Transmitted Drug Resistance Mutations Research Articles

HIV-1 Genetic Diversity and Transmitted Drug Resistance in Antiretroviral Treatment-Naive Individuals from Amapá State, Northern Brazil.

The pattern of HIV-1 subtype distribution and prevalence of transmitted drug resistance mutations (TDRM) is heterogeneous across different Brazilian regions. Little information is available about the molecular epidemiologic profile in Northern Brazil. HIV-1 protease (PR) and reverse transcriptase (RT) sequences were obtained from 97 drug-naive HIV-1-infected individuals from Amapá, one of the most isolated Northern Brazilian states, for subtype determination and analysis of drug resistance mutations. The most prevalent HIV-1 clade observed in Amapá was subtype B (74%), followed by subtype F1 (14%), BF1 recombinants (8%), subtype C (1%), CRF31_BC (1%), and CRF02_AG (1%). Only one TDRM (K103N) was detected in a single patient from our study population. This study reveals that the HIV-1 epidemic in Amapá is characterized by a high level of genetic diversity comparable to that observed in major Brazilian cities, but a much lower rate of TDRM (1%).

Low prevalence of hepatitis C co-infection in recently HIV-infected minority men who have sex with men in Los Angeles: a cross-sectional study.

BackgroundGeographic and sociodemographic characterization of hepatitis C virus (HCV) transmission amongst men who have sex with men (MSM) has been limited. Our aim was to characterize HCV prevalence, risk factors for HCV co-infection, and patterns of HIV and HCV co-transmission and transmitted drug resistance mutations (DRMs) in newly HIV-diagnosed Los Angeles MSM.MethodsViral RNA was extracted from stored plasma samples from a Los Angeles cohort of newly diagnosed HIV-infected MSM with well-characterized substance use and sexual behavioral characteristics via computer-assisted self-interviewing surveys. Samples were screened for HCV by qPCR. HCV E1, E2, core, NS3 protease and NS5B polymerase and HIV-1 protease and reverse transcriptase regions were amplified and sequenced. Phylogenetic analysis was used to determine relatedness of HCV and HIV-1 isolates within the cohort and viral sequences were examined for DRMs.ResultsOf 185 newly HIV-diagnosed MSM, the majority (65 %) were of minority race/ethnicity and recently infected (57.8 %), with median age of 28.3 years. A minority (6.6 %) reported injection drug use (IDU), whereas 96 (52.8 %) reported recent substance use, primarily cannabis or stimulant use. High risk sexual behaviors included 132 (74.6 %) with unprotected receptive anal intercourse, 60 (33.3 %) with group sex, and 10 (5.7 %) with fisting. Forty-five (24.3 %) had acute gonorrhea or chlamydia infection. Only 3 (1.6 %) subjects had detectable HCV RNA. Amongst these subjects, HIV and HCV isolates were unrelated by phylogenetic analysis and none possessed clinically relevant NS3 or NS5B HCV DRMs.ConclusionsPrevalence of HCV co-infection was low and there was no evidence of HIV-HCV co-transmission in this cohort of relatively young, predominantly minority, newly HIV-diagnosed MSM, most with early HIV infection, with high rates of high risk sexual behaviors, STI, and non-IDU. The low HCV prevalence in a group with high-risk behaviors for non-IDU HCV acquisition suggests an opportune time for targeted HCV prevention measures.

HIV-1 Transmitted Drug Resistance Mutations in Newly Diagnosed Antiretroviral-Naive Patients in Turkey.

HIV-1 replication is rapid and highly error-prone. Transmission of a drug-resistant HIV-1 strain is possible and occurs within the HIV-1-infected population. In this study, we aimed to determine the prevalence of transmitted drug resistance mutations (TDRMs) in 1,306 newly diagnosed untreated HIV-1-infected patients from 21 cities across six regions of Turkey between 2010 and 2015. TDRMs were identified according to the criteria provided by the World Health Organization's 2009 list of surveillance drug resistance mutations. The HIV-1 TDRM prevalence was 10.1% (133/1,306) in Turkey. Primary drug resistance mutations (K65R, M184V) and thymidine analogue-associated mutations (TAMs) were evaluated together as nucleos(t)ide reverse transcriptase inhibitor (NRTI) mutations. NRTI TDRMs were found in 8.1% (107/1,306) of patients. However, TAMs were divided into three categories and M41L, L210W, and T215Y mutations were found for TAM1 in 97 (7.4%) patients, D67N, K70R, K219E/Q/N/R, T215F, and T215C/D/S mutations were detected for TAM2 in 52 (3.9%) patients, and M41L + K219N and M41L + T215C/D/S mutations were detected for the TAM1 + TAM2 profile in 22 (1.7%) patients, respectively. Nonnucleoside reverse transcriptase inhibitor-associated TDRMs were detected in 3.3% (44/1,306) of patients (L100I, K101E/P, K103N/S, V179F, Y188H/L/M, Y181I/C, and G190A/E/S) and TDRMs to protease inhibitors were detected in 2.3% (30/1,306) of patients (M46L, I50V, I54V, Q58E, L76V, V82A/C/L/T, N83D, I84V, and L90M). In conclusion, long-term and large-scale monitoring of regional levels of HIV-1 TDRMs informs treatment guidelines and provides feedback on the success of HIV-1 prevention and treatment efforts.

Molecular Characterization of the Human Immunodeficiency Virus Type 1 in Women and Their Vertically Infected Children.

Approximately 35 million people worldwide are infected with human immunodeficiency virus (HIV) around 3.2 million of whom are children under 15 years. Mother-to-child-transmission (MTCT) of HIV-1 accounts for 90% of all infections in children. Despite great advances in the prevention of MTCT in Brazil, children are still becoming infected. Samples from 19 HIV-1-infected families were collected. DNA was extracted and fragments from gag, pol, and env were amplified and sequenced directly. Phylogenetic reconstruction was performed. Drug resistance analyses were performed in pol and env sequences. We found 82.1% of subtype B and 17.9% of BF recombinants. A prevalence of 43.9% drug resistance-associated mutations in pol sequences was identified. Of the drug-naive children 33.3% presented at least one mutation related to protease inhibitor/nucleoside reverse transcriptase inhibitor/nonnucleoside reverse transcriptase inhibitor (PI/NRTI/NNRTI) resistance. The prevalence of transmitted drug resistance mutations was 4.9%. On env we found a low prevalence of HR1 (4.9%) and HR2 (14.6%) mutations.

Prevalence of Transmitted Drug Resistance Mutations in HIV-1-Infected Drug-Naive Patients from Urban and Suburban Regions of Kenya

HIV was first described in Kenya in 1984-1985. Currently, Kenya has an estimated HIV-1 prevalence of 6.2%. With the introduction of antiretroviral drugs, the survival of most HIV patients has been prolonged markedly. However, this is greatly threatened by increasing rates of antiretroviral dug resistance, which may eventually lead to suboptimal treatment outcomes. The objective of this study was to characterize currently occurring antiretroviral drug resistance mutations among drug-naive patients visiting two referral hospitals in Kenya. Using polymerase chain reaction, the HIV protease gene was amplified from blood samples of 63 study participants. The sequences were used to determine HIV-1 subtype and presence/prevalence of mutations associated with resistance to protease inhibitors. Finally, the protease gene was variably measured using Shannon entropy analysis. Analysis of frequency of HIV-1 subtypes revealed subtype A to be the predominant subtype, while the analysis of drug resistance mutations revealed the presence of four minor drug resistance mutations associated weakly with resistance to protease inhibitors. Among these mutations, L33I was the most prevalent mutation. Shannon entropy analysis revealed high genomic variability, especially in region spanning nucleotides 1-55, 113-170, and 205-240. This study warrants the need for dedicated efforts to improve compliance to antiretroviral therapy and reduce transmitted resistance rates, which will greatly ensure the therapeutic efficacy of antiretroviral drugs.

Clinical, epidemiological and treatment failure data among HIV-1 non-B-infected patients in the Spanish AIDS Research Network Cohort

IntroductionThe prevalence of HIV-1 non-B variants is increasing in Spain, showing a higher number of transmitted drug resistance mutations (TDR) since 2002. This study presents the features of non-B-infected patients enrolled in the cohort of antiretroviral treatment (ART) naïve HIV-infected patients included in the Research Network on HIV/AIDS (CoRIS). MethodsThe study includes a selected group of HIV-1 non-B-infected subjects from 670 subjects with pol sequences collected from 2004 to 2008 in the CoRIS cohort. Epidemiological-clinical-virological data were analyzed since cohort entry until October 2011, considering the presence or absence of treatment failure (TF). ResultsEighty two non-B infected subjects with known HIV-1 variants were selected from 2004 to 2008 in the CoRIS cohort, being mainly female, immigrants, infected by recombinant viruses, and by heterosexual route. They had an intermediate TDR rate (9.4%), a high rate of TF (25.6%), of losses to follow-up (35%), of coinfections (32.9%), and baseline CD4+ counts ≥350cells/mm3 (61.8%). Non-B subjects with TF showed higher rates of heterosexual infection (85.7% vs. 69.5%, p<0.05), tuberculosis (30.8% vs. 9.1%, p=0.10) and hepatitis C (23.8% vs. 13.9%, p=0.34) coinfections and lower rates of syphilis (0% vs. 21.9%, p<0.05), and had more frequently received first-line ART including protease inhibitors (PIs) than patients without TF (70% vs. 30%, p<0.05). Interestingly, infection with non-B variants reduced the risk of TDR to nucleoside reverse transcriptase inhibitors and increased the risk to PIs. ConclusionHIV-1 non-B-infected patients in Spain had a particular epidemiological and clinical profile that should be considered during their clinical management.

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

Morbidity and mortality among HIV-1-infected individuals has been dramatically reduced by the implementation of combinational antiretroviral therapy (ART). However, the efficiency of these therapies is compromised due to HIV-1 transmitted drug resistance mutations (TDRMs). We collected a total of 127 samples from ART-naïve HIV-infected individuals and sequenced the pol gene and analysed for drug resistance mutations using the Calibrated Population Resistance (CPR) tool in the Stanford database. All the 127 clinical samples (100%) were identified as HIV-1 subtype C. Based on the CPR tool, three strains (2.4%) had TDRMs, and these were K101E, Y181C and G190A. Our findings correlated well with the WHO surveys conducted in Asia, including India, which consistently reported<5% TDRM among the specific populations assessed. In countries like India, regular monitoring of TDRMs will provide better information for clinical practice improvement and policy making.

Systematic review to determine the prevalence of transmitted drug resistance mutations to rilpivirine in HIV-infected treatment-naive persons.

Transmitted drug resistance to antiretrovirals in HIV-1-infected individuals is rising in some regions and could compromise the effectiveness of first-line treatment. It is important to understand the prevalence of resistance to rilpivirine to inform treatment provision. A PUBMED/EMBASE search identified analyses of transmitted genotypic resistance to specific non-nucleoside reverse transcriptase inhibitor mutations worldwide. Patients were to be HIV-1-infected and antiretroviral-naive. Rilpivirine mutations assessed were: L100I, K101E/P, E138A/G/K/Q/R, V179L, Y181C/I/V, Y188L, H221Y, F227C and M230I/L. Additionally, frequency of resistance mutations were extracted and pooled by HIV subtype from the Stanford HIV drug resistance database. 138 eligible articles from 65 countries were identified (n=64,466). Among these 64,466 samples, 7 of the 9 genotypic rilpivirine mutations had a prevalence <0.1%. Two mutations were more prevalent: E138A/G/K/Q/R (0.7%, 95% CI 0.2, 1.3) and Y181C/I/V (0.3%, 95% CI 0.2, 0.4). Prevalence of E138 rilpivirine-related mutations varied between regions: highest in Latin America/Caribbean (3.6%, 95% CI 1.0, 7.6) and in Europe (3.2%, 95% CI 0.7, 6.9). Pooled results from the Stanford database (n=52,680) correlated with these findings indicating a low prevalence of 8/9 rilpivirine mutations (<0.1%), except for E138A/G/K/Q/R (2.9%, 95% CI 1.8, 4.4). Prevalence of the mutations at E138 varied significantly by HIV subtype and was highest for subtype-C (6.1%), subtype-F (5.1%) and subtype-A (3.3%). The prevalence of most transmitted rilpivirine-related HIV mutations is generally low in treatment-naive HIV-1-infected individuals (<0.1%). The prevalence of E138A/G/K/Q/R mutations is higher (0.7%) and varies according to geographical region and HIV subtype.

English

HIV treatment has been greatly impacted by transmitted resistance to antiretrovirals (ARV). Several studies have documented resistance in naive individuals and estimates of transmitted drug resistance mutations range from <5% to as high as 25%. Washington, D.C. has one of the highest human immunodeficiency virus (HIV) prevalence rates in the United States (3.2% in 2009), but local data regarding the frequency of major mutations and antiretroviral (ARV) resistance has been limited. Medical records of HIV positive, ARV-naive adults at two facilities in Washington, D.C., The George Washington University Medical Center and the Veterans Affairs Medical Center, were retrospectively analyzed in subjects who had genotypic resistance testing from 2007 to 2010. Of 407 ARV-naive patients, at least one transmitted drug resistance mutation was detected in 17% of our patients, with non-nucleoside reverse transcriptase (NNRTI) mutations observed in 15%. Among patients with at least one reverse transcriptase (RT) or major protease region (Pr) resistance mutation, 85% had resistance against a single ARV class. Dual and triple class resistance mutations were seen in 8 patients (2%) and 3 patients (0.7%), respectively. Most of the multiple class resistance was seen in 2010. A gradual increase in NNRTI resistance was noted during 2008 to 2010. Our prevalence of transmitted RT, major Pr mutations (17.4%) and ARV resistance (8.6%) were high but similar to rates reported by others within the United States. Given the high HIV prevalence in the District of Columbia, this has important implications for treatment of these ARV-naive patients. Key words: HIV, Washington D.C., naive to antiretrovirals, transmitted drug resistance, transmitted drug resistance mutations, antiretroviral mutations.

Prevalence of HIV-1 Subtypes and Drug Resistance-Associated Mutations in HIV-1-Positive Treatment-Naive Pregnant Women in Pointe Noire, Republic of the Congo (Kento-Mwana Project).

The Kento-Mwana project was carried out in Pointe Noire, Republic of the Congo, to prevent mother-to-child HIV-1 transmission. To determine the prevalence of different subtypes and transmitted drug resistance-associated mutations, 95 plasma samples were collected at baseline from HIV-1-positive naive pregnant women enrolled in the project during the years 2005-2008. Full protease and partial reverse transcriptase sequencing was performed and 68/95 (71.6%) samples were successfully sequenced. Major mutations to nucleoside reverse transcriptase inhibitors, nonnucleoside reverse transcriptase inhibitors, and protease inhibitors were detected in 4/68 (5.9%), 3/68 (4.4%), and 2/68 (2.9%) samples, respectively. Phylogenetic analysis of HIV-1 isolates showed a high prevalence of unique recombinant forms (24/68, 35%), followed by CRF45_cpx (7/68, 10.3%) and subsubtype A3 and subtype G (6/68 each, 8.8%). Although the prevalence of transmitted drug resistance mutations appears to be currently limited, baseline HIV-1 genotyping is highly advisable in conjunction with antiretroviral therapy scale-up in resource-limited settings to optimize treatment and prevent perinatal transmission.

Evidence of Self-Sustaining Drug Resistant HIV-1 Lineages Among Untreated Patients in the United Kingdom.

About 10% of new diagnoses of subtype B human immunodeficiency virus type 1 (HIV-1) in the United Kingdom are with viruses showing transmitted drug resistance (TDR). However, there is discordance between the mutation patterns observed in HIV-infected patients failing therapy and those seen in TDR. We extracted all subtype B HIV-1 pol gene sequences from treatment-naive patients within the United Kingdom HIV Drug Resistance Database sampled between 1997 and 2011 and carrying the most common protease inhibitors, nonnucleoside and nucleotide reverse transcriptase inhibitors TDR mutations, namely, L90M, K103N, and T215Y/F/rev, respectively (n = 1140). Transmission clusters (n ≥ 2 sequences) were identified by maximum-likelihood phylogeny using a genetic distance cutoff of ≤ 1.5%. The time of origin and the basic reproductive number (R0) of clusters were estimated by Bayesian methods. T215rev was present alone in 47% of the sequences (n = 540), K103N in 31% (n = 359), and L90M in 10% (n = 109). The remaining sequences contained T215Y or combinations of L90M, K103N, and T215rev. Fifty-five percent (n = 624) of the sequences formed highly supported transmission clusters (n = 193) containing between 2 and 15 sequences. The time of origin of 10 large clusters (≥ 8 sequences) was estimated to be between 2000 (1999-2002; 95% highest posterior density [HPD]) and 2006 (2005-2007; 95% HPD). The oldest cluster had persisted for nearly 8 years. All 10 clusters had R0s ranging from 1.3 (0.4-2.5; 95% HPD) to 2.8 (0.6-6.5; 95% HPD). A high proportion of the most common TDR in subtype B infections in the United Kingdom is derived by onward transmission from treatment-naive patients.

Transmitted Drug Resistance Mutations in Antiretroviral-Naïve Injection Drug Users with Chronic HIV-1 Infection in Iran.

The growing incidence and transmission of drug resistant HIV-1 strains due to widespread use of antiretroviral therapy (ART) can jeopardize the success of first-line ART. While there is a known moderate prevalence of transmitted drug resistance (TDR) among newly infected Iranians, no data exist about the rate of these primary resistance mutations among the ART-naïve, chronically infected individuals who are, in fact, the main candidates for ART initiation. To address this issue, we collected blood samples from 40 ART-naïve injection drug-users (IDUs) with chronic HIV-1 infection (seroconversion time ranging from 2 to 9 years) living in Sanandaj, Iran, followed by sequencing of the protease and reverse-transcriptase regions from their HIV-1 genome. Phylogenetic analyses of the sequenced regions revealed that all samples were CRF35_AD. Transmitted resistance mutations were interpreted as surveillance drug-resistant mutations (SDRMs) based on the world health organization (WHO) algorithm. The frequency of SDRMs to any class of antiretroviral drugs was 15%, which included mutations to nucleoside reverse transcriptase inhibitors (NRTIs, 10%), with M41L and M184V as the most common (5%), and non-nucleoside reverse transcriptase inhibitors (NNRTIs, 5%), with K103N as the only detected mutation (5%). Although not in the WHO SDRMs list, several minor protease inhibitor resistant mutations listed in the International Antiviral Society-USA panel were identified, of which M36I, H69K, L89M/V/I (each one 100%) and K20R/T (92.5%) can be considered as polymorphic signatures for CRF35_AD.The relatively high rate of TDR mutations in our study raises concerns about the risk of treatment failure in chronically infected IDUs of Sanandaj city. These results suggest that routine resistance testing should be considered before the therapy initiation in this area. Additional surveillance studies are required to generalize this deduction to other cities of Iran.

Transmitted Drug Resistance Among Recently Diagnosed Adults and Children in São Paulo, Brazil

Transmitted drug resistance mutations (TDRM) have been a constant threat to treatment efficacy. We evaluated TDRM in plasma RNA of 217 antiretroviral therapy-naive patients from sites in the São Paulo metropolitan area, collected from 2012 to 2014. The partial HIV-1 polymerase region was sequenced using Big Dye terminators at an ABI 3130 Genetic Analyzer. TDRM was defined according to the Stanford database calibrated population resistance (CPR v.6.0), but other drug resistance mutations (DRM) considered at the IAS list (IAS, 2014) and at the Stanford HIV Database Genotyping Resistance Interpretation (GRI-HIVdb) were also described. Out of 78% (170/217) of patients with information on the time of diagnosis, most (83%, 141/170) had been recently diagnosed, with the first positive HIV serology at a median of 58 days (IQR 18-184). Subtype B predominated (70%), followed by subtype F (10%), BF (7.5%), C (7.5%), and BC (5%). TDRMs were observed in 9.2% (20/217, CI 95% 5.9% to 13.6%), mostly (5.2%) to nonnucleoside reverse transcriptase inhibitor (NNRTI) antiretroviral class. Among children and adolescents, only a single patient showed TDRMs. Additional non-CPR mutations were observed: 11.5% (25/217) according to IAS or 4.6% (10/217) according to GRI-HIVdb. Overall, 23.5% (51/217) of the cases had one or more DRM identified. TDRM prevalence differed significantly among some sites. These trends deserve continuous and systematic surveillance, especially with the new policies of treatment as prevention being implemented in the country.

Genetic Characteristics of CRF01_AE Among Newly Diagnosed HIV-1-Infected 16- to 25-Year Olds in 3 Geographic Regions of Guangxi, China.

The aim of this study was to analyze the distribution of clusters and drug resistance of CRF01_AE among newly diagnosed, treatment-naïve HIV-infected teenagers and young adults in 3 major HIV-affected geographic regions of Guangxi Province, including the cities of Hezhou, Liuzhou, and Nanning. Samples were sequentially collected from newly diagnosed HIV-infected 16- to 25-year olds in these 3 regions from 2009 to 2013. The viral genome was extracted, and the partial pol gene was amplified and sequenced. Phylogenetic analyses were used to determine HIV-1 subtypes and CRF01_AE clusters. Transmitted drug resistance (TDR) mutations were identified using the 2009 WHO list of TDR mutations. A total of 216 sequences were obtained from CRF01_AE strains, which accounted for 83.1% of the 260 genotyped samples, of which 36 were from Hezhou, 147 from Liuzhou, and 33 in Nanning. Most (83.3%, 180/216) were from heterosexuals, followed by injection drug users (5.6%), homosexuals (4.2%), and unknown risk group (6.9%). Based on phylogenetic analyses by the maximum likelihood method, 5 distinct clusters (cluster 1-5) were identified with 213 (98.6%) sequences, whereas 3 (1.4%) sequences were ungrouped. In Hezhou, 88.9% (32/36) of CRF01_AE infections were caused by cluster 2, and 11.1% (4/36) were caused by cluster 1. In Liuzhou, 83.0% (122/147) of the CRF01_AE strains were found in cluster 1, 11.6% (17/147) from cluster 2, 1.4% (2/147) from cluster 3, 2.7% (4/147) from cluster 4, and 0.7% (1/147) from cluster 5. The distribution of CRF01_AE clusters was more even in Nanning than it was in the other 2 regions, with 18.2% (6/33) from cluster 1, 36.3% (12/33) from cluster 2, 9.1% (3/33) from cluster 3, 18.2% (6/33) from cluster 4, and 12.1% (4/33) from cluster 5. The most frequent TDR mutations were M46I (2) in the protease region and Y181C (2) from the reverse transcriptase fragment. Clusters 1 and 2 of CRF01_AE strains were prevalent in Liuzhou and Hezhou, respectively. However, multiple CRF01_AE clusters existed in Nanning. This can be partially explained by the high mobility of laborers in Nanning, the capital city of Guangxi. The prevalence of TDR was low.

Trends on epidemiological, virological, and clinical features among newly diagnosed HIV-1 persons in Northwest Spain over the last 10 years.

To describe temporal trend and characteristics of newly HIV-diagnosed patients in a medical care area in Northwest Spain over the last 10 years. All newly diagnosed patients for HIV-infection from 2004 to 2013 at a reference medical care area in Northwest of Spain were identified. Epidemiological, virological, immunological, and clinical data, as well as HIV genotype and drug resistance information were recorded. A total of 565 newly HIV-diagnosed patients were identified. The number of new cases increased in the last 5 years (66 cases/year). Overall, 53.1% had a median CD4 counts < 350 cells/µl and 33.6% had an AIDS defining criteria. Non-B variants were found in 34.4% of patients being subtype F (25.8%) the most common non-B subtype. The rate of transmitted drug resistance (TDR) over the study period was 3.7%, but a decreased to 2.6% was observed in the last 5 years. The most prevalent TDR mutations were: T215 revertants (1.5%), K219QENR (1.2%), for NRTIs; K103N (1.9%), for NNRTIs; L90M (0.3%), for PIs. Overall, 73.2% of patients started antiretroviral treatment and 9.9% of patients died during follow-up. The number of newly HIV diagnosed patients increased since year 2009. There is a high prevalence of late diagnosis (53%) and 33% had an AIDS defining criteria. Interestingly, the most prevalent non-B subtype in our population was F (25.8%). These findings support the need to facilitate the access for HIV testing to reduce the rate of late HIV diagnosis, improve the clinical outcome and prevent HIV transmission.

Global HIV-1 transmitted drug resistance in the INSIGHT Strategic Timing of AntiRetroviral Treatment (START) trial.

HIV-1 transmitted drug resistance (TDR) in treatment-naïve individuals is a well-described phenomenon. Baseline genotypic resistance testing is considered standard of care in most developed areas of the world. The aim of this analysis was to characterize HIV-1 TDR and the use of resistance testing in START trial participants. In the Strategic Timing of AntiRetroviral Treatment (START) trial, baseline genotypic resistance testing results were collected at study entry and analysed centrally to determine the prevalence of TDR in the study population. Resistance was based on a modified 2009 World Health Organization definition to reflect newer resistance mutations. Baseline resistance testing was available in 1946 study participants. Higher rates of testing occurred in Europe (86.7%), the USA (81.3%) and Australia (89.9%) as compared with Asia (22.2%), South America (1.8%) and Africa (0.1%). The overall prevalence of TDR was 10.1%, more commonly to nonnucleoside reverse transcriptase inhibitors (4.5%) and nucleoside reverse transcriptase inhibitors (4%) compared with protease inhibitors (2.8%). The most frequent TDR mutations observed were M41L, D67N/G/E, T215F/Y/I/S/C/D/E/V/N, 219Q/E/N/R, K103N/S, and G190A/S/E in reverse transcriptase, and M46I/L and L90M in protease. By country, the prevalence of TDR was highest in Australia (17.5%), France (16.7%), the USA (12.6%) and Spain (12.6%). No participant characteristics were identified as predictors of the presence of TDR. START participants enrolled in resource-rich areas of the world were more likely to have baseline resistance testing. In Europe, the USA and Australia, TDR prevalence rates varied by country.

HIV-1 transmitted drug resistance mutations among antiretroviral therapy-Naïve individuals in Surabaya, Indonesia.

BackgroundThe emergence of transmitted drug resistance (TDR) compromises the effect of antiretroviral therapy (ART), resulting in treatment failure of human immunodeficiency virus (HIV) disease. Although more than a decade has passed since ART was introduced into Indonesia, information on TDR is limited. Here, a genotypic study of TDR among ART-naïve individuals was conducted in Surabaya, Indonesia.MethodHIV-1 seropositive participants were recruited from the communities of commercial sex workers and intravenous drug users as well as from the university teaching hospital in Surabaya. Protease (PR) and reverse transcriptase (RT) genes were sequenced in order to conduct HIV-1 subtyping and phylogenetic analysis and to detect TDR. TDR was defined as the presence of at least one surveillance drug resistance mutation on the WHO list or major drug resistance mutations in the International AIDS Society-USA panel.ResultFifty two and 47 of the PR and RT genes, respectively, were successfully sequenced in the 58 samples. HIV-1 subtyping revealed that 86.3% (50/58) of the sequenced samples were classified as CRF01_AE, 8.6% as subtype B, 3.4% as B/CRF01_AE, and 1.7% as A/G/CRF01_AE. TDR of PR inhibitors was not detected in this study. In contrast, TDR of RT inhibitors was detected in 4.3% (2/47) of samples. In addition, minor drug resistance mutations were detected in 98.1% (51/52) and 12.8% (6/47) of PR and RT genes, respectively.ConclusionThis study clarified the predominance of the CRF01_AE strain in Surabaya, Indonesia. The prevalence of TDR was below 5%, indicating that the currently available first-line regimen is still effective in Surabaya. However, the prevalence might be underestimated since we detected only major population of HIV-1 in individuals. Therefore, continuous surveillance is required in order to detect the emergence of TDR in the early phase.Electronic supplementary materialThe online version of this article (doi:10.1186/s12981-015-0046-y) contains supplementary material, which is available to authorized users.

Low HIV-1 transmitted drug resistance in Bulgaria against a background of high clade diversity.

To determine transmitted drug resistance (TDR) and HIV-1 genetic diversity in Bulgaria. The prevalence of TDR and HIV-1 subtypes was determined in 305/1446 (21.1%) persons newly diagnosed with HIV/AIDS from 1988 to 2011. TDR mutations (TDRMs) in protease and reverse transcriptase were defined using the WHO HIV drug mutation list. Phylogenetic analysis was used to infer polymerase (pol) genotype. TDRMs were found in 16/305 (5.2%) persons, 11 (3.6%) with resistance to NRTIs, 5 (1.6%) with resistance to NNRTIs and 3 (0.9%) with resistance to PIs. Dual-class TDRMs were found in three (1.0%) patients and one statistically supported cluster of TDRMs comprising two individuals with subtype B infection. TDRMs were found in 10 heterosexuals, 4 MSM and two intravenous drug users. Phylogenetic analyses identified high HIV-1 diversity consisting of mostly subtype B (44.6%), subtype C (3.3%), sub-subtype A1 (2.6%), sub-subtype F1 (2.3%), sub-subtype A-like (3.6%), subtype G (0.3%), CRF14_BG (1.6%), CRF05_DF (1.3%), CRF03_AB (0.3%) and unique recombinant forms (1.3%). We found a low prevalence of TDR against a background of high HIV-1 genetic diversity among antiretroviral-naive patients in Bulgaria. Our results provide baseline data on TDR and support continued surveillance of high-risk populations in Bulgaria to better target treatment and prevention efforts.

Assessing the Paradox Between Transmitted and Acquired HIV Type 1 Drug Resistance Mutations in the Swiss HIV Cohort Study From 1998 to 2012

Transmitted human immunodeficiency virus type 1 (HIV) drug resistance (TDR) mutations are transmitted from nonresponding patients (defined as patients with no initial response to treatment and those with an initial response for whom treatment later failed) or from patients who are naive to treatment. Although the prevalence of drug resistance in patients who are not responding to treatment has declined in developed countries, the prevalence of TDR mutations has not. Mechanisms causing this paradox are poorly explored. We included recently infected, treatment-naive patients with genotypic resistance tests performed ≤ 1 year after infection and before 2013. Potential risk factors for TDR mutations were analyzed using logistic regression. The association between the prevalence of TDR mutations and population viral load (PVL) among treated patients during 1997-2011 was estimated with Poisson regression for all TDR mutations and individually for the most frequent resistance mutations against each drug class (ie, M184V/L90M/K103N). We included 2421 recently infected, treatment-naive patients and 5399 patients with no response to treatment. The prevalence of TDR mutations fluctuated considerably over time. Two opposing developments could explain these fluctuations: generally continuous increases in the prevalence of TDR mutations (odds ratio, 1.13; P = .010), punctuated by sharp decreases in the prevalence when new drug classes were introduced. Overall, the prevalence of TDR mutations increased with decreasing PVL (rate ratio [RR], 0.91 per 1000 decrease in PVL; P = .033). Additionally, we observed that the transmitted high-fitness-cost mutation M184V was positively associated with the PVL of nonresponding patients carrying M184V (RR, 1.50 per 100 increase in PVL; P < .001). Such association was absent for K103N (RR, 1.00 per 100 increase in PVL; P = .99) and negative for L90M (RR, 0.75 per 100 increase in PVL; P = .022). Transmission of antiretroviral drug resistance is temporarily reduced by the introduction of new drug classes and driven by nonresponding and treatment-naive patients. These findings suggest a continuous need for new drugs, early detection/treatment of HIV-1 infection.

Lack of resistance to integrase inhibitors among antiretroviral-naive subjects with primary HIV-1 infection, 2007-2013.

US guidelines recommend genotyping for persons newly diagnosed with HIV infection to identify transmitted drug resistance mutations associated with decreased susceptibility to nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors and protease inhibitors. To date, testing for integrase strand transfer inhibitor (INSTI) mutations has not been routinely recommended. We aimed to evaluate the prevalence of transmitted INSTI mutations among persons with primary HIV-1 infection in Seattle, WA, USA. Persons with primary HIV-1 infection have enrolled in an observational cohort at the University of Washington Primary Infection Clinic since 1992. We performed a retrospective analysis of plasma specimens collected prospectively from the 82 antiretroviral-naive subjects who were enrolled from 2007-2013, after FDA-approval of the first INSTI. Resistance testing was performed by consensus sequencing. Specimens for analysis had been obtained a median of 24 (IQR 18-41, range 8-108) days after the estimated date of HIV-1 infection. All subjects were infected with HIV-1 subtype B except for one subject infected with subtype C. Consensus sequencing identified no subjects with major INSTI mutations (T66I, E92Q, G140S, Y143C/H/R, S147G, Q148H/K/R, N155H). Using exact binomial CIs, the upper bound of the 95% CI was 4.4%. Although our sample size was small, this study does not support the need at this time to evaluate integrase mutations as part of routine consensus sequencing among persons newly diagnosed with HIV-1 infection. However, it is likely that the prevalence of transmitted INSTI mutations may increase with the recent commercial introduction of additional INSTIs and presumably greater INSTI use among persons living with HIV-1.