Correction: Geographic and Temporal Trends in the Molecular Epidemiology and Genetic Mechanisms of Transmitted HIV-1 Drug Resistance: An Individual-Patient- and Sequence-Level Meta-Analysis

Enhancing public health programs with performance-based memorandum of understanding

This Viewpoint presents a case study that explored the effects of using a performance-based Memorandum of Understanding (MoU) in public health donor programs to enhance health metrics, program efficiency, and accountability. The MoU between Kebbi State Government in Nigeria and the United States Agency for International Development (USAID) focused on strengthening primary healthcare. It covered Health Systems Strengthening (HSS) indicators, overseen by an Operations Committee (OC) and a high-level Steering Committee (SC). Quarterly and biannual reviews tracked indicators through a dashboard developed by the Integrated Health Program (IHP). Results suggest that the MoU led to better monitoring of primary healthcare (PHC) revitalization, health sector work plan harmonization, and data quality. Dashboard tracking showed improved health facility financing, immunization, antenatal care, and skilled attendants at births. The use of the MoU demonstrated potential for boosting program efficiency, cost-effectiveness, and political commitment for resource mobilization in public health initiatives. Results support recommending MoUs as valuable tools for effective outcome-driven public health funding.

The Effect of Treatment-Associated Mutations on HIV Replication and Transmission Cycles

HIV/AIDS mortality has been decreasing over the last decade. While promising, this decrease correlated directly with increased use of antiretroviral drugs. As a natural consequence of its high mutation rate, treatments provide selection pressure that promotes the natural selection of escape mutants. Individuals may acquire drug-naive strains, or those that have already mutated due to treatment. Even within a host, mutation affects HIV tropism, where initial infection begins with R5-tropic virus, but the clinical transition to AIDS correlates with mutations that lead to an X4-tropic switch. Furthermore, the high mutation rate of HIV has spelled failure for all attempts at an effective vaccine. Pre-exposure drugs are currently the most effective drug-based preventatives, but their effectiveness is also threatened by viral mutation. From attachment and entry to assembly and release, the steps in the replication cycle are also discussed to describe the drug mechanisms and mutations that arise due to those drugs. Revealing the patterns of HIV-1 mutations, their effects, and the coordinated attempt to understand and control them will lead to effective use of current preventative measures and treatment options, as well as the development of new ones.

Low rate of pre-exposure prophylaxis and post-exposure prophylaxis uptake and high prevalence of transmitted drug resistance among newly diagnosed primary HIV infections in Shenzhen, China: a real-world retrospective study

BACKGROUND

Understanding the characteristics of newly diagnosed primary human deficiency virus-1 (HIV-1) infection in the context of the post-antiretroviral therapy era and HIV drug prophylaxis is essential for achieving the new target of 95-95-95-95 by 2025. This study reported the characteristics of newly diagnosed primary HIV-1 infection in Shenzhen.

METHODS

This is a real-world retrospective study. Eighty-seven newly diagnosed primary HIV-1-infected patients were recruited from January 2021 to March 2022 at the Third People's Hospital of Shenzhen. Demographic, epidemiological, diagnostic, drug resistance, and medical data were described and analyzed.

RESULTS

Overall, 96.6% (84/87) of the newly identified primary HIV-1-infected patients were male, including 88.5% (77/87) men have sex with men (MSM), with a median age of 29.0 years (Q1-Q3: 24.0-34.0 years); of these, 85.1% (74/87) reported high-risk sexual behaviors with casual partners. The rate of condom usage was only 28.7% (25/87). The overall rate of pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP) was 8.0% (7/87, including 4 PrEP and 3 PEP cases) around the potential exposure, although 41.4% of the patients had prior awareness of such interventions. Moreover, only 19.5% (17/87) had previously used PrEP or PEP. Of those, 58.8% (10/17) of the patients obtained drugs from the internet, and only 35.3% (6/17) reported good compliance. A total of 54.0% (47/87) of subjects were diagnosed by the HIV nucleic acid test. Acute retroviral syndrome appeared in 54.0% (47/87) of patients. The prevalence of transmitted drug resistance (TDR) mutation was 33.9% (19/56), including 6 (10.7%) against nucleoside reverse transcriptase inhibitor (NRTI) plus non-nucleoside reverse transcriptase inhibitor (NNRTI), 8 (14.3%) against NNRTI, and 5 (8.9%) against protease inhibitor (PI) only.

CONCLUSIONS

Owing to the low utilization rate and incorrect usage of PrEP and PEP, massive efforts are needed to promote HIV-preventive strategies in the MSM population. The extremely high prevalence of TDR mutation in this population implies the need for future pretreatment drug resistance surveillance.

Medicinal chemistry strategies for discovering antivirals effective against drug-resistant viruses

During the last forty years we have witnessed impressive advances in the field of antiviral drug discovery culminating with the introduction of therapies able to stop human immunodeficiency virus (HIV) replication, or cure hepatitis C virus infections in people suffering from liver disease. However, there are important viral diseases without effective treatments, and the emergence of drug resistance threatens the efficacy of successful therapies used today. In this review, we discuss strategies to discover antiviral compounds specifically designed to combat drug resistance. Currently, efforts in this field are focused on targeted proteins (e.g. multi-target drug design strategies), but also on drug conformation (either improving drug positioning in the binding pocket or introducing conformational constraints), in the introduction or exploitation of new binding sites, or in strengthening interaction forces through the introduction of multiple hydrogen bonds, covalent binding, halogen bonds, additional van der Waals forces or multivalent binding. Among the new developments, proteolysis targeting chimeras (PROTACs) have emerged as a valid approach taking advantage of intracellular mechanisms involving protein degradation by the ubiquitin-proteasome system. Finally, several molecules targeting host factors (e.g. human dihydroorotate dehydrogenase and DEAD-box polypeptide 3) have been identified as broad-spectrum antiviral compounds. Implementation of herein described medicinal chemistry strategies are expected to contribute to the discovery of new drugs effective against current and future threats due to emerging and re-emerging viral pandemics.

HIV-1 transmitted drug resistance surveillance: shifting trends in study design and prevalence estimates

INTRODUCTION

HIV-1 transmitted drug resistance (TDR) prevalence increased during the initial years of the antiretroviral therapy (ART) global scale-up. Few studies have examined recent trends in TDR prevalence using published genetic sequences and described the characteristics of ART-naïve persons from whom these published sequences have been obtained.

METHODS

We identified 125 studies published between 2014 and 2019 for which HIV-1 reverse transcriptase (RT) with or without protease from ≥50 ART-naïve adult persons were submitted to the GenBank sequence database. The population characteristics and TDR prevalence were compared to those in 122 studies published in the preceding five years between 2009 and 2013. TDR prevalence was analysed using median study-level and person-level data.

RESULTS AND DISCUSSION

The 2009 to 2013 and 2014 to 2019 studies reported sequence data from 32,866 and 41,724 ART-naïve persons respectively. Studies from the low- and middle-income country (LMIC) regions in sub-Saharan Africa, South/Southeast Asia and Latin America/Caribbean accounted for approximately two-thirds of the studies during each period. Between the two periods, the proportion of studies from sub-Saharan Africa and from South/Southeast Asia countries other than China decreased from 43% to 32% and the proportion of studies performed at sentinel sites for recent HIV-1 infection decreased from 33% to 22%. Between 2014 and 2019, median study-level TDR prevalence was 4.1% in South/Southeast Asia, 6.0% in sub-Saharan Africa, 9.1% in Latin America/Caribbean, 8.5% in Europe and 14.2% in North America. In the person-level analysis, there was an increase in overall, NNRTI and two-class NRTI/NNRTI resistance in sub-Saharan Africa; an increase in NNRTI resistance in Latin America/Caribbean, and an increase in overall, NNRTI and PI resistance in North America.

CONCLUSIONS

Overall, NNRTI and dual NRTI/NNRTI-associated TDR prevalence was significantly higher in sub-Saharan Africa studies published between 2014 and 2019 compared with those published between 2009 and 2013. The decreasing proportion of studies from the hardest hit LMIC regions and the shift away from sentinel sites for recent infection suggests that global TDR surveillance efforts and publication of findings require renewed emphasis.

Evaluation of HIV Transmission Clusters among Natives and Foreigners Living in Italy

We aimed at evaluating the characteristics of HIV-1 molecular transmission clusters (MTCs) among natives and migrants living in Italy, diagnosed between 1998 and 2018. Phylogenetic analyses were performed on HIV-1 polymerase (pol) sequences to characterise subtypes and identify MTCs, divided into small (SMTCs, 2–3 sequences), medium (MMTCs, 4–9 sequences) and large (LMTCs, ≥10 sequences). Among 3499 drug-naïve individuals enrolled in the Italian Cohort Naive Antiretroviral (ICONA) cohort (2804 natives; 695 migrants), 726 (20.8%; 644 natives, 82 migrants) were involved in 228 MTCs (6 LMTCs, 36 MMTCs, 186 SMTCs). Migrants contributed 14.4% to SMTCs, 7.6% to MMTCs and 7.1% to LMTCs, respectively. HIV-1 non-B subtypes were found in 51 MTCs; noteworthy was that non-B infections involved in MTCs were more commonly found in natives (n = 47) than in migrants (n = 4). Factors such as Italian origin, being men who have sex with men (MSM), younger age, more recent diagnosis and a higher CD4 count were significantly associated with MTCs. Our findings show that HIV-1 clustering transmission among newly diagnosed individuals living in Italy is prevalently driven by natives, mainly MSM, with a more recent diagnosis and frequently infected with HIV-1 non-B subtypes. These results can contribute to monitoring of the HIV epidemic and guiding the public health response to prevent new HIV infections.

Provincial and national prevalence estimates of transmitted HIV-1 drug resistance in South Africa measured using two WHO-recommended methods

BACKGROUND

Sentinel surveillance of transmitted HIV drug resistance (TDR) among recently infected populations within a country was recommended by the World Health Organization from 2004 to 2015.

METHODS

Serum specimens collected as part of the 2010, 2011 and 2012 National Antenatal Sentinel HIV Prevalence Surveys were used to estimate provincial and national TDR prevalence in South Africa.

RESULTS

Moderate (5-15%) levels of transmitted non-nucleoside reverse transcriptase inhibitor (NNRTI) drug class resistance were detected in three of five provinces surveyed in 2010 and 2011 (Eastern Cape, Free State and KwaZulu-Natal). Inclusion of all nine of South Africa's provinces in the 2012 survey enabled calculation of a national TDR point prevalence estimate: TDR to the NNRTI drug class was 5.4% (95% CI 3.7, 7.8%), with K103N and V106M being the most frequently detected mutations. TDR estimates for the nucleoside reverse transcriptase inhibitor (NRTI) drug class were 1.1% (95% CI 0.5, 2.4%) and 0.6% (95% CI 0.1, 1.6%) for protease inhibitors (PI).

CONCLUSIONS

These data provide national TDR estimates for South Africa in 2012 and indicate that levels of TDR were low to moderate for the NNRTI drug class and low for NRTIs and PIs in the population surveyed.

Defective Strand-Displacement DNA Synthesis Due to Accumulation of Thymidine Analogue Resistance Mutations in HIV-2 Reverse Transcriptase

Retroviral reverse transcriptases (RTs) have the ability to carry out strand displacement DNA synthesis in the absence of accessory proteins. Although studies with RTs and other DNA polymerases suggest that fingers subdomain residues participate in strand displacement, molecular determinants of this activity are still unknown. A mutant human immunodeficiency virus type 2 (HIV-2) RT (M41L/D67N/K70R/S215Y) with low strand displacement activity was identified after screening a panel of purified enzymes, including several antiretroviral drug-resistant HIV-1 and HIV-2 RTs. In HIV-1, resistance to zidovudine and other thymidine analogues is conferred by different combinations of M41L, D67N, K70R, L210W, T215F/Y, and K219E/Q (designated as thymidine analogue resistance-associated mutations (TAMs)). However, those changes are rarely selected in HIV-2. We show that the strand displacement activity of HIV-2_ROD mutants M41L/S215Y and D67N/K70R was only slightly reduced compared to the wild-type RT. In contrast, mutants D67N/K70R/S215Y and M41L/D67N/K70R/S215Y were the most defective RTs in reactions carried out with nicked and gapped substrates. Moreover, these enzymes showed the lowest nucleotide incorporation rates in assays carried out with strand displacement substrates. Unlike in HIV-2, substitutions M41L/T215Y and D67N/K70R/T215Y/K219Q had no effect on the strand displacement activity of HIV-1_BH10 RT. The strand displacement efficiencies of HIV-2_ROD RTs were consistent with the lower replication capacity of HIV-2 strains bearing the four major TAMs in their RT. Our results highlight the role of the fingers subdomain in strand displacement. These findings might be important for the development of strand-displacement defective RTs.

Curbing the rise of HIV drug resistance in low-income and middle-income countries: the role of dolutegravir-containing regimens

To improve virological suppression and address the emerging threat of HIV drug resistance, many low-income and middle-income countries are moving away from non-nucleoside reverse transcriptase inhibitors (NNRTI) and transitioning to dolutegravir as part of a more affordable and standardised antiretroviral therapy (ART). Although this transition could decrease the effect of rising NNRTI resistance and yield improved ART outcomes, it also presents new challenges. First, current safety concerns for dolutegravir use in women of childbearing potential require alternative solutions. Second, pre-existing resistance to the co-administered nucleoside reverse transcriptase inhibitors might reduce effectiveness and durability of dolutegravir, particularly if there is scarce access to viral load tests to monitor treatment outcomes. Third, there is inadequate information on the genetic correlates of resistance to dolutegravir, particularly in patients infected with HIV-1 non-B subtypes. Finally, clinical management of patients with confirmed virological failure on a dolutegravir-based regimen can pose challenges because of uncertainty around whether dolutegravir resistance has actually developed and switching is needed, or whether only interventions to improve adherence without switching are sufficient. These considerations should be addressed to consolidate expected gains from widespread introduction of dolutegravir in low-income and middle-income countries.

Transmission Dynamics of HIV-1 Drug Resistance among Treatment-Naïve Individuals in Greece: The Added Value of Molecular Epidemiology to Public Health

The presence of human immunodeficiency virus type 1 (HIV-1) drug resistance among drug-naïve patients remains stable, although the proportion of patients with virological failure to therapy is decreasing. The dynamics of transmitted resistance among drug-naïve patients remains largely unknown. The prevalence of non-nucleoside reverse transcriptase inhibitors (NNRTI) resistance was 16.9% among treatment-naïve individuals in Greece. We aimed to investigate the transmission dynamics and the effective reproductive number (R_e) of the locally transmitted NNRTI resistance. We analyzed sequences with dominant NNRTI resistance mutations (E138A and K103N) found within monophyletic clusters (local transmission networks (LTNs)) from patients in Greece. For the K103N LTN, the R_e was >1 between 2008 and the first half of 2013. For all E138A LTNs, the R_e was >1 between 1998 and 2015, except the most recent one (E138A_4), where the R_e was >1 between 2006 and 2011 and approximately equal to 1 thereafter. K103N and E138A_4 showed similar characteristics with a more recent origin, higher R_e during the first years of the sub-epidemics, and a declining trend in the number of transmissions during the last two years. In the remaining LTNs the epidemic was still expanding. Our study highlights the added value of molecular epidemiology to public health.

High Levels of Transmitted HIV Drug Resistance in a Study in Papua New Guinea

INTRODUCTION

Papua New Guinea is a Pacific Island nation of 7.3 million people with an estimated HIV prevalence of 0.8%. ART initiation and monitoring are guided by clinical staging and CD4 cell counts, when available. Little is known about levels of transmitted HIV drug resistance in recently infected individuals in Papua New Guinea.

METHODS

Surveillance of transmitted HIV drug resistance in a total of 123 individuals recently infected with HIV and aged less than 30 years was implemented in Port Moresby (n = 62) and Mount Hagen (n = 61) during the period May 2013-April 2014. HIV drug resistance testing was performed using dried blood spots. Transmitted HIV drug resistance was defined by the presence of one or more drug resistance mutations as defined by the World Health Organization surveillance drug resistance mutations list.

RESULTS

The prevalence of non-nucleoside reverse transcriptase inhibitor transmitted HIV drug resistance was 16.1% (95% CI 8.8%-27.4%) and 8.2% (95% CI 3.2%-18.2%) in Port Moresby and Mount Hagen, respectively. The prevalence of nucleoside reverse transcriptase inhibitor transmitted HIV drug resistance was 3.2% (95% CI 0.2%-11.7%) and 3.3% (95% CI 0.2%-11.8%) in Port Moresby and Mount Hagen, respectively. No protease inhibitor transmitted HIV drug resistance was observed.

CONCLUSIONS

The level of non-nucleoside reverse transcriptase inhibitor drug resistance in antiretroviral drug naïve individuals recently infected with HIV in Port Moresby is amongst the highest reported globally. This alarming level of transmitted HIV drug resistance in a young sexually active population threatens to limit the on-going effective use of NNRTIs as a component of first-line ART in Papua New Guinea. To support the choice of nationally recommended first-line antiretroviral therapy, representative surveillance of HIV drug resistance among antiretroviral therapy initiators in Papua New Guinea should be urgently implemented.

Frequency of transmitted drug resistance mutations among treatment-naïve HIV-1-infected individuals at a tertiary care centre in South India

INTRODUCTION

Morbidity and mortality among HIV-1-infected individuals has been dramatically reduced by the implementation of combinational antiretroviral therapy (ART). However, the efficiency of these therapies is compromised due to HIV-1 transmitted drug resistance mutations (TDRMs).

METHODS

We collected a total of 127 samples from ART-naïve HIV-infected individuals and sequenced the pol gene and analysed for drug resistance mutations using the Calibrated Population Resistance (CPR) tool in the Stanford database.

RESULTS

All the 127 clinical samples (100 %) were identified as HIV-1 subtype C. Based on the CPR tool, three strains (2.4 %) had TDRMs, and these were K101E, Y181C and G190A. Our findings correlated well with the WHO surveys conducted in Asia, including India, which consistently reported <5 % TDRM among the specific populations assessed.

CONCLUSION

In countries like India, regular monitoring of TDRMs will provide better information for clinical practice improvement and policy making.