Virological outcome and patterns of HIV-1 drug resistance in patients with 36 months' antiretroviral therapy experience in Cameroon

HIV-1 subtype diversity and immuno-virological outcomes among adolescents failing antiretroviral therapy in Cameroon: A cohort study

OBJECTIVE

We sought to evaluate the variability of HIV-1 and its effect on immuno-virological response among adolescents living with perinatally acquired HIV (APHI).

METHODS

A cohort study was conducted from 2018-2020 among 311 APHI receiving antiretroviral therapy (ART) in Cameroon. Sequencing of protease and reverse transcriptase regions was performed for participants experiencing virological failure, VF, (Plasma viral load, PVL ≥ 1000 RNA copies/ml). HIV-1 subtypes were inferred by phylogeny; immuno-virological responses were monitored at 3-time points (T1-T3). Cox regression modeling was used to estimate adjusted hazard ratios (aHRs) of progression to: CD4 < 250, and PVL > 5log10, adjusted for acquired drug resistance, gender, ART line, adherence, and duration on treatment; p < 0.05 was considered statistically significant.

RESULTS

Of the 141 participants in VF enrolled, the male-female ratio was 1:1; mean age was 15 (±3) years; and median [IQR] duration on ART was 51 [46-60] months. In all phases, 17 viral clades were found with a predominant CRF02_AG (58.2%, 59.4%, and 58.3%). From T1-T3 respectively, there was an increasing CD4 count (213 [154-313], 366 [309-469], and 438 [364-569] cells/mm3) and decline log10 PVL (5.23, 4.43, and 4.43), similar across subtypes. Among participants with CRF02_AG infection, duration of treatment was significantly associated with both rates of progression to CD4 < 250, and PVL > 5log10, aHR = 0.02 (0.001-0.52), and aHR = 0.05 (0.01-0.47) respectively. Moreover, four potential new HIV-1 recombinants were identified (CRF02_AG/02D, CRF02_AG/02A1F2, D/CRF02_AG, and AF2/CRF02_AG), indicating a wide viral diversity.

CONCLUSION

Among APHI in settings like Cameroon, there is a wide genetic diversity of HIV-1, driven by CRF02_AG and with potential novel clades due to ongoing recombination events. Duration of treatment significantly reduces the risk of disease progression.

High rate of virological failure and HIV drug resistance in semi-rural Gabon and implications for dolutegravir-based regimen efficacy

BACKGROUND

The projected UNAIDS goal of ending AIDS by 2030 requires significant global efforts to improve current and future ART strategies. In this study, we assessed viral load (VL) suppression and acquired drug resistance, as well as future efficacy of dolutegravir-based combinations for patients living in semi-rural regions of Gabon.

METHODS

Eligible study participants were adults receiving ART and recruited between 2018 and 2019 in Franceville, Gabon. VL testing was conducted to assess VL suppression and HIV drug resistance (HIVDR) testing was performed to identify resistance mutations and assess their impact on ongoing and future ART regimens.

RESULTS

We recruited 219 participants overall. The median time on ART was 27 months and 216/219 participants were on first-line ART. VL suppression (VL < 1000 copies/mL) was 57.1% (95% CI 50.5-63.8) overall; 59.4% (51.4-67.5) and 52.2% (40.3-64.2) for women and men, respectively. The overall prevalence of HIVDR was 21.9% among the study population and 67.2% among those who failed ART. Presence of both NRTI and NNRTI mutations was found in 84.6% of sequences with drug resistance mutations, and full activity of a dolutegravir-based first-line regimen including tenofovir disoproxil fumarate/lamivudine/dolutegravir was expected only for 5/39 patients with a resistant virus.

CONCLUSIONS

This study shows a very low rate of VL suppression in a semi-rural context in Africa. Moreover, the high burden of HIVDR has affected both current and newly recommended ART strategies. Better management of ART in resource-limited settings is still a challenging ambition.

High HIV-1 Virological Failure and Drug Resistance among Adult Patients Receiving First-Line ART for At least 12 Months at a Decentralized Urban HIV Clinic Setting in Senegal before the Test-and-Treat

BACKGROUND

The feasibility of antiretroviral therapy (ART) monitoring remains problematic in decentralized HIV clinic settings of sub-Saharan Africa. We assessed the rates and correlates of HIV-1 virological failure (VF) and drug resistance (DR) in 2 pre-test-and-treat urban clinic settings of Senegal.

METHODS

Consenting HIV-1-infected adults (⩾18 years) receiving first-line ART for ⩾12 months were cross-sectionally enrolled between January and March 2015, at the referral outpatient treatment center of Dakar (n = 151) and decentralized regional hospital of Saint-Louis (n = 127). In the 12 months preceding plasma specimens' collection patients at Saint-Louis had no viral load (VL) testing. Significant predictors of VF (VL ⩾ 1000 copies/ml) and DR (clinically relevant mutations) were determined using binomial logistic regression in R software.

RESULTS

Of the 278 adults on EFV-/NVP-based regimens, 32 (11.5% [95%CI: 8.0-15.9]) experienced VF. Failing and non-failing patients had comparable median time [interquartile] on ART (69.5 [23.0-89.5] vs 64.0 [34.0-99.0] months; P = .46, Mann-Whitney U-test). Of the 27 viraemic isolates successfully genotyped, 20 (74.1%) carried DR mutations; most frequent were M184VI (55.6%), K103N (37.1%), thymidine analog mutations (29.6%), Y181CY (22.2%). The pattern of mutations did not always correspond to the ongoing treatment. The adjusted odds of VF was significantly associated with the decentralized clinic site (P < .001) and CD4 < 350 cells/mm3 (P < .006). Strong correlates of DR also included Saint-Louis (P < .009), CD4 < 350 cells/mm3 (P <. 001), and nevirapine-based therapies (comparator: efavirenz-based therapies; P < .027). In stratification analyses by site, higher rate of VF at Saint-Louis (20.5% [95%CI: 13.8-28.5] vs 4.0% [95%CI: 1.5-8.5] in Dakar) was associated with nevirapine-based therapies (OR = 3.34 [1.07-11.75], P = .038), self-reported missing doses (OR = 3.30 [1.13-10.24], P = .029), and medical appointments (OR = 2.91 [1.05-8.47], P = .039) in the last 1 and 12 months(s), respectively. The higher rate of DR at Saint-Louis (12.9% [95%CI: 7.6-20.1] vs 2.7% [95%CI: 0.7-6.7] in Dakar) was associated with nevirapine-based therapies (OR = 5.13 [1.12-37.35], P = .035).

CONCLUSION

At decentralized urban settings, there is need for enhanced virological monitoring and adherence support. HIV programs in Senegal should intensify early HIV diagnosis for effective test-and-treat. These interventions, in addition to the superiority of efavirenz-based therapies provide a favorable framework for transitioning to the recommended potent drug dolutegravir, thereby ensuring its long-term use.

Genetic diversity and antiretroviral resistance-associated mutation profile of treated and naive HIV-1 infected patients from the Northwest and Southwest regions of Cameroon

BACKGROUND

Antiretroviral therapy (ART) has improved the survival of HIV infected persons. However, rapid scale-up of ART and the high HIV-1 genetic variability, has greatly influenced the emergence of drug-resistant strains. This constitutes a potential threat to achieving the UNAIDS' 90-90-90 goals by 2020. We investigated the prevalent HIV-1 genotypes, drug resistance-associated mutations and assessed some predictors of the occurrence of these mutations.

METHODS

This was a hospital-based cross-sectional study conducted between October 2010 and June 2012. Participants were consecutively enrolled from selected HIV treatment centers of the Southwest and Northwest regions of Cameroon. Viral load was determined with the automated Abbott Real-time HIV-1 m2000rt System. HIV genotyping and antiretroviral resistance mutations analysis were performed using Bayer's HIV-1 TRUGENE™ Genotyping Kit and OpenGene DNA Sequencing system. The drug resistance mutation was interpreted with the Stanford HIV database. Epidemiological data were obtained using pre-tested semi-structured questionnaires.

RESULTS

Of the 387 participants, 239 were successfully genotyped. The median age of these participants was 33 years (interquartile range, IQR: 28-40 years), and a majority (65.7%) were female. A total of 29.3% of the participants were receiving ART. The median duration of ART was 10.5 months (IQR: 4-17.25 months). The median CD4 count and log10 viral load of study participants were 353.5 cells/ml (IQR:145-471) and 4.89 copies/ml (IQR: 3.91-5.55) respectively. CRF02 (A/G) (69%) was the most prevalent subtype followed by G (8.2%) and F (6.7%). Overall, resistance mutations were present in 37.1% of ART-experienced and 10.7% of ART-naive patients. Nucleoside reverse transcriptase inhibitors (NRTI) mutations occurred in 30% of ART-experienced and 2.4% of ART-naïve patients, while non-nucleoside reverse transcriptase inhibitors (NNRTI) mutations occurred in 34.2% of ART-experienced and 10.1% of -naïve patients. M184V (8.4%, 20/239) and K103N (5.4%, 13/239) were the most prevalent mutations. Major protease inhibitor mutations occurred in 3 (1.3%) out of the 239 sequences. The duration of ART independently predicted the occurrence of resistance mutation among ART-experienced patients.

CONCLUSION

The high resistance to NNRTIs, which are the main support to the backbone (NRTIs) first-line antiretroviral regimen in Cameroon, has prompted the need to rollout an integrase strand transfer inhibitor regimen (containing Dolutegravir) with a higher genetic barrier to resistance as the preferred first line regimen.

HIV-1 drug resistance testing is essential for heavily-treated patients switching from first- to second-line regimens in resource-limited settings: evidence from routine clinical practice in Cameroon

Background

With the phase-out of stavudine (d4T), change to first-line regimens with zidovudine (AZT) or tenofovir (TDF) in resource-limited settings (RLS) might increase risks of cross-resistance to nucleos(t) ide reverse transcriptase inhibitors (NRTI). This would restrict the scope of switching to the World Health Organisation (WHO)-recommended standard second-line combinations (SLC) without HIV drug resistance (HIVDR)-testing in routine clinical practice.

Methods

An observational study was conducted among 101 Cameroonian patients (55.4% male, median [IQR] age 34 [10–41] years) failing first-line antiretroviral therapy (ART) in 2016, and stratified into three groups according to NRTIs exposure: exposure to both thymidine analogues AZT “and” D4T (group-A, n = 55); exposure to both TDF and AZT “or” D4T (group-B, n = 22); exposure solely to D4T (group-C, n = 24). Protease-reverse transcriptase HIVDR was interpreted using the HIVdb penalty scores (≥60: high-resistance; 20–59: intermediate-resistance; < 20: susceptible). The acceptable threshold for potential-efficacy was set at 80%.

Results

The median [IQR] CD4, viral RNA, and time on ART, were respectively 129 [29–466] cells/μl, 71,630 [19,041-368,000] copies/ml, and 4 [2–5] years. Overall HIVDR-level was 89.11% (90/101), with 83.2% harbouring M184 V (high-level 3TC/FTC-resistance) and only 1.98% (2/101) major HIVDR-mutations to ritonavir-boosted protease-inhibitors (PI/r). Thymidine-analogue mutations (TAMs)-1 [T215FY (46.53%), M41 L (22.77%), L210 W (8.91%)], with cross-resistance to AZT and TDF, were higher compared to TAMs-2 [D67N (21.78%), K70R (19.80%), K219QE (18.81%)]. As expected, K65R was related with TDF-exposure: 0% (0/55) in group-A, 22.72% (5/22) group-B, 4.17% (1/24) group-C (p = 0.0013). The potential-efficacy of AZT vs. TDF was respectively 43.64% (24/55) vs. 70.91% (39/55) in group-A (p = 0.0038); 63.64% (14/22) vs. 68.28% (15/22) in group-B (p = 1.0000); and 37.50% (9/24) vs. 83.33% (20/24) in group-C (p = 0.0032). CRF02_AG was the prevailing subtype (63.40%), followed by CRF11.cpx (8.91%), A₁ (7.92%), G (5.94%); without any significant effect of the subtype-distribution on HIVDR (92.2% in CRF02_AG vs. 83.8% in non-AG; p = 0.204).

Conclusion

First-line ART-failure exhibits high-level NRTI-resistance, with potential lower-efficacy of AZT compared to TDF. Significantly, using our 80% efficacy-threshold, only patients without NRTI-substitution on first-line could effectively switch to SLC following the WHO-approach. Patients with multiple NRTI-substitutions (exposed to both thymidine-analogues and TDF) on first-line ART would require HIVDR-testing to select active NRTIs for SLC.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-3871-0) contains supplementary material, which is available to authorized users.

Heterogeneity of virological suppression in the national antiretroviral programme of Cameroon (ANRS 12288 EVOLCAM)

OBJECTIVES

In terms of HIV infection, western and central Africa is the second most affected region world-wide, and the gap between the regional figures for the testing and treatment cascade and the Joint United Nations Programme on HIV/AIDS (UNAIDS) 90-90-90 targets is particularly worrying. We assessed the prevalence of virological suppression in patients routinely treated in 19 hospitals in Cameroon.

METHODS

A cross-sectional survey was performed in adult patients receiving antiretroviral therapy (ART) in the Centre and Littoral regions. The prevalences of virological suppression (<1000 HIV-1 RNA copies/mL) were compared among all 19 hospitals using the χ² test. Potential individual and health care-related determinants of virological suppression were assessed using multivariate logistic regression models.

RESULTS

A total of 1700 patients (74% women; median age 41 years; median time on ART 3.7 years) were included in the study. The prevalence of virological suppression was 82.4% overall (95% confidence interval 80.5-84.2%). It ranged from 57.1 to 97.4% according to the individual hospital (P < 0.001). After adjustment, virological suppression was associated with age, CD4 cell count at ART initiation, disclosure of HIV status to family members, interruption of ART for more than two consecutive days, and location of patient's residence and hospital (rural/urban). These factors did not explain the heterogeneity of virological suppression between the study hospitals (P < 0.001).

CONCLUSIONS

The overall prevalence of virological suppression was reassuring. Nevertheless, the heterogeneity of virological suppression among hospitals highlights that, in addition to programme-level data, health facility-level data are crucial in order to tailor the national AIDS programme's interventions with a view to achieving the third UNAIDS 90 target.

Nationwide Estimates of Viral Load Suppression and Acquired HIV Drug Resistance in Cameroon

BACKGROUND

Population-based studies to estimate viral load (VL) suppression and rate of acquired HIV drug resistance (ADR) are essential in sub-Saharan Africa. We conducted the first nationally representative study estimating VL suppression and ADR in Cameroon.

METHODS

Eligible participants were patients on antiretroviral therapy (ART) for 12 to 24 months (ART 12-24) or 48 to 60 months (ART 48-60). ART 12-24 participants were recruited from 24 randomly selected clinics in both urban and rural regions. ART 48-60 participants were recruited from 7 urban clinics. Recruitment occurred from February to August 2015. Dried blood spots (DBSs) and plasma specimens were collected and tested for HIV-1 RNA level and presence of drug resistance mutations (DRM) when VL ≥ 1000 copies/ml.

RESULTS

Overall, 1064 ART 12-24 and 388 ART 48-60 participants were recruited. Viral suppression in the ART 12-24 group was 72.1% (95% CI: 66.3-77.2) overall, 75.0% (65.2-82.7) in urban sites, and 67.7% (58.3-75.8) in rural sites. In the ART 48-60 group, viral suppression was 67.7% (55.8-77.7). Overall, HIV drug resistance (HIVDR) was 17.7% (15.1-20.6) and 28.3% (17.4-42.5) in the ART 12-24 and ART 48-60 groups, respectively. However, among patients with VL ≥ 1000 copies/ml, HIVDR was identified in 63.3% (52.0-73.3) of ART 12-24 patients, and in 87.7% (67.4-96.1) of ART 48-60 patients.

CONCLUSIONS

Results of this first nationwide study indicate alarming levels of virological failure and ADR in Cameroon. Better ART management is urgently needed and should focus on improving ART adherence, availability of VL monitoring, and more timely switches to second-line ART.

Viral load testing and the use of test results for clinical decision making for HIV treatment in Cameroon: An insight into the clinic-laboratory interface

Background

The viral load (VL) in patients receiving antiretroviral therapy (ART) is the best predictor of treatment outcome. The anticipated benefits of VL monitoring depend on the actual uptake of VL test results for clinical decisions. The objective of this study was to assess the uptake and utilization of VL test results for clinical decisions on HIV treatment in Cameroon, from 2013 to 2017.

Methods

This was a retrospective cohort analysis of data from files of patients receiving ART at Buea, Limbe, Bamenda and Bafoussam regional hospital HIV treatment centers. A simple random pick of six file blocks was performed in each shelf that corresponded to a year of initiation, and the contents of all selected files were reviewed and the information needed for the study entered a structured questionnaire. The data collected was recorded in Epi Info (version 7.1.5.2), and analyzed using SATA (version 12.1; StataCorp LP).

Results

Eight hundred and thirty files were reviewed. The mean duration on ART was 39.4±12 months. Viral load testing uptake was 24.33% and only one VL test had been done by all patients. Approximately 65% of the patients did the first VL after more than 24 months on ART. The median turnaround (TAT) time for VL testing was 6 days (Interquartile range (IQR) 3-7days). Among 201 patients who did a VL test, 94.55% had VL suppression (≤1000copies/mm³). Approximately 54% of the patients with virologic failure were switched to a second-line regimen.

Conclusions

The uptake of viral load testing is low in North West, South West and West Regions of Cameroon. The current TAT for VL testing is plausible. The rate of switch to second line regimen is low. It is time to strengthen the scale up of VL testing and improve the rate of switch to second-line regimen in Cameroon.

Patterns of emergent resistance-associated mutations after initiation of non-nucleoside reverse-transcriptase inhibitor-containing antiretroviral regimens in Taiwan: a multicenter cohort study

Background

Increasing trends of resistance-associated mutations (RAMs) to non-nucleoside reverse-transcriptase inhibitors (nNRTIs) have raised concerns about the effectiveness of the regimens in the national HIV treatment programs in resource-limited countries. We aimed to retrospectively investigate the incidence and patterns of emergent RAMs of HIV-1 in HIV-positive adults experiencing virological failure to first-line nNRTI-containing combination antiretroviral therapy (cART) in Taiwan.

Patients and methods

Between June 2012 and March 2016, 1138 antiretroviral-naïve HIV-positive adults without baseline RAMs who initiated nNRTI-containing regimens were included for analysis. Virological failure was defined as plasma viral load (PVL) ≥200 copies/mL after 6 months of cART or confirmed PVL ≥200 copies/mL after achieving PVL <50 copies/mL. Population sequencing was retrospectively performed to detect baseline and emergent RAMs. RAMs were interpreted using the International AIDS Society-USA 2016 mutations list.

Results

Seventy-one patients (6.2%) developed virological failure, which occurred in 14.8% (43/291), 3.9% (26/675), and 1.2% (2/172) of patients receiving 2 nucleoside reverse-transcriptase inhibitors (NRTIs) plus nevirapine, efavirenz, and rilpivirine, respectively. Among those, 53 (74.6%) had emergent RAMs identified, which included 43 (81.1%), 53 (100.0%), and 1 (1.9%) with RAMs to NRTIs, nNRTIs, and protease inhibitors, respectively; and 43 (81.1%) had multi-drug resistance. The most common emergent RAMs to NRTIs were M184V/I (42.3%) and K65R (28.2%), and those to nNRTIs were Y181C (42.3%), K103N (15.5%), G190A/E/Q (12.7%), V179D/E (12.7%), and V108I (9.9%).

Conclusion

While the rates of virological failure varied with the nNRTI used, the rate of emergent RAMs of HIV-1 to NRTIs and nNRTIs among the antiretroviral-naïve patients who failed nNRTI-containing cART remained low.

Observed HIV drug resistance associated mutations amongst naïve immunocompetent children in Yaoundé, Cameroon

Introduction

The emergence of drug resistance mutations (DRMs) has been a major threat for successful lifelong combination antiretroviral therapy (cART), especially for HIV-vertically infected children within the context of the prevention of mother-to-child transmission (PMTCT). This study aimed to evaluate DRMs amongst immune competent treatment-naïve children in Cameroon.

Methods

A cross-sectional study was conducted between 2015 and 2016 amongst 55 proxy consented HIV-1 positive children, aged 9 months to 6 years. They were all immune competent, cART naïve and with unknown history of PMTCT. CD4 cell counts and genotypic drug resistance testing were performed using standard methods.

Results

Levels of DRMs to protease (PR) inhibitors (PIs), nucleoside reverse transcriptase inhibitors (NRTIs) and non-NRTIs were 27.6%, 3.7% and 40.7%, respectively. Only minor DRMs were observed for PR. The observed mutations for NRTI were K65R, T215I and K219E (33.0% each) and for NNRTI: V106M, Y181C and Y188H (6.0% each). Only minor accessory mutations were found in the integrase (IN) region.

Conclusion

Despite widely available cART we still observe naïve HIV children, especially from the rural communities. We observe that a proportion of study participants had HIV-1 drug resistance associated mutations (RAMs). Data generated could help strengthen the current PMTCT programmes within the country. There is a need to upscale approaches for drug resistance testing for children in Cameroon and many other resource-limited settings.

Virological response, HIV-1 drug resistance mutations and genetic diversity among patients on first-line antiretroviral therapy in N'Djamena, Chad: findings from a cross-sectional study

Background

The national antiretroviral therapy in the Republic of Chad provides free of charge antiretroviral regimens and therapeutic monitoring for patients receiving antiretroviral therapy nationwide. For a successful programmatic uptake, these efforts merit to be supported by thorough assessments of antiretroviral therapy response and HIV-1 drug resistance surveillance, especially with risks of cross-resistance due to the gradual stavudine phasing out in such national settings. We therefore evaluated the virological response to antiretroviral therapy, HIV-1 drug resistance emergence and circulating HIV-1 clades in a Chad context. A cross-sectional and prospective study was conducted among 116 patients (41 [δ ± 6.87] years, 59% female) receiving first-line antiretroviral therapy for ≥ 6 months in Ndjamena, Chad, in 2011–2012, enrolled consecutively. To ensure accuracy, plasma viral load was concomitantly measured using Abbott Real-Time and Cobas AmpliPrep/TaqMan (v2.0), and virological failure defined as ≥ 1000 HIV-1 RNA copies/ml. Plasma from patients experiencing virological failure were processed for sequencing of HIV-1 protease-reverse transcriptase using the ANRS-AC.11 resistance testing protocol; drug resistant mutations were interpreted using the ANRS-AC11 algorithm; and phylogenetic analysis was performed using MEGA.v.6.

Results

Majority of patients was receiving zidovudine plus lamivudine plus nevirapine (46%), stavudine plus lamivudine plus nevirapine (41%) and tenofovir plus emtricitabine plus efavirenz (11%), for a median time-on-treatment of 5 [IQR 4–7] years. The rate of virological failure was 43% (50/116), with 86% (43/50) sequencing performance. Overall, 32% (37/116) patients presented ≥ one major drug resistant mutation(s), with 29% (34/116) to nucleos(t)ide reverse transcriptase inhibitors (67% [29/43] M184V/I, 30% [13/43] T215Y/F, 19% [8/43] V75A/F/I/L/M, 9% [4/43] K70P/R/W, 9% [4/43] K219E/N/Q and 5% [2/43] A62V); 86% (37/43) to non-nulceos(t)ide reverse transcriptase inhibitors (30% [13/43] K103N/S/E, 26% [11/43] Y181C/V/F/L, 2% [1/43] L100I, 2% [1/43] F227L, 2% [1/43] P225H); and 2% (1/43) to protease inhibitors (M46I, I54V, V82S). Six HIV-1 subtypes were found: 30% circulating recombinant form (CRF02_AG), 30% J, 16% G, 9% A, 9% D, 5% F.

Conclusions

In Chad, almost half of patients are failing first-line antiretroviral therapy after 5 years, with considerable drug resistant mutations at failure. Absence of K65R supports the use of tenofovir-containing regimens as preferred first-line and as suitable drug for second-line combinations, in this setting with significant HIV-1 genetic diversity.

Electronic supplementary material

The online version of this article (10.1186/s13104-017-2893-1) contains supplementary material, which is available to authorized users.

High level of HIV-1 drug resistance mutations in patients with unsuppressed viral loads in rural northern South Africa

Background

Combination antiretroviral therapy (cART) has significantly reduced HIV morbidity and mortality in both developed and developing countries. However, the sustainability of cART may be compromised by the emergence of viral drug resistance mutations (DRM) and the cellular persistence of proviruses carrying these DRM. This is potentially a more serious problem in resource limited settings.

Methods

DRM were evaluated in individuals with unsuppressed viral loads after first or multiple lines of cART at two sites in rural Limpopo, South Africa. Seventy-two patients with viral loads of >1000 copies/ml were recruited between March 2014 and December 2015. Complete protease (PR) and partial Reverse Transcriptase (RT) sequences were amplified from both plasma RNA and paired proviral DNA from 35 of these subjects. Amplicons were directly sequenced to determine subtype and DRM using the Stanford HIV Drug Resistance Interpretation algorithm.

Results

Among the 72 samples, 69 could be PCR amplified from RNA and 35 from both RNA and DNA. Sixty-five (94.2%) viruses were subtype C, while one was subtype B (1.4%), one recombinant K/C, one recombinant C/B and one unclassified. Fifty-eight (84%) sequences carried at least one DRM, while 11 (15.9%) displayed no DRM. DRM prevalence according to drug class was: NRTI 60.8% NNRTI 65.2%, and PI 5.8%. The most common DRMs were; M184V (51.7%), K103N (50%), V106M (20.6%), D67N (13.3%), K65R (12%). The frequency of the DRM tracked well with the frequency of use of medications to which the mutations were predicted to confer resistance. Interestingly, a significant number of subjects showed predicted resistance to the newer NNRTIs, etravirine (33%) and rilpivirine (42%), both of which are not yet available in this setting. The proportion of DRM in RNA and DNA were mostly similar with the exception of the thymidine analogue mutations (TAMs) D67N, K70R, K219QE; and K103N which were slightly more prevalent in DNA than RNA. Subjects who had received cART for at least 5 years were more likely to harbour >2 DRM (p < 0.05) compared to those treated for a shorter period. DRM were more prevalent in this rural setting compared to a neighbouring urban setting.

Conclusion

We found a very high prevalence of NRTI and NNRTI DRM in patients from rural Limpopo settings with different durations of treatment. The prevalence was significantly higher than those reported in urban settings in South Africa. The dominance of NNRTI based mutations late in treatment supports the use of PI based regimens for second line treatment in this setting. The slight dominance of TAMs in DNA from infected PBMCs compared to plasma virus requires further studies that should include cART subjects with suppressed virus. Such studies will improve our understanding of the pattern of drug resistance and dynamics of viral persistence in these rural settings.

Multimethod Longitudinal HIV Drug Resistance Analysis in Antiretroviral-Therapy-Naive Patients

The global intensification of antiretroviral therapy (ART) can lead to increased rates of HIV drug resistance (HIVDR) mutations in treated and also in ART-naive patients. ART-naive HIV-1-infected patients from Cameroon were subjected to a multimethod HIVDR analysis using amplification-refractory mutation system (ARMS)-PCR, Sanger sequencing, and longitudinal next-generation sequencing (NGS) to determine their profiles for the mutations K103N, Y181C, K65R, M184V, and T215F/Y. We processed 66 ART-naive HIV-1-positive patients with highly diverse subtypes that underlined the predominance of CRF02_AG and the increasing rate of F2 and other recombinant forms in Cameroon. We compared three resistance testing methods for 5 major mutation sites. Using Sanger sequencing, the overall prevalence of HIVDR mutations was 7.6% (5/66) and included all studied mutations except K65R. Comparing ARMS-PCR with Sanger sequencing as a reference, we obtained a sensitivity of 100% (5/5) and a specificity of 95% (58/61), caused by three false-positive calls with ARMS-PCR. For 32/66 samples, we obtained NGS data and we observed two additional mismatches made up of minority variants (7% and 18%) that might not be clinically relevant. Longitudinal NGS analyses revealed changes in HIVDR mutations in all five positive subjects that could not be attributed to treatment. In one of these cases, superinfection led to the temporary masking of a resistant virus. HIVDR mutations can be sensitively detected by ARMS-PCR and sequencing methods with comparable performances. Longitudinal changes in HIVDR mutations have to be considered even in the absence of treatment.

Virological success after 12 and 24 months of antiretroviral therapy in sub-Saharan Africa: Comparing results of trials, cohorts and cross-sectional studies using a systematic review and meta-analysis

BACKGROUND

UNAIDS recently defined the 90-90-90 target as a way to end the HIV epidemic. However, the proportion of virological success following antiretroviral therapy (ART) may not be as high as the anticipated 90%, and may in fact be highly heterogeneous. We aimed to describe the proportion of virological success in sub-Saharan Africa and to identify factors associated with the proportion of virological success.

METHODS

We performed a systematic review and meta-analysis focusing on the proportion of patients in sub-Saharan Africa who demonstrate virological success at 12 and 24 months since ART initiation, as well as at 6 and 36 months, where possible. Programme factors associated with the proportion of virological success were identified using meta-regression. Analyses were conducted using both on-treatment (OT) and intention-to-treat (ITT) approaches.

RESULTS

Eighty-five articles were included in the meta-analysis, corresponding to 125 independent study populations. Using an on-treatment approach, the proportions (95% confidence interval (CI)) of virological success at 12 (n = 64) and at 24 (n = 32) months since ART initiation were 87.7% (81.3-91.0) and 83.7% (79.8-87.6), respectively. Univariate analysis indicated that the proportion of virological success was not different by study design. Multivariate analysis at 24 months showed that the proportion of virological success was significantly larger in studies conducted in public sector sites than in other sites (p = 0.045). Using an ITT approach, the proportions (95% CI) of virological success at 12 (n = 50) and at 24 (n = 20) months were 65.4% (61.8-69.1) and 56.8% (51.3-62.4), respectively. At 12 months, multivariate analysis showed that the proportion of success was significantly lower in cohort studies than in trials (63.0% vs. 71.1%; p = 0.017). At 24 months, univariate analysis demonstrated that the proportion of success was also lower in cohorts.

DISCUSSION

Regardless of the time following ART initiation, and of the threshold, proportions of virological success were highly variable. Evidence from this review suggests that the new international target of 90% of patients controlled is not yet being achieved, and that in order to improve the virological outcome, efforts should be made to improve retention in care.

Virologic Failure and Human Immunodeficiency Virus Drug Resistance in Rural Cameroon With Regard to the UNAIDS 90-90-90 Treatment Targets

Background.

In rural Africa, data on virologic effectiveness of antiretroviral treatment (ART) are not sufficient to assess the gap with the UNAIDS 90-90-90 treatment targets. We investigated the prevalences of unsuppressed viral load and antiretroviral drug resistance and the profile of genotypic resistance mutations among patients routinely treated in rural Cameroon.

Methods.

A cross-sectional study was performed in 2013–2014 among patients ≥15 years and on first-line ART for ≥6 months in a district hospital. Patients were offered free access to human immunodeficiency virus viral load testing. Genotypic drug resistance testing was done when the viral load was >1000 copies/mL. Multivariate logistic regression models were used to assess the relationship of unsuppressed viral load or antiretroviral drug resistance with sociodemographic and medical characteristics.

Results.

Of 407 patients (women 74.9%, median age 41.8 years, median time on ART 29.2 months), 96 (23.6%; 95% confidence interval [CI], 19.5–28.0) had unsuppressed viral load and 74 (18.2%; 95% CI, 14.6–22.3) had antiretroviral drug resistance. The prevalences of unsuppressed viral load and resistance increased with time on ART, from 12.0% and 8.0% in the 6- to 12-month group to 31.3% and 27.1% in the >72-month group, respectively. All 74 patients with antiretroviral drug resistance were resistant to nonnucleoside reverse-transcriptase inhibitors, and 57 of them were also resistant to nucleoside reverse-transcriptase inhibitors.

Conclusions.

Our estimations were among the highest observed in the west and central African region. The proportion of patients with virologic failure should be divided at least by 2 to reach the UNAIDS 90-90-90 treatment targets.

HIV Drug Resistance and Phylogeny Profile in Naïve and Antiretroviral-Experienced Patients in Tehran, Iran

BACKGROUND

Increasing the accessibility of antiretroviral therapy (ART) has caused the emergence of drug resistance in patients receiving ART and in naïve patients. The aim of this study was to evaluate HIV subtype and drug resistance between naïve patients and ART-experienced patients.

METHODS

Blood samples were collected from 78 antiretroviral and naïve HIV-1 patients; antiretroviral-resistant mutations and subtyping were then determined by sequencing pol regions.

RESULTS

Phylogenetic analysis revealed that 96.1% of sequences belong to the CRF35-AD subtype. Transmitted drug resistance was determined in 14% of drug-naïve patients and 40% of ART-experienced patients.

CONCLUSION

The findings of this study illustrated the importance of resistance testing before and during ART treatment. This study can be used to set up a best medicine strategy in Iranian guidelines.

Predictors of poor retention on antiretroviral therapy as a major HIV drug resistance early warning indicator in Cameroon: results from a nationwide systematic random sampling

Background

Retention on lifelong antiretroviral therapy (ART) is essential in sustaining treatment success while preventing HIV drug resistance (HIVDR), especially in resource-limited settings (RLS). In an era of rising numbers of patients on ART, mastering patients in care is becoming more strategic for programmatic interventions. Due to lapses and uncertainty with the current WHO sampling approach in Cameroon, we thus aimed to ascertain the national performance of, and determinants in, retention on ART at 12 months.

Methods

Using a systematic random sampling, a survey was conducted in the ten regions (56 sites) of Cameroon, within the “reporting period” of October 2013–November 2014, enrolling 5005 eligible adults and children. Performance in retention on ART at 12 months was interpreted following the definition of HIVDR early warning indicator: excellent (>85%), fair (85–75%), poor (<75); and factors with p-value < 0.01 were considered statistically significant.

Results

Majority (74.4%) of patients were in urban settings, and 50.9% were managed in reference treatment centres. Nationwide, retention on ART at 12 months was 60.4% (2023/3349); only six sites and one region achieved acceptable performances. Retention performance varied in reference treatment centres (54.2%) vs. management units (66.8%), p < 0.0001; male (57.1%) vs. women (62.0%), p = 0.007; and with WHO clinical stage I (63.3%) vs. other stages (55.6%), p = 0.007; but neither for age (adults [60.3%] vs. children [58.8%], p = 0.730) nor for immune status (CD4_351–500 [65.9%] vs. other CD4-staging [59.86%], p = 0.077).

Conclusions

Poor retention in care, within 12 months of ART initiation, urges active search for lost-to-follow-up targeting preferentially male and symptomatic patients, especially within reference ART clinics. Such sampling strategy could be further strengthened for informed ART monitoring and HIVDR prevention perspectives.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1991-3) contains supplementary material, which is available to authorized users.

In-depth analysis of HIV-1 drug resistance mutations in HIV-infected individuals failing first-line regimens in West and Central Africa

OBJECTIVE

In resource-limited countries, antiretroviral therapy (ART) has been scaled up, but individual monitoring is still suboptimal. Here, we studied whether or not ART had an impact on the frequency and selection of drug resistance mutations (DRMs) under these settings. We also examined whether differences exist between HIV-1 genetic variants.

DESIGN

A total of 3736 sequences from individuals failing standard first-line ART (n = 1599, zidovudine/stavudine + lamivudine + neviparine/efavirenz) were analyzed and compared with sequences from reverse transcriptase inhibitor (RTI)-naive individuals (n = 2137) from 10 West and Central African countries.

METHODS

Fisher exact tests and corrections for multiple comparisons were used to assess the significance of associations.

RESULTS

All RTI-DRM from the 2015 International Antiviral Society list, except F227C, and nine mutations from other expert lists were observed to confer extensive resistance and cross-resistance. Five additional independently selected mutations (I94L, L109I, V111L, T139R and T165L) were statistically associated with treatment. The proportion of sequences with multiple mutations and the frequency of all thymidine analog mutations, M184V, certain NNRTIS, I94L and L109I showed substantial increase with time on ART. Only one nucleoside and two nonnucleoside RTI-DRMs differed by subtype/circulating recombinant form.

CONCLUSION

This study validates the global robustness of the actual DRM repertoire, in particular for circulating recombinant form 02 predominating in West and Central Africa, despite our finding of five additional selected mutations. However, long-term ART without virological monitoring clearly leads to the accumulation of mutations and the emergence of additional variations, which limit drug options for treatment and can be transmitted. Improved monitoring and optimization of ART are necessary for the long-term effectiveness of ART.

Should viral load thresholds be lowered?: Revisiting the WHO definition for virologic failure in patients on antiretroviral therapy in resource-limited settings

The World Health Organization (WHO) guidelines on antiretroviral therapy (ART) define treatment failure as 2 consecutive viral loads (VLs) ≥1000 copies/mL. There is, however, little evidence supporting 1000 copies as an optimal threshold to define treatment failure. Objective of this study was to assess the correlation of the WHO definition with the presence of drug-resistance mutations in patients who present with 2 consecutive unsuppressed VL in a resource-limited setting.In 10 nurse-led clinics in rural Lesotho children and adults on first-line ART for ≥6 months received a first routine VL. Those with plasma VL ≥80 copies/mL were enrolled in a prospective study, receiving enhanced adherence counseling (EAC) and a follow-up VL after 3 months. After a second unsuppressed VL genotypic resistance testing was performed. Viruses with major mutations against ≥2 drugs of the current regimen were classified as "resistant".A total of 1563 adults and 191 children received a first routine VL. Of the 138 adults and 53 children with unsuppressed VL (≥80 copies/mL), 165 (116 adults; 49 children) had a follow-up VL after EAC; 108 (74 adults; 34 children) remained unsuppressed and resistance testing was successful. Ninety of them fulfilled the WHO definition of treatment failure (both VL ≥1000 copies/mL); for another 18 both VL were unsuppressed but with <1000 copies/mL. The positive predictive value (PPV) for the WHO failure definition was 81.1% (73/90) for the presence of resistant virus. Among the 18 with VL levels between 80 and 1000 copies/mL, thereby classified as "non-failures", 17 (94.4%) harbored resistant viruses. Lowering the VL threshold from 1000 copies/mL to 80 copies/mL at both determinations had no negative influence on the PPV (83.3%; 90/108).The current WHO-definition misclassifies patients who harbor resistant virus at VL below 1000 c/mL as "nonfailing." Lowering the threshold to VL ≥80 copies/mL identifies a significantly higher number of patients with treatment-resistant virus and should be considered.

HIV virological failure and drug resistance in a cohort of Tanzanian HIV-infected adults

OBJECTIVES

There are few data on ART failure rates and drug resistance from Tanzania, where there is a wide diversity of non-B HIV subtypes. We assessed rates and predictors of virological failure in HIV-infected Tanzanians and describe drug resistance patterns in a subgroup of these patients.

METHODS

ART-naive, HIV-1-infected adults enrolled in a randomized controlled trial between November 2006 and 2008 and on ≥24 weeks of first-line NNRTI-containing ART were included. Population-based genotyping of HIV-1 protease and reverse transcriptase was performed on stored plasma from patients with virological failure (viral load >1000 copies/mL at ≥24 weeks of ART) and at baseline, where available.

RESULTS

A total of 2403 patients [median (IQR) age 37 (32-43) years; 70% female] were studied. The median (IQR) baseline CD4+ T cell count was 128 (62-190) cells/μL. Predominant HIV subtypes were A, C and D (92.2%). The overall rate of virological failure was 14.9% (95% CI 13.2%-16.1%). In adjusted analyses, significant predictors of virological failure were lower CD4+ T cell count (P = 0.01) and non-adherence to ART (P < 0.01). Drug resistance mutations were present in 87/115 samples (75.7%); the most common were M184V/I (52.2%) and K103N (35%). Thymidine analogue mutations were uncommon (5.2%). The prevalence of mutations in 45 samples pre-ART was 22%.

CONCLUSIONS

High levels of early ART failure and drug resistance were observed among Tanzanian HIV-1-infected adults enrolled in a well-monitored study. Initiating treatment early and ensuring optimal adherence are vital for the success and durability of first-line ART in these settings.

Phenotype, Genotype, and Drug Resistance in Subtype C HIV-1 Infection

BACKGROUND

Virologic failure in subtype C is characterized by high resistance to first-line antiretroviral (ARV) drugs, including efavirenz, nevirapine, and lamivudine, with nucleoside resistance including type 2 thymidine analog mutations, K65R, a T69del, and M184V. However, genotypic algorithms predicting resistance are mainly based on subtype B viruses and may under- or overestimate drug resistance in non-B subtypes. To explore potential treatment strategies after first-line failure, we compared genotypic and phenotypic susceptibility of subtype C human immunodeficiency virus 1 (HIV-1) following first-line ARV failure.

METHODS

AIDS Clinical Trials Group 5230 evaluated patients failing an initial nonnucleoside reverse-transcriptase inhibitor (NNRTI) regimen in Africa and Asia, comparing the genotypic drug resistance and phenotypic profile from the PhenoSense (Monogram). Site-directed mutagenesis studies of K65R and T69del assessed the phenotypic impact of these mutations.

RESULTS

Genotypic algorithms overestimated resistance to etravirine and rilpivirine, misclassifying 28% and 32%, respectively. Despite K65R with the T69del in 9 samples, tenofovir retained activity in >60%. Reversion of the K65R increased susceptibility to tenofovir and other nucleosides, while reversion of the T69del showed increased resistance to zidovudine, with little impact on other NRTI.

CONCLUSIONS

Although genotype and phenotype were largely concordant for first-line drugs, estimates of genotypic resistance to etravirine and rilpivirine may misclassify subtype C isolates compared to phenotype.

Risk factors and mortality associated with resistance to first-line antiretroviral therapy: multicentric cross-sectional and longitudinal analyses

BACKGROUND

Understanding the factors associated with HIV drug resistance development and subsequent mortality is important to improve clinical patient management.

METHODS

Analysis of individual electronic health records from 4 HIV programs in Malawi, Kenya, Uganda, and Cambodia, linked to data from 5 cross-sectional virological studies conducted among patients receiving first-line antiretroviral therapy (ART) for ≥6 months. Adjusted logistic and Cox-regression models were used to identify risk factors for drug resistance and subsequent mortality.

RESULTS

A total of 2257 patients (62% women) were included. At ART initiation, median CD4 cell count was 100 cells per microliter (interquartile range, 40-165). A median of 25.1 months after therapy start, 18% of patients had ≥400 and 12.4% ≥1000 HIV RNA copies per milliliter. Of 180 patients with drug resistance data, 83.9% had major resistance(s) to nucleoside or nonnucleoside reverse transcriptase inhibitors, and 74.4% dual resistance. Resistance to nevirapine, lamivudine, and efavirenz was common, and 6% had etravirine cross-resistance. Risk factors for resistance were young age (<35 years), low CD4 cell count (<200 cells/μL), and poor treatment adherence. During 4978 person-years of follow-up after virological testing (median = 31.8 months), 57 deaths occurred [rate = 1.14/100 person-years; 95% confidence interval (CI): 0.88 to 1.48]. Mortality was higher in patients with resistance (hazard ratio = 2.08; 95% CI: 1.07 to 4.07 vs. <400 copies/mL), and older age (hazard ratio = 2.41; 95% CI: 1.24 to 4.71 for ≥43 vs. ≤34 years), and lower in those receiving ART for >30 months.

CONCLUSIONS

Our findings underline the importance of optimal treatment adherence and adequate virological response monitoring and emphasize the need for resistance surveillance initiatives even in HIV programs achieving high virological suppression rates.

Use of amplification refractory mutation system PCR assay as a simple and effective tool to detect HIV-1 drug resistance mutations

Access to genotyping assays to determine successful antiretroviral treatment (ART) is limited in resource-constrained settings by high cost, suggesting the need for a cost-effective and simplified method to identify HIV-1 drug resistance (HIVDR) mutations. In this study, an amplification refractory mutation system (ARMS)-PCR assay was developed and used to investigate the most frequent HIVDR mutations affecting first-line ART in settings where WHO ART guidelines are applied. Seventy-five HIV-positive (HIV(+)) samples from Cameroon were used to assess the performance of this assay. Sequencing of HIV-1 reverse transcriptase was simultaneously performed for comparison, and discordant samples were tested with a Trugene HIV-1 genotyping kit. The ARMS-PCR assay was able to detect M184V, T215Y/F, K103N, and Y181C mutations with sensitivities of 96.8%, 85.7%, 91.3%, and 70%, respectively, and specificities of 90.6%, 95%, 100%, 96.9%, respectively, compared with data on sequencing. The results indicated the highest positive predictive value for K103N (100%) and the highest negative predictive value for M184V (97.5%). ARMS-PCR's limits of detection for mutations M184V, T215Y/F, K103N, and Y181C were <75 copies/ml, 143 copies/ml, 143 copies/ml, and 836 copies/ml, respectively. ARMS-PCR efficiently identified mutations in individuals harboring different HIV-1 clades (CRF02_AG and non-CRF02_AG). In addition, this approach was more cost-effective than other genotyping assays. The high throughput, the cost-effectiveness, and the simplicity of the ARMS-PCR assay make it a suitable tool to monitor HIVDR patterns in resource-constrained settings with broad HIV-1 genetic diversity.

[Long-term impact of antiretroviral therapy in Africa: current knowledge]

By the end of 2013, 11 million PLHIV were taking ARVs in Africa; application of the WHO recommendation to initiate treatment earlier (at CD4 count of 500 cells/mm3 or less) should further increase this number. Currently, twothirds of patients in Africa have been on treatment for less than five years, and less than 10% have received treatment for eight years or more. Given the historical perspective is in its early stages, the long-term impact of ARV therapy is still unclear. This article reviews the knowledge gained over the period marking the first ten years of implementation of the universal access strategy (2003-2013) in Africa, through a review of the literature documenting the long-term consequence of ARV treatment, focusing on medical care for adults with an emphasis on the patient-centered approach. The goal is to understand the interrelationships between biological and social factors and individual and collective aspects that affect the lives of PLHIV and determine the impacts of ARV treatment over the long term. The biomedical and social factors are addressed successively, based on the most significant results. Key knowledge on the long-term outcomes for PLHIVon ARV treatment offers vital information on the necessary conditions and adaptations for care systems needed to ensure the benefits of treatment endure over time.

HIV multi-drug resistance at first-line antiretroviral failure and subsequent virological response in Asia

Introduction

First-line antiretroviral therapy (ART) failure often results from the development of resistance-associated mutations (RAMs). Three patterns, including thymidine analogue mutations (TAMs), 69 Insertion (69Ins) and the Q151M complex, are associated with resistance to multiple-nucleoside reverse transcriptase inhibitors (NRTIs) and may compromise treatment options for second-line ART.

Methods

We investigated patterns and factors associated with multi-NRTI RAMs at first-line failure in patients from The TREAT Asia Studies to Evaluate Resistance – Monitoring study (TASER-M), and evaluated their impact on virological responses at 12 months after switching to second-line ART. RAMs were compared with the IAS-USA 2013 mutations list. We defined multi-NRTI RAMs as the presence of either Q151M; 69Ins; ≥2 TAMs; or M184V+≥1 TAM. Virological suppression was defined as viral load (VL) <400 copies/ml at 12 months from switch to second-line. Logistic regression was used to analyze (1) factors associated with multi-NRTI RAMs at first-line failure and (2) factors associated with virological suppression after 12 months on second-line.

Results

A total of 105 patients from 10 sites in Thailand, Hong Kong, Indonesia, Malaysia and Philippines were included. There were 97/105 (92%) patients harbouring ≥1 RAMs at first-line failure, 39/105 with multi-NRTI RAMs: six with Q151M; 24 with ≥2 TAMs; and 32 with M184V+≥1 TAM. Factors associated with multi-NRTI RAMs were CD4 ≤200 cells/µL at genotyping (OR=4.43, 95% CI [1.59–12.37], p=0.004) and ART duration >2 years (OR=6.25, 95% CI [2.39–16.36], p<0.001). Among 87/105 patients with available VL at 12 months after switch to second-line ART, virological suppression was achieved in 85%. The median genotypic susceptibility score (GSS) for the second-line regimen was 2.00. Patients with ART adherence ≥95% were more likely to be virologically suppressed (OR=9.33, 95% CI (2.43–35.81), p=0.001). Measures of patient resistance to second-line ART, including the GSS, were not significantly associated with virological outcome.

Conclusions

Multi-NRTI RAMs at first-line failure were associated with low CD4 level and longer duration of ART. With many patients switching to highly susceptible regimens, good adherence was still crucial in achieving virological response. This emphasizes the importance of continued adherence counselling well into second-line therapy.

Second-line failure and first experience with third-line antiretroviral therapy in Mumbai, India

BACKGROUND

There are limited data on the failure of second-line antiretroviral therapy (ART) and the use of third-line ART in people living with HIV in resource-limited settings. Since 2011, the Médecins Sans Frontières (MSF) HIV/tuberculosis programme in Mumbai, India, has been providing third-line ART to patients in care.

OBJECTIVE

To describe the experiences and programmatic challenges during management of suspected second-line ART failure and third-line ART therapy for patients living with HIV, including the use of HIV viral load (VL) testing.

DESIGN

This was a retrospective, observational cohort study of patients with suspected second-line ART treatment failure, who were followed for at least 12 months between January 2011 and March 2014.

RESULTS

A total of 47 patients with suspected second-line failure met the inclusion criteria during the study period. Twenty-nine of them (62%) responded to enhanced adherence support, had a subsequent undetectable VL after a median duration of 3 months and remained on second-line ART. The other 18 patients had to be initiated on a third-line ART regimen, which consisted of darunavir-ritonavir, raltegravir, and one or more appropriate nucleoside or nucleotide reverse transcriptase inhibitors, based on the results of HIV genotype testing. Of the 13 patients for whom follow-up VL results were available, 11 achieved virological suppression after a median duration of 3 months on third-line ART (interquartile range: 2.5-3.0). No serious treatment-related adverse events were recorded.

CONCLUSIONS

With intensive counselling and adherence support in those suspected of failing second-line ART, unnecessary switching to more expensive third-line ART can be averted in the majority of cases. However, there is an increasing need for access to third-line ART medications such as darunavir and raltegravir, for which national ART programmes should be prepared. The cost of such medications and inadequate access to VL monitoring and HIV genotype testing are currently major barriers to optimal management of patients failing second-line ART.

High level of HIV-1 resistance in patients failing long-term first-line antiretroviral therapy in Mali

OBJECTIVES

In resource-limited settings, few data are available on virological failure after long-term first-line antiretroviral therapy. This study characterized the genotypic resistance patterns at the time of failure after at least 36 months of a first-line regimen in Mali, West Africa.

METHODS

Plasma samples from 84 patients who were receiving first-line antiretroviral treatment and with an HIV-1 RNA viral load (VL) >1000 copies/mL were analysed. Genotypic resistance testing was performed and HIV-1 drug resistance was interpreted according to the latest version of the National Agency for HIV and Hepatitis Research algorithm.

RESULTS

At the time of resistance testing, patients had been treated for a median of 60 months (IQR 36-132 months) and had a median CD4 cell count of 292 cells/mm(3) (IQR 6-1319 cells/mm(3)), a median HIV-1 RNA level of 28266 copies/mL (IQR 1000-2 93 495 copies/mL) and a median genotypic susceptibility score of 1 (IQR 1-4). The prevalence of nucleoside reverse transcriptase inhibitor (NRTI) and non-nucleoside reverse transcriptase inhibitor (NNRTI) resistance mutations was 78% and 82%, respectively. Viruses were resistant to at least one drug in 92% of cases. Although etravirine and rilpivirine were not used in the first-line regimens, viruses were resistant to etravirine in 34% of cases and to rilpivirine in 49% of cases. The treatment duration, median number of NRTI and NNRTI mutations and some reverse transcriptase mutations (T215Y/F/N, L210W, L74I, M41L and H221Y) were associated with the VL at virological failure.

CONCLUSIONS

This study demonstrated a high level of resistance to NRTIs and NNRTIs, compromising second-generation NNRTIs, for patients who stayed on long-term first-line regimens. It is crucial to expand the accessibility of virological testing in resource-limited settings to limit the expansion of resistance and preserve second-line treatment efficacy.

High rate of HIV resuppression after viral failure on first-line antiretroviral therapy in the absence of switch to second-line therapy

In a randomized comparison of nevirapine or abacavir with zidovudine plus lamivudine, routine viral load monitoring was not performed, yet 27% of individuals with viral failure at week 48 experienced resuppression by week 96 without switching. This supports World Health Organization recommendations that suspected viral failure should trigger adherence counseling and repeat measurement before a treatment switch is considered.