDR was 7.8%. There was a predominance of mutations for non-nucleoside reverse-transcriptase inhibitors (5.7%) over nucleoside reverse-transcriptase inhibitors (0.2%). No mutations to protease inhibitors were detected. The prevalence of resistance was 22.1% based on all mutations identified through the HIVdb interpretation system. The most frequent resistance sites were E138A (9.6%), K103N (6.4%), and K101E (2.1%). The majority of detected mutations were confined to subtype A (52.6%), followed by B (19.6%). Non-Hellenic nationality was significantly associated with an increased risk of TDR (relative risk 1.32, 95% confidence interval 1.04-1.69).

CONCLUSIONS

Non-B HIV infections predominate in Greece, with an increasing trend in recent years. The prevalence of TDR remains stable. Ongoing surveillance of resistance testing is needed to secure the long-term success of ART.