HIV Drug Resistance Surveillance Research Articles

Gene mutations of human immunodeficiency virus drug resistance from men who have sex with men in Shanghai, 2013

Objective To investigate the gene mutations of human immunodeficiency virus (HIV)-1 drug resistance among anti-retrovirus (ARV) treated-naive men who have sex with men (MSM) in Shanghai to provide evidence-based data for optimized treatment. Methods All 669 treatment-naive cases of HIV-1 infection identified among MSM in 2013 were recruited and their plasma was collected. RNA was extracted and amplified by nest reverse transcription-polymerase chain reaction, and DNA was sequenced and then phylogenetically analyzed. Finally, subtypes were identified and drug resistance was analyzed in comparison with International HIV Drug Resistance Database. Results The pol gene fragments of 645 cases were obtained. Primary drug-resistance rate was 2.48% (16/645), including mutations conferring resistance to protease inhibitor (PI) (0.31%, 2/645), nucleoside reverse transcriptase inhibitors (NRTI) (0.16%, 1/645), non-nucleoside reverse transcriptase inhibitors (NNRTI) (1.70%, 11/645) and both NRTI and NNRTI (0.31%, 2/645), respectively. Mutations conferring resistance to CRF01_AE were 12 cases (2.99%), while mutations conferring resistance to CRF07_BC and CRF_01B were 0.61% (1/163) and 4.65% (2/43) including 1 case of CRF52_01B and unidentified CRF_01B, respectively. Resistance to NNRTI in B subtype were 2.70% (1/37). Conclusion The prevalence of HIV-1 drug resistance-associated mutations among MSM in Shanghai, 2013 is still low, but resistance to NNRTI is relatively high. CRF01_AE is the major subtype of drug resistance. It is necessary to strengthen the HIV drug resistance surveillance in MSM group in Shanghai. Key words: Human immunodeficiency virus-1; Homosexuality, male; Subtype/recombinant; Drug resistance

HIV Drug Resistance Surveillance in Honduras after a Decade of Widespread Antiretroviral Therapy.

IntroductionWe assessed HIV drug resistance (DR) in individuals failing ART (acquired DR, ADR) and in ART-naïve individuals (pre-ART DR, PDR) in Honduras, after 10 years of widespread availability of ART.Methods365 HIV-infected, ART-naïve, and 381 ART-experienced Honduran individuals were enrolled in 5 reference centres in Tegucigalpa, San Pedro Sula, La Ceiba, and Choluteca between April 2013 and April 2015. Plasma HIV protease-RT sequences were obtained. HIVDR was assessed using the WHO HIVDR mutation list and the Stanford algorithm. Recently infected (RI) individuals were identified using a multi-assay algorithm.ResultsPDR to any ARV drug was 11.5% (95% CI 8.4–15.2%). NNRTI PDR prevalence (8.2%) was higher than NRTI (2.2%) and PI (1.9%, p<0.0001). No significant trends in time were observed when comparing 2013 and 2014, when using a moving average approach along the study period or when comparing individuals with >500 vs. <350 CD4+ T cells/μL. PDR in recently infected individuals was 13.6%, showing no significant difference with PDR in individuals with longstanding infection (10.7%). The most prevalent PDR mutations were M46IL (1.4%), T215 revertants (0.5%), and K103NS (5.5%). The overall ADR prevalence in individuals with <48 months on ART was 87.8% and for the ≥48 months on ART group 81.3%. ADR to three drug families increased in individuals with longer time on ART (p = 0.0343). M184V and K103N were the most frequent ADR mutations. PDR mutation frequency correlated with ADR mutation frequency for PI and NNRTI (p<0.01), but not for NRTI. Clusters of viruses were observed suggesting transmission of HIVDR both from ART-experienced to ART-naïve individuals and between ART-naïve individuals.ConclusionsThe global PDR prevalence in Honduras remains at the intermediate level, after 10 years of widespread availability of ART. Evidence of ADR influencing the presence of PDR was observed by phylogenetic analyses and ADR/PDR mutation frequency correlations.

Reductions in virological failure and drug resistance to antiretroviral therapy in Chinese patients associated with lamivudine-based regimens, 2003–12: a cross-sectional study

BackgroundChina's National Free Antiretroviral Treatment Program has substantially scaled up and standardised antiretroviral treatment (ART) since 2008. Meanwhile, no study worldwide has examined the effects of rapid ART programme scale-up on treatment outcomes in resource-limited settings on a large scale. MethodsThe national HIV drug resistance surveillance database included annual cross-sectional surveys HIV drug resistance from 2003–12. We used China's national HIV drug resistance surveillance database to determine virological failure, acquired drug resistance, and poor adherence after 12–15 months of first-line ART. The probability proportional to proxy size (PPPS) sampling recommended by WHO was used in this study. χ tests and logistic regression were used for categorical variables. The institutional review board of the National Center on HIV/STD Control and Prevention (NCAIDS), China CDC, approved this study. FindingsOf the 2252 patients included in this study, 1180 (52%) were aged less than 40 years; 2100 (93%) belonged to the Han ethnic group; 1331 (59%) were male; 963 (43%) had primary school (1–6 years of education) or less; 1665 (74%) were married; 968 (43%) were farmers; 929 (41%), 947 (42%), and 322 (14%) were infected through blood or plasma transmission, sexual intercourse, and intravenous drug use, respectively. 1431 (64%) patients had initiated ART before 2008, and 821 (36%) initiated ART after 2008. The incidence of virological failure after 12–15 months of treatment was lower in the group of patients who had initiated ART after 2008 than in the group of patients who initiated ART before 2008 (12·1% vs 26·6%). The incidence of HIV drug resistance to ART was also significantly reduced in patients who initiated ART after 2008 compared to patients who intiated treatment before 2008 (5·4% vs 15·4%). However, these improvements are strongly associated with the standardised use of lamivudine-based regimens instead of didanosine-based regimens. Patients who initiated lamivudine-based regimens before 2008 had significant improvement in adherence (missed doses adjusted odds ratio [AOR] 0·65, 95% CI 0·45–0·96), virological failure (AOR 0·29 95% CI 0·22–0·39), and drug resistance outcomes (AOR 0·29 95% CI 0·20–0·42) compared with those who initiated didanosine-based regimens. We found no significant changes in these outcomes between patients who initiated lamivudine-based regimens before 2008 and those who initiated this treatment after 2008. InterpretationChina's National Free Antiretroviral Treatment Program has been largely successful throughout the scale-up, with an overall reduction in virological failure and HIV drug resistance. However, excluding the effect of lamivudine-based regimens, the programme must improve patient adherence and quality of care, particularly in key vulnerable populations such as those infected through injecting drug use or blood routes. Further monitoring of treatment outcomes is needed to elucidate the determinants of long-term programmatic success. This is the first large scale study in the world evaluating the outcomes of ART treatment during a rapid programmatic scale-up. FundingMinistry of Science and Technology of China (grants 2012ZX10001-002 and 2009DFB30420), Chinese State Key Laboratory for Infectious Disease (development grant 2012SKLID103), and International Development Research Center of Canada (grant 104519-010). The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript.

HIV Phylogeographic Analyses and Their Application in Prevention and Early Detection Programmes: The Case of the Tijuana–San Diego Border Region

HIV Phylogeographic Analyses and Their Application in Prevention and Early Detection Programmes: The Case of the Tijuana–San Diego Border Region

HIV Drug Resistance Surveillance Among Jamaican Men Who Have Sex with Men Should Be Prioritized for Reducing HIV Transmission.

The prevalence of human immunodeficiency virus type 1 (HIV-1) is highest among men who have sex with men (MSM) in Jamaica but no genotypic data are available on the virus strains that are responsible for the epidemic among this key population. HIV-1 polymerase (pol) genes from 65 MSM were sequenced and used to predict drug resistance mutations. An HIV drug resistance prevalence of 28% (minimum 13%) was observed among this cohort, with the most frequent mutations conferring resistance to efavirenz, nevirapine, and lamivudine. Phylogenetic analysis of the sequences revealed 10 times the number of linked HIV infections among this cohort than respondent reporting. HIV treatment and prevention efforts in Jamaica could benefit significantly from Pol genotyping of the HIV strains infecting socially vulnerable MSM prior to initiating antiretroviral therapy (ART), as this would guide suppressive ART and unearth HIV transmission clusters to enable more effective delivery of treatment and prevention programs.

Reductions in virological failure and drug resistance in Chinese antiretroviral-treated patients due to lamivudine-based regimens, 2003-12.

China's National Free Antiretroviral Treatment Program (NFATP) has significantly scaled up and standardized treatment since 2008. Meanwhile, no study worldwide has examined on a large scale the effects of rapid ART programme scale-up on treatment outcomes in resource-limited settings. We used China's national HIV drug resistance (HIVDR) surveillance database to determine virological failure, acquired drug resistance and poor adherence rates after 12-15 months of first-line ART. A total of 2252 patients were examined, with 1431 patients having initiated ART before 2008 and 821 since 2008. Since 2008, virological failure at 12-15 months of treatment improved from 26.6% to 12.1%, and HIVDR rates also significantly decreased from 15.4% to 5.4%. However, these successes are strongly associated with the standardized use of lamivudine-based regimens in place of didanosine-based regimens. Patients who initiated lamivudine-based regimens before 2008 showed significant improvement in adherence [missed doses adjusted OR (AOR), 0.65; 95% CI, 0.45-0.96], virological failure (AOR, 0.29; 95% CI, 0.22-0.39) and HIVDR outcomes (AOR, 0.29; 95% CI, 0.20-0.42) compared with those who initiated didanosine-based regimens. Meanwhile, among only patients on lamivudine-based regimens, no significant changes were observed between those who initiated before 2008 and those who initiated since 2008. China's NFATP has been largely successful throughout the scale-up, with an overall reduction in virological failure and HIVDR. However, excluding the effect of lamivudine-based regimens, it remains crucial for the programme to improve patient adherence and quality of care, particularly in key vulnerable populations such as those infected through injecting drug or blood routes.

Population-based surveillance of HIV drug resistance emerging on treatment and associated factors at sentinel antiretroviral therapy sites in Namibia.

The World Health Organization (WHO) prospective surveys of acquired HIV drug resistance (HIVDR) evaluate HIVDR emerging after the first year of antiretroviral therapy (ART) and associated factors. Consecutive ART starters in 2009 were enrolled at 3 sentinel sites in Namibia. Genotyping was performed at start and after 12 months in patients with HIV viral load (VL) >1000 copies per mL. HIVDR outcomes were: HIVDR prevention (VL ≤1000 copies/mL), possible HIVDR (VL >1000 copies/mL without detectable HIVDR or loss to follow-up or ART stop), and HIVDR (VL >1000 copies/mL with detectable HIVDR). Adherence was assessed using medication possession ratio (MPR). Of 394 starters, at 12 months, 80% were on first-line ART, 1% died, 4% transferred out, 1% stopped ART, <1% switched to second-line, and 15% were lost to follow-up. Among patients on first-line, 77% had VL testing, and 94% achieved VL ≤1000 copies per mL. At baseline, 7% had HIVDR. After 12 months, among patients with VL testing, 5% had HIVDR. A majority of patients failing therapy had high-level resistance to nonnucleoside reverse transcriptase inhibitors but none to protease inhibitors. All sites achieved the WHO target of ≥70% HIVDR prevention. Factors associated with not achieving HIVDR prevention were: baseline resistance to nonnucleoside reverse transcriptase inhibitors [odds ratio (OR) 3.0, P = 0.023], WHO stage 3 or 4 at baseline (OR 2.0, P = 0.012), and MPR <75% (OR 4.9, P = 0.021). Earlier ART initiation and removal of barriers to on-time drug pickups may help to prevent HIVDR. These data inform decisions at national and global levels on the effectiveness of first- and second-line regimens.

Prevalence of Transmitted HIV-1 Drug Resistance among Young Adults Attending HIV Counselling and Testing Clinics in Kigali, Rwanda

Scaling-up antiretroviral therapy (ART) in resource-limited settings has raised concerns of emerging HIV drug resistance (DR) and its transmission to newly infected individuals. To assess the prevalence of transmitted drug resistance (TDR) in recently HIV-infected individuals, a WHO TDR threshold survey was conducted among young adults in Kigali, Rwanda. Between May and July 2011, HIV subtype and genotyping were performed on dried blood spots (DBS) prepared from blood specimens collected from newly HIV-diagnosed and ART-naive individuals aged 15 to 21 years in eight HIV voluntary counselling and testing (VCT) sites in Kigali. In total, 57 of the 68 DBS collected from eligible participants were successfully amplified. The median age of participants was 20 years and 86% were female. Most participants (96%) were infected with subtype A1 virus. Two participants (4%) had the K103N non-nucleoside reverse transcriptase inhibitor (NNRTI) mutation and one (2%) had the M46L protease inhibitor (PI) mutation. The TDR prevalence was 3.5% (95% CI 0.4, 12.1) for NNRTI and 1.8% (95% CI 0.0, 9.4) for PI. The prevalence of HIV TDR in VCT attendees in Kigali was characterized as low (<5%) for all drug classes according to the WHO HIV DR threshold survey methodology. Despite a decade of widespread ART in Rwanda, TDR prevalence remains low, and so the current first-line ART regimens should continue to be effective. However, as scale-up of ART continues, frequent HIV DR surveillance is needed to monitor the effectiveness of available ART regimens at the population level.

Epidemiological and molecular characteristics of HIV infection among money boys and general men who have sex with men in Shanghai, China

To examine and compare the epidemiological and molecular characteristics of HIV infection between money boys (MBs) and general men who have sex with men (MSM) in Shanghai, China. Using a venue-based sampling strategy, a total of 535 MSM including 226 MBs and 309 general MSM were recruited to participate in a cross-sectional survey including a face-to-face questionnaire interview and HIV testing. Genotyping of HIV-1 pol gene was performed for HIV-positive participants. Compared with general MSM, MBs reported more sexual partners, more alcohol and drug use and more sex after alcohol or drug use. HIV prevalence was 10.7% overall, 14.6% for MBs and 7.8% for general MSM (p=0.011). Two independent multiple logistic regression analyses indicated that HIV infection was positively associated with non-Han ethnicity (Odds Ratio [OR]=4.79, 95% Confidence Interval [CI]: 1.08–21.28) and sex after drug use in the past 6months (OR=3.59, 95% CI: 1.50–8.61) among MBs, and with sex after drug use in the past 6months (OR=3.38, 95% CI: 1.10–10.34) among general MSM as well. HIV-1 pol gene was successfully amplified and sequenced for 52 (91.2%) of HIV-positive participants. Of them, 53.8% were genotyped as CRF01_AE, 36.5% as CRF07_BC and 9.6% as subtype B. Two CRF01_AE subtype-infected participants (3.8%), a 50years old MB and a 24years old general MSM, harbored viruses with a M46L mutation conferring resistance to protease inhibitors (PI). MSM particularly MBs in Shanghai, China were at high risk of HIV infection, underscoring an urgent need for joint intervention efforts for drug use and sexual behaviors. HIV drug resistance surveillance is also warranted although the relatively low prevalence of HIV drug resistance implies the effectiveness of current antiretroviral treatment regimen.

HIV Drug Resistance Surveillance Among Jamaican Men Who Have Sex with Men Should Be Prioritized for Reducing HIV Transmission

HIV Drug Resistance Surveillance Among Jamaican Men Who Have Sex with Men Should Be Prioritized for Reducing HIV Transmission

The Prevalence of HIV Drug Resistance among Treatment-failure Individuals and Treatment-naïve Individuals in China: A Meta-analysis

ObjectiveTo understand drug resistance prevalence among treatment-failure and treatment-naïve HIV-positive individuals in China. MethodsWe searched five electronic databases (Wanfang, CNKI, CQVIP, SinoMed, and Pubmed) for studies of HIV drug resistance. Random-effects models were carried out to estimate the prevalence of drug resistance among treatment-failure and treatment-naïve individuals, respectively. ResultsThe estimated nationwide rates of HIV drug resistance to any-class drugs among treatment-failure and treatment-naïve individuals were 57% (95% CI: 49%-65%) and 3.23% (95% CI: 2.47%-4.07%), respectively. Among the drug classes, the prevalence of resistance to PIs was low (1.45%; 95% CI: 0.73%-2.33%) in treatment-failure individuals, although high rates of resistance to NNRTIs (54%; 95% CI: 45%-63%) and NRTIs (40%; 95% CI: 32%-49%) were found. Resistance to any-class drugs, NNRTIs and NRTIs manifested regional differences, but resistance to PIs did not. Positive correlations were observed between resistance to NNRTIs and NRTIs among treatment-failure and treatment-naïve individuals, respectively. ConclusionThe prevalence of HIV drug resistance to NNRTIs and NRTIs among treatment-failure individuals was high. In contrast, the prevalence of drug resistance among treatment-naïve individuals was low. The epidemics of drug resistance matched current treatment strategies and interventions in China. Surveillance for HIV drug resistance is necessary to assess the sustainability and durability of current treatment regimens.

HIV-1 drug resistance surveillance in antiretroviral treatment-naive individuals from a reference hospital in Guatemala, 2010-2013.

The recent expansion of antiretroviral treatment (ART) coverage in middle/low-income countries has been associated with increasing prevalence of HIV pre-ART drug resistance (PDR). We assessed PDR prevalence, patterns, and trends in Guatemala. Blood samples from 1,084 ART-naive individuals, enrolled from October 2010 to December 2013 at the Roosevelt Hospital in Guatemala City, were obtained. PDR was evaluated using the WHO mutation list for transmitted drug resistance (TDR) surveillance. An overall PDR prevalence of 7.3% (95% CI 5.8-9.0%) was observed for the whole study period. TDR to nonnucleoside reverse transcriptase inhibitors (NNRTI) was the highest (4.9%, p<0.001), followed by nucleoside RT inhibitors (1.8%) and protease inhibitors (1.0%). No significant trends in PDR prevalence were observed during the study period. However, higher NNRTI PDR levels were found in individuals with >500 and 350-500 CD4(+) T cells/μl (7.4% and 8.7%, respectively) compared to individuals with <350 CD4(+) T cells/μl (3.7%; p=0.039 and p=0.007, respectively), as well as a tendency of higher levels of NNRTI transmitted drug resistance (DR) in individuals with recent infection determined by HIV incidence tests (9.7%), suggesting increasing trends in time. Clusters of viruses with NNRTI PDR suggesting complex transmission networks were observed. No associations between PDR and demographic variables were found. PDR in Guatemala remains at an intermediate level. Nevertheless, we have shown evidence suggesting increasing trends in NNRTI PDR, which need to be taken into account in national HIV management policies.

The prevalence of HIV-1 drug resistance among antiretroviral treatment naïve individuals in mainland China: a meta-analysis.

BackgroundSurveillance of drug resistance in antiretroviral treatment-naïve patients in China is needed to ensure optimal treatment outcomes and control of the human immunodeficiency virus (HIV) epidemic.MethodsA systematic literature search was conducted in English and Chinese through PubMed (English), China National Knowledge Infrastructure (Chinese), Chinese Biomedical Literature Database (Chinese), and Wanfang (Chinese). Random effects models were used to calculate the pooled prevalence of transmitted drug resistance and subgroup analyses examined prevalence estimates across time periods, study locations, and study populations.ResultsAnalysis of data from 71 studies (47 in Chinese and 24 in English) yielded a pooled prevalence of transmitted HIV drug resistance to any antiretroviral drug class of 3.64% (95% confidence interval [CI]: 3.00%–4.32%). Rates were significantly high at initial stage of free ART program from 2003 to 2005 (5.18%, 95%CI: 3.13%–7.63%), and were much lower among studies conducted in 2006–2008 (3.02%, 95%CI: 2.03%–4.16%). A slight increase was observed again in the most recent study period from 2009 to 2012 (3.68%, 95%CI: 2.78%–4.69%). Subgroup analysis revealed highest prevalence levels of transmitted drug resistance in Beijing city, and Henan and Hubei provinces (above 5%), and although differences in prevalence rates among risk groups were negligible, men who have sex with men were unique in their relatively large portion of protease inhibitor resistance, a second-line drug of limited availability in China.ConclusionsOverall prevalence of transmitted HIV drug resistance in China is classified as “low” by the World Health Organization. However regional and temporal variability suggest a more complex epidemic for which closer HIV drug resistance surveillance is needed. A nationwide HIV drug resistance surveillance system to monitor both treatment-experienced and treatment-naïve patients will be a cornerstone to ensure the effectiveness of treatment scale-up, particularly as China seeks to expand a national policy of antiretroviral treatment as prevention.

HIV virological failure and drug resistance among injecting drug users receiving first-line ART in China

ObjectiveTo explore HIV virological failure and drug resistance among injecting drug users (IDUs) receiving first-line antiretroviral treatment (ART) in China.DesignA series of cross-sectional surveys from 2003 to 2012 from the...

Emerging trends of HIV drug resistance in Chinese HIV-infected patients receiving first-line highly active antiretroviral therapy: a systematic review and meta-analysis.

Highly active antiretroviral therapy (HAART) has led to a dramatic decrease in AIDS-related morbidity and mortality through sustained suppression of human immunodeficiency virus (HIV) replication and reconstitution of the immune response. Settings like China that experienced rapid HAART rollout and relatively limited drug selection face considerable challenges in controlling HIV drug resistance (DR). We conducted a systematic review and meta-analysis to describe trends in emergent HIV DR to first-line HAART among Chinese HIV-infected patients, as reflected in the point prevalence of HIV DR at key points and fixed intervals after treatment initiation, using data from cohort studies and cross-sectional studies respectively. Pooled prevalence of HIV DR from longitudinal cohorts studies was 10.79% (95% confidence interval [CI], 5.85%-19.07%) after 12 months of HAART and 80.58% (95% CI, 76.6%-84.02%) after 72 months of HAART. The HIV DR prevalence from cross-sectional studies was measured in treatment intervals; during the 0-12-month HAART treatment interval, the pooled prevalence of HIV DR was 11.1% (95% CI, 7.49%-16.14%), which increased to 22.92% at 61-72 months (95% CI, 9.45%-45.86%). Stratified analyses showed that patients receiving a didanosine-based regimen had higher HIV DR prevalence than those not taking didanosine (15.82% vs 4.97%). Patients infected through former plasma donation and those receiving AIDS treatment at village clinics had higher HIV DR prevalence than those infected through sexual transmission or treated at a county-level hospital. Our findings indicate higher prevalence of HIV DR for patients with longer cumulative HAART exposure, highlighting important subgroups for future HIV DR surveillance and control.

HIV drug resistance in newly diagnosed adults in a rural prefecture of eastern China.

Little is known about HIV drug resistance (HIVDR) in newly diagnosed HIV-infected adults in eastern China where the HIV epidemic is spreading predominantly through sexual contact. During 2008-2011, newly HIV-diagnosed adults in Taizhou prefecture, Zhejiang province in eastern China were examined for HIVDR by amplifying and sequencing the HIV-1 pol gene. Of 447 genotyped participants, 53·7% were infected with CRF01_AE, 20·1% with CRF07_BC, 12·5% with subtype B, and 11·6% with CRF08_BC. Most of the participants had one or more minor genetic mutations in the pol gene that are associated with HIVDR. Twelve (2·7%) participants met the standard guidelines of having low to high HIVDR, suggesting that the prevalence of HIVDR in newly HIV-diagnosed adults was low in the study area and current antiretroviral therapy (ART) regimens are likely to remain effective. However, given high frequency of minor HIVDR in HIV patients and the scaling up of ART programmes in China, larger HIVDR surveillance programmes are needed.

HIV-1 drug resistance in treatment-naive chronically infected patients in Jamaica.

HIV-1 drug resistance in treatment-naive patients has a significant impact on the individual patient as well as implications for the wider population. These effects are amplified in the context of resource-limited settings, which are rapidly expanding access to antiretroviral therapy. This cross-sectional survey at a single treatment site in Kingston, Jamaica was designed to identify the prevalence of HIV-1 drug-resistant mutations in chronically infected, treatment-naive patients. Mutations were identified using the Stanford HIV database algorithm and the World Health Organization (WHO) HIV Drug Resistance (HIVDR) surveillance mutations. The inclusion of 103 cases in the study resulted in 79 (76.6%) amplifiable samples. Genotype analysis revealed that 12.6% (95% CI 5.3, 19.9) were identified as having clinically significant mutations, while 10.1% (95% CI 3.5, 16.7) had WHO HIVDR surveillance mutations. According to the WHO standard, this study population has a moderate level of HIVDR in treatment-naive patients and strongly implies the need to introduce HIVDR surveillance in Jamaica.

Simultaneous Detection of Major Drug Resistance Mutations in the Protease and Reverse Transcriptase Genes for HIV-1 Subtype C by Use of a Multiplex Allele-Specific Assay

High-throughput, sensitive, and cost-effective HIV drug resistance (HIVDR) detection assays are needed for large-scale monitoring of the emergence and transmission of HIVDR in resource-limited settings. Using suspension array technology, we have developed a multiplex allele-specific (MAS) assay that can simultaneously detect major HIVDR mutations at 20 loci. Forty-five allele-specific primers tagged with unique 24-base oligonucleotides at the 5' end were designed to detect wild-type and mutant alleles at the 20 loci of HIV-1 subtype C. The MAS assay was first established and optimized with three plasmid templates (C-wt, C-mut1, and C-mut2) and then evaluated using 148 plasma specimens from HIV-1 subtype C-infected individuals. All the wild-type and mutant alleles were unequivocally distinguished with plasmid templates, and the limits of detection were 1.56% for K219Q and K219E, 3.13% for L76V, 6.25% for K65R, K70R, L74V, L100I, K103N, K103R, Q151M, Y181C, and I47V, and 12.5% for M41L, K101P, K101E, V106A, V106M, Y115F, M184V, Y188L, G190A, V32I, I47A, I84V, and L90M. Analyses of 148 plasma specimens revealed that the MAS assay gave 100% concordance with conventional sequencing at eight loci and >95% (range, 95.21% to 99.32%) concordance at the remaining 12 loci. The differences observed were caused mainly by 24 additional low-abundance alleles detected by the MAS assay. Ultradeep sequencing analysis confirmed 15 of the 16 low-abundance alleles. This multiplex, sensitive, and straightforward result-reporting assay represents a new efficient genotyping tool for HIVDR surveillance and monitoring.

HIV-1 Drug-Resistance Surveillance among Treatment-Experienced and -Naïve Patients after the Implementation of Antiretroviral Therapy in Ghana

BackgroundLimited HIV-1 drug-resistance surveillance has been carried out in Ghana since the implementation of antiretroviral therapy (ART). This study sought to provide data on the profile of HIV-1 drug resistance in ART-experienced and newly diagnosed individuals in Ghana.MethodsSamples were collected from 101 HIV-1-infected patients (32 ART-experienced cases with virological failure and 69 newly diagnosed ART-naïve cases, including 11 children), in Koforidua, Eastern region of Ghana, from February 2009 to January 2010. The pol gene sequences were analyzed by in-house HIV-1 drug-resistance testing.ResultsThe most prevalent HIV-1 subtype was CRF02_AG (66.3%, 67/101) followed by unique recombinant forms (25.7%, 26/101). Among 31 ART-experienced adults, 22 (71.0%) possessed at least one drug-resistance mutation, and 14 (45.2%) had two-class-resistance to nucleoside and non-nucleoside reverse-transcriptase inhibitors used in their first ART regimen. Importantly, the number of accumulated mutations clearly correlated with the duration of ART. The most prevalent mutation was lamivudine-resistance M184V (n = 12, 38.7%) followed by efavirenz/nevirapine-resistance K103N (n = 9, 29.0%), and zidovudine/stavudine-resistance T215Y/F (n = 6, 19.4%). Within the viral protease, the major nelfinavir-resistance mutation L90M was found in one case. No transmitted HIV-1 drug-resistance mutation was found in 59 ART-naïve adults, but K103N and G190S mutations were observed in one ART-naïve child.ConclusionsDespite expanding accessibility to ART in Eastern Ghana, the prevalence of transmitted HIV-1 drug resistance presently appears to be low. As ART provision with limited options is scaled up nationwide in Ghana, careful monitoring of transmitted HIV-1 drug resistance is necessary.

Prevalence of HIV-1 drug resistance in treated patients with viral load &gt;50 copies/mL in 2009: a French nationwide study

Surveillance of HIV-1 drug resistance in treated patients with plasma viral load (VL) >50 copies/mL. The protease and reverse transcriptase (RT) genes were systematically sequenced in samples from 756 patients with VL >50 copies/mL in 2009. The genotyping results were interpreted for each antiretroviral drug (ARV) by using the ANRS algorithm v21. Weighted analyses were used to derive representative estimates of percentages of patients. Prevalence rates were compared with those obtained in 2004 among patients with VL >1000 copies/mL. Sequences were obtained for 506 patients. Sequencing was successful in 45%, 80% and 96% of samples with VL of 51-500, 501-1000 and >1000 copies/mL, respectively. Resistance or possible resistance to at least one ARV was observed in 59% of samples. Overall, 0.9% of samples contained viruses resistant to all drugs belonging to at least three drug classes. All resistance prevalence rates were significantly lower in 2009 than in 2004. In France, where 86% of patients were receiving combination antiretroviral therapy in 2009, only 15.0% of patients had a VL >50 copies/mL, suggesting that only 8.9% of treated patients could potentially transmit resistant viruses. Only 0.08% of patients harboured viruses fully resistant to at least three antiretroviral drug classes. Further studies are needed to determine whether resistance continues to decline over time.