A retrospective survey of HIV drug resistance among patients 1 year after initiation of antiretroviral therapy at 4 clinics in Malawi

The HIV care cascade in sub-Saharan Africa: systematic review of published criteria and definitions

INTRODUCTION

The HIV care cascade examines the attrition of people living with HIV from diagnosis to the use of antiretroviral therapy (ART) and suppression of viral replication. We reviewed the literature from sub-Saharan Africa to assess the definitions used for the different steps in the HIV care cascade.

METHODS

We searched PubMed, Embase and CINAHL for articles published from January 2004 to December 2020. Longitudinal and cross-sectional studies were included if they reported on at least one step of the UNAIDS 90-90-90 cascade or two steps of an extended 7-step cascade. A step was clearly defined if authors reported definitions for numerator and denominator, including the description of the eligible population and methods of assessment or measurement. The review protocol has been published and registered in Prospero.

RESULTS AND DISCUSSION

Overall, 3364 articles were screened, and 82 studies from 19 countries met the inclusion criteria. Most studies were from Southern (38 studies, 34 from South Africa) and East Africa (29 studies). Fifty-eight studies (71.6%) were longitudinal, with a median follow-up of three years. The medium number of steps covered out of 7 steps was 3 (interquartile range [IQR] 2 to 4); the median year of publication was 2015 (IQR 2013 to 2019). The number of different definitions for the numerators ranged from four definitions (for step "People living with HIV") to 21 (step "Viral suppression"). For the denominators, it ranged from three definitions ("Diagnosed and aware of HIV status") to 14 ("Viral suppression"). Only 12 studies assessed all three of the 90-90-90 steps. Most studies used longitudinal data, but denominator-denominator or denominator-numerator linkages over several steps were rare. Also, cascade data are lacking for many countries. Our review covers the academic literature but did not consider other data, such as government reports on the HIV care cascade. Also, it did not examine disengagement and reengagement in care.

CONCLUSIONS

The proportions of patients retained at each step of the HIV care cascade cannot be compared between studies, countries and time periods, nor meta-analysed, due to the many different definitions used for numerators and denominators. There is a need for standardization of methods and definitions.

Viral Suppression and HIV Drug Resistance at 6 Months Among Women in Malawi's Option B+ Program: Results From the PURE Malawi Study

BACKGROUND

In 2011, Malawi launched Option B+, a program of universal antiretroviral therapy (ART) treatment for pregnant and lactating women to optimize maternal health and prevent pediatric HIV infection. For optimal outcomes, women need to achieve HIVRNA suppression. We report 6-month HIVRNA suppression and HIV drug resistance in the PURE study.

METHODS

PURE study was a cluster-randomized controlled trial evaluating 3 strategies for promoting uptake and retention; arm 1: Standard of Care, arm 2: Facility Peer Support, and arm 3: Community Peer support. Pregnant and breastfeeding mothers were enrolled and followed according to Malawi ART guidelines. Dried blood spots for HIVRNA testing were collected at 6 months. Samples with ART failure (HIVRNA ≥1000 copies/ml) had resistance testing. We calculated odds ratios for ART failure using generalized estimating equations with a logit link and binomial distribution.

RESULTS

We enrolled 1269 women across 21 sites in Southern and Central Malawi. Most enrolled while pregnant (86%) and were WHO stage 1 (95%). At 6 months, 950/1269 (75%) were retained; 833/950 (88%) had HIVRNA testing conducted, and 699/833 (84%) were suppressed. Among those with HIVRNA ≥1000 copies/ml with successful amplification (N = 55, 41% of all viral loads > 1000 copies/ml), confirmed HIV resistance was found in 35% (19/55), primarily to the nonnucleoside reverse transcriptase inhibitor class of drugs. ART failure was associated with treatment default but not study arm, age, WHO stage, or breastfeeding status.

CONCLUSIONS

Virologic suppression at 6 months was <90% target, but the observed confirmed resistance rates suggest that adherence support should be the primary approach for early failure in option B+.

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.

Drug Resistance and Virological Failure among HIV-Infected Patients after a Decade of Antiretroviral Treatment Expansion in Eight Provinces of China

Background

China’s National Free Antiretroviral Treatment Program (NFATP) has substantially increased the survival rate since 2002. However, the emergence of HIV drug resistance (HIVDR) limits the durability and effectiveness of antiretroviral treatment (ART) in at risk patients.

Method

A cross-sectional survey was conducted among patients having received a median of 13.9 months of ART in eight provinces in China. Demographic and clinical information was collected, and venous blood was sampled for CD4 cell counts, measurement of the HIV viral load (VL), and HIV drug resistance (HIVDR) genotyping. Possible risk factors for HIVDR were analyzed by the logistic regression model.

Results

The study included 765 patients. Among them, 65 patients (8.5%) had virological failure (VLF) defined as ≥1,000 copies/ml. Among the individuals with VLF, 64 were successful genotyped, and of these, 33 had one or more HIVDR mutations. The prevalence of HIVDR mutations among patients receiving first-line ART was 4.3% (33/765). All of the patients with HIVDR mutations were resistant to non-nucleoside transcriptase inhibitors, 81.8% were resistant to nucleoside reverse transcriptase inhibitors, and only 3% had mutations that caused resistance to protease inhibitors. Having lower ratios of drug intake in the past month and dwelling in two southwestern provinces were factors independently associated with the emergence of HIVDR.

Conclusion

Most patients receiving first-line ART treatment achieved sound virological and immunological outcomes. However, poor adherence is still a key problem, which has led to the high rate of HIVDR. It was notable that the proportion of drug resistance widely varied among the provinces. More studies are needed to focus on adherence.

Drug resistance mutations after the first 12 months on antiretroviral therapy and determinants of virological failure in Rwanda

OBJECTIVE

To evaluate HIV drug resistance (HIVDR) and determinants of virological failure in a large cohort of patients receiving first-line tenofovir-based antiretroviral therapy (ART) regimens.

METHODS

A nationwide retrospective cohort from 42 health facilities was assessed for virological failure and development of HIVDR mutations. Data were collected at ART initiation and at 12 months of ART on patients with available HIV-1 viral load (VL) and ART adherence measurements. HIV resistance genotyping was performed on patients with VL ≥1000 copies/ml. Multiple logistic regression was used to determine factors associated with treatment failure.

RESULTS

Of 828 patients, 66% were women, and the median age was 37 years. Of the 597 patients from whom blood samples were collected, 86.9% were virologically suppressed, while 11.9% were not. Virological failure was strongly associated with age <25 years (adjusted odds ratio [aOR]: 6.4; 95% confidence interval [CI]: 3.2-12.9), low adherence (aOR: 2.87; 95% CI: 1.5-5.0) and baseline CD4 counts <200 cells/μl (aOR 3.4; 95% CI: 1.9-6.2). Overall, 9.1% of all patients on ART had drug resistance mutations after 1 year of ART; 27% of the patients who failed treatment had no evidence of HIVDR mutations. HIVDR mutations were not observed in patients on the recommended second-line ART regimen in Rwanda.

CONCLUSIONS

The last step of the UNAIDS 90-90-90 target appears within grasp, with some viral failures still due to non-adherence. Nonetheless, youth and late initiators are at higher risk of virological failure. Youth-focused programmes could help prevent further drug HIVDR development.

Virological Response and Antiretroviral Drug Resistance Emerging during Antiretroviral Therapy at Three Treatment Centers in Uganda

Background

With the scale-up of antiretroviral therapy (ART), monitoring programme performance is needed to maximize ART efficacy and limit HIV drug resistance (HIVDR).

Methods

We implemented a WHO HIVDR prospective survey protocol at three treatment centers between 2012 and 2013. Data were abstracted from patient records at ART start (T1) and after 12 months (T2). Genotyping was performed in the HIV pol region at the two time points.

Results

Of the 425 patients enrolled, at T2, 20 (4.7%) had died, 66 (15.5%) were lost to follow-up, 313 (73.6%) were still on first-line, 8 (1.9%) had switched to second-line, 17 (4.0%) had transferred out and 1 (0.2%) had stopped treatment. At T2, 272 out of 321 on first and second line (84.7%) suppressed below 1000 copies/ml and the HIV DR prevention rate was 70.1%, just within the WHO threshold of ≥70%. The proportion of participants with potential HIVDR was 20.9%, which is higher than the 18.8% based on pooled analyses from African studies. Of the 35 patients with mutations at T2, 80% had M184V/I, 65.7% Y181C, and 48.6% (54.8% excluding those not on Tenofovir) had K65R mutations. 22.9% had Thymidine Analogue Mutations (TAMs). Factors significantly associated with HIVDR prevention at T2 were: baseline viral load (VL) <100,000 copies/ml [Adjusted odds ratio (AOR) 3.13, 95% confidence interval (CI): 1.36–7.19] and facility. Independent baseline predictors for HIVDR mutations at T2 were: CD4 count <250 cells/μl (AOR 2.80, 95% CI: 1.08–7.29) and viral load ≥100,000 copies/ml (AOR 2.48, 95% CI: 1.00–6.14).

Conclusion

Strengthening defaulter tracing, intensified follow-up for patients with low CD4 counts and/or high VL at ART initiation together with early treatment initiation above 250 CD4 cells/ul and adequate patient counselling would improve ART efficacy and HIVDR prevention. The high rate of K65R and TAMs could compromise second line regimens including NRTIs.

Virological outcome among HIV-1 infected patients on first-line antiretroviral treatment in semi-rural HIV clinics in Togo

Background

Access to antiretroviral treatment (ART) in resource-limited countries has increased significantly but scaling-up ART into semi-rural and rural areas is more recent. Information on treatment outcome in such areas is still very limited notably due to additional difficulties to manage ART in these areas.

Results

387 HIV-1 infected adults (≥18 years) were consecutively enrolled when attending healthcare services for their routine medical visit at 12 or 24 months on first-line ART in five HIV care centers (four semi-rural and one rural). Among them, 102 patients were on first-line ART for 12 ± 2 months (M12) and 285 for 24 ± 2 months (M24). Virological failure was observed in 70 (18.1 %) patients ranging from 13.9 to 31.6 % at M12 and from 8.1 to 22.4 % at M24 across the different sites. For 67/70 patients, sequencing was successful and drug resistance mutations were observed in 65 (97 %). The global prevalence of drug resistance in the study population was thus at least 16.8 % (65/387). Moreover, 32 (8.3 %) and 27 (6.9 %) patients were either on a completely ineffective ART regime or with only a single drug active. Several patients accumulated high numbers of mutations and developed also cross-resistance to abacavir, didanosine or the new NNRTI drugs like etravirine and rilpivirine.

Conclusion

The observations on ART treatment outcome from ART clinics in semi-rural areas are close to previous observations in Lomé, the capital city suggesting that national ART-programme management plays a role in treatment outcome.

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.

Increasing rate of TAMs and etravirine resistance in HIV-1-infected adults between 12 and 24 months of treatment: the VOLTART cohort study in Côte d'Ivoire, West Africa

BACKGROUND

In sub-Saharan Africa, most HIV-infected patients receive antiretroviral therapy (ART) without virological monitoring. Longitudinal data on secondary resistance are rare.

METHODS

We conducted a prospective cohort study of HIV-1-infected adults initiating ART in 3 clinics using computerized monitoring systems. Patients had plasma HIV-1 RNA viral load (VL) tests at months 12 (M12) and 24 (M24) after ART initiation and HIV-1 resistance genotype tests if VL was detectable (≥300 copies/mL).

RESULTS

Overall, 1573 patients initiated ART with stavudine/zidovudine plus lamivudine plus nevirapine/efavirenz. At M12 and M24, 944 and 844 patients, respectively, remained in active follow-up. Among them, 25% (M12) and 27% (M24) had detectable VLs and 12% (M12) and 19% (M24) had virus resistant to at least 1 antiretroviral drug, accounting for 54% (M12) and 75% (M24) of patients with detectable VLs. Among the resistant strains, 95% (M12) and 97% (M24) were resistant to lamivudine/emtricitabine, efavirenz, and/or nevirapine, the frequency of thymidine analog mutations increased from 8.1% (M12) to 14.7% (M24) and etravirine resistance increased from 13.5% (M12) to 24.5% (M24).

CONCLUSIONS

Of the patients with detectable VLs at M24, 25% still did not harbor resistant virus. Preventing mutations from emerging with adherence reinforcement in patients with detectable VLs remains important beyond M24. Switching therapy early in patients with resistance to 3 TC/FTC and/or to nonnucleoside reverse transcriptase inhibitors to prevent extended resistance to nucleoside reverse transcriptase inhibitors and etravirine resistance from occurring is also a major challenge.

Emergence of HIV drug resistance during first- and second-line antiretroviral therapy in resource-limited settings

INTRODUCTION

Antiretroviral therapy (ART) in resource-limited settings has expanded in the last decade, reaching >8 million individuals and reducing AIDS mortality and morbidity. Continued success of ART programs will require understanding the emergence of HIV drug resistance patterns among individuals in whom treatment has failed and managing ART from both an individual and public health perspective. We review data on the emergence of HIV drug resistance among individuals in whom first-line therapy has failed and clinical and resistance outcomes of those receiving second-line therapy in resource-limited settings.

RESULTS

Resistance surveys among patients initiating first-line nonnucleoside reverse-transcriptase inhibitor (NNRTI)-based therapy suggest that 76%-90% of living patients achieve HIV RNA suppression by 12 months after ART initiation. Among patients with detectable HIV RNA at 12 months, HIV drug resistance, primarily due to M184V and NNRTI mutations, has been identified in 60%-72%, although the antiretroviral activity of proposed second-line regimens has been preserved. Complex mutation patterns, including thymidine-analog mutations, K65R, and multinucleoside mutations, are prevalent among cases of treatment failure identified by clinical or immunologic methods. Approximately 22% of patients receiving second-line therapy do not achieve HIV RNA suppression by 6 months, with poor adherence, rather than HIV drug resistance, driving most failures. Major protease inhibitor resistance at the time of second-line failure ranges from 0% to 50%, but studies are limited.

CONCLUSIONS

Resistance of HIV to first-line therapy is predictable at 12 months when evaluated by means of HIV RNA monitoring and, when detected, largely preserves second-line therapy options. Optimizing adherence, performing resistance surveillance, and improving treatment monitoring are critical for long-term prevention of drug resistance.

NRTI backbone in HIV treatment: will it remain relevant?

Nucleoside reverse transcriptase inhibitors (NRTIs) remain a critical component of therapy for HIV-infected patients. The drugs are effective, relatively inexpensive and an important component of antiretroviral therapy (ART), particularly in areas where the introduction of effective therapy has been delayed. They are an essential part of initial therapy for HIV and for prevention of mother-to-child transmission; however, toxicities and resistance may limit their use. The role for pre-exposure prophylaxis (PrEP) to reduce sexual transmission of HIV is still undefined, but this use may have a significant impact on NRTI resistance worldwide, most particularly in areas where subtype C predominates. With increasing prevalence of resistant HIV, the approval of new agents that are effective against resistant virus, and those that use novel cellular targets, are essential. Large studies are now in progress examining the safety and efficacy of NRTI-sparing regimens, but results are not currently available. NRTIs may lose relevance in the not distant future unless steps are put in place to reduce the development and spread of NRTI-resistant viruses, and new NRTIs with minimal toxicity are developed that have a novel resistance profile. This article describes the principal NRTIs, their mechanism of action, and resistance and selected toxicities of the class and of the individual drugs.

Update on World Health Organization HIV drug resistance prevention and assessment strategy: 2004-2011

The HIV drug resistance (HIVDR) prevention and assessment strategy, developed by the World Health Organization (WHO) in partnership with HIVResNet, includes monitoring of HIVDR early warning indicators, surveys to assess acquired and transmitted HIVDR, and development of an accredited HIVDR genotyping laboratory network to support survey implementation in resource-limited settings. As of June 2011, 52 countries had implemented at least 1 element of the strategy, and 27 laboratories had been accredited. As access to antiretrovirals expands under the WHO/Joint United Nations Programme on HIV/AIDS Treatment 2.0 initiative, it is essential to strengthen HIVDR surveillance efforts in the face of increasing concern about HIVDR emergence and transmission.

Prevalence of HIV drug resistance before and 1 year after treatment initiation in 4 sites in the Malawi antiretroviral treatment program

Since 2004, the Malawi antiretroviral treatment (ART) program has provided a public health-focused system based on World Health Organization clinical staging, standardized first-line ART regimens, limited laboratory monitoring, and no patient-level monitoring of human immunodeficiency virus drug resistance (HIVDR). The Malawi Ministry of Health conducts periodic evaluations of HIVDR development in prospective cohorts at sentinel clinics. We evaluated viral load suppression, HIVDR, and factors associated with HIVDR in 4 ART sites at 12-15 months after ART initiation. More than 70% of patients initiating ART had viral suppression at 12 months. HIVDR prevalence (6.1%) after 12 months of ART was low and largely associated with baseline HIVDR. Better follow-up, removal of barriers to on-time drug pickups, and adherence education for patients 16-24 years of age may further prevent HIVDR.