Different trends of transmitted HIV-1 drug resistance in Madrid, Spain, among risk groups in the last decade

Transmitted drug resistance to antiretroviral drugs in Spain during the period 2019-2021

To evaluate the prevalence of transmitted drug resistance (TDR) to nucleoside and nonnucleoside reverse transcriptase inhibitors (NRTI, NNRTI), protease inhibitors (PI), and integrase strand transfer inhibitors (INSTI) in Spain during the period 2019-2021, as well as to evaluate transmitted clinically relevant resistance (TCRR) to antiretroviral drugs. Reverse transcriptase (RT), protease (Pro), and Integrase (IN) sequences from 1824 PLWH (people living with HIV) were studied. To evaluate TDR we investigated the prevalence of surveillance drug resistance mutations (SDRM). To evaluate TCRR (any resistance level ≥ 3), and for HIV subtyping we used the Stanford v.9.4.1 HIVDB Algorithm and an in-depth phylogenetic analysis. The prevalence of NRTI SDRMs was 3.8% (95% CI, 2.8%-4.6%), 6.1% (95% CI, 5.0%-7.3%) for NNRTI, 0.9% (95% CI, 0.5%-1.4%) for PI, and 0.2% (95% CI, 0.0%-0.9%) for INSTI. The prevalence of TCRR to NRTI was 2.1% (95% CI, 1.5%-2.9%), 11.8% for NNRTI, (95% CI, 10.3%-13.5%), 0.2% (95% CI, 0.1%-0.6%) for PI, and 2.5% (95% CI, 1.5%-4.1%) for INSTI. Most of the patients were infected by subtype B (79.8%), while the majority of non-Bs were CRF02_AG (n = 109, 6%). The prevalence of INSTI and PI resistance in Spain during the period 2019-2021 is low, while NRTI resistance is moderate, and NNRTI resistance is the highest. Our results support the use of integrase inhibitors as first-line treatment in Spain. Our findings highlight the importance of ongoing surveillance of TDR to antiretroviral drugs in PLWH particularly with regard to first-line antiretroviral therapy.

Transmitted HIV-1 is more virulent in heterosexual individuals than men-who-have-sex-with-men

Transmission bottlenecks introduce selection pressures on HIV-1 that vary with the mode of transmission. Recent studies on small cohorts have suggested that stronger selection pressures lead to fitter transmitted/founder (T/F) strains. Manifestations of this selection bias at the population level have remained elusive. Here, we analysed early CD4 cell count measurements reported from ∼340,000 infected heterosexual individuals (HET) and men-who-have-sex-with-men (MSM), across geographies, ethnicities and calendar years. The reduction in CD4 counts early in infection is reflective of the virulence of T/F strains. MSM and HET use predominant modes of transmission, namely, anal and penile-vaginal, with among the largest differences in the selection pressures at transmission across modes. Further, in most geographies, the groups show little inter-mixing, allowing for the differential selection bias to be sustained and amplified. We found that the early reduction in CD4 counts was consistently greater in HET than MSM (P<0.05). To account for inherent variations in baseline CD4 counts, we constructed a metric to quantify the extent of progression to AIDS as the ratio of the reduction in measured CD4 counts from baseline and the reduction associated with AIDS. We found that this progression corresponding to the early CD4 measurements was ∼68% for MSM and ∼87% for HET on average (P<10⁻⁴; Cohen’s d, d_s = 0.36), reflecting the more severe disease caused by T/F strains in HET than MSM at the population level. Interestingly, the set-point viral load was not different between the groups (d_s<0.12), suggesting that MSM were more tolerant and not more resistant to their T/F strains than HET. This difference remained when we controlled for confounding factors using multivariable regression. We concluded that the different selection pressures at transmission have resulted in more virulent T/F strains in HET than MSM. These findings have implications for our understanding of HIV-1 pathogenesis, evolution, and epidemiology.

HIV-1 encounters a key bottleneck at the time of its transmission from one individual to another. This transmission bottleneck can differ between modes of transmission. The stronger this bottleneck is, the more fit the virus has to be to be successfully transmitted. Accordingly, the transmitted/founder (T/F) strains of HIV-1 may have different fitness in risk groups that use different modes of transmission. While studies on small cohorts do support this notion, observations of the manifestations of this differential selection bias at the population level have been lacking. Here, we examined reported early CD4 count measurements from ∼340,000 HET and MSM, across geographies, ethnicities, and calendar years. Early CD4 counts are a measure of the severity of the infection due to T/F strains. HET and MSM transmit predominantly via penile-vaginal and anal modes, respectively, and do not inter-mix significantly. Remarkably, we found that HET consistently had lower early CD4 counts than MSM. This difference could not be attributed to potential confounding factors, such as set-point viral load. The difference thus provided evidence that T/F strains had evolved to be more virulent in HET than MSM at the population level. Intervention strategies may benefit from accounting for this difference between risk groups.

HIV drug resistance in persons who inject drugs enrolled in an HIV prevention trial in Indonesia, Ukraine, and Vietnam: HPTN 074

BACKGROUND

Persons who inject drugs (PWID) have high HIV incidence and prevalence, and may have limited access to antiretroviral therapy (ART) in some settings. We evaluated HIV drug resistance in PWID in a randomized clinical trial (HPTN 074). The study intervention included ART at any CD4 cell count with enhanced support for ART and substance use treatment.

METHODS

HPTN 074 enrolled HIV-infected PWID (index participants) with viral loads ≥1,000 copies/mL and their HIV-uninfected injection-network partners in Indonesia, Ukraine, and Vietnam; the study limited enrollment of people who reported being on ART. HIV drug resistance testing and antiretroviral (ARV) drug testing were performed using samples collected from index participants at study enrollment.

RESULTS

Fifty-four (12.0%) of 449 participants had HIV drug resistance; 29 (53.7%) of the 54 participants had multi-class resistance. Prevalence of resistance varied by study site and was associated with self-report of prior or current ART, detection of ARV drugs, and a history of incarceration. Resistance was detected in 10 (5.6%) of 177 newly diagnosed participants. Participants with resistance at enrollment were less likely to be virally suppressed after 52 weeks of follow-up, independent of study arm.

CONCLUSIONS

In HPTN 074, many of the enrolled index participants had HIV drug resistance and more than half of those had multi-class resistance. Some newly-diagnosed participants had resistance, suggesting that they may have been infected with drug-resistant HIV strains. Behavioral and geographic factors were associated with baseline resistance. Baseline resistance was associated with reduced viral suppression during study follow-up. These findings indicate the need for enhanced HIV care in this high-risk population to achieve sustained viral suppression on ART.

Analysis of transmitted HIV drug resistance from 2005 to 2015 in Victoria, Australia: a comparison of the old and the new

Background Baseline genotyping is part of standard-of-care treatment. It reveals that transmitted drug resistance (TDR) continues to be important for the management of HIV infection. Attention is typically focused on determining whether resistance to the protease inhibitors (PI) and reverse transcriptase inhibitors (RTI) occurs. However, the increasing use of integrase inhibitors (INIs) raises a concern that TDR to this class of antiretroviral drug may also occur.

METHODS

PI and RTI drug resistance genotyping was performed on blood samples collected between 2005 and 2015 from 772 treatment-naïve Victorian patients infected with HIV within the previous 12 months. Integrase genotyping was performed on 461 of the 485 patient samples collected between 2010 and 2015.

RESULTS

In the period 2005-10, 39 of 343 patients (11.4%) had at least one PI- or RTI-associated mutation, compared with 34 of 429 (7.9%) during the period 2011-15. Compared with 2005-10, during 2011-15 there was a significant decline in the prevalence of the non-nucleoside-associated mutation K103N and the nucleoside-associated mutations at codons M41 and T215. One patient was detected with a major INI resistance mutation, namely G118R. However, this mutation is rare and its effect on susceptibility is unclear. A small number of patients (n=12) was infected with HIV containing accessory resistance mutations in the integrase gene.

CONCLUSIONS

The lack of transmitted resistance to INIs is consistent with a low level of resistance to this class of drugs in the treated population. However, continued surveillance in the newly infected population is warranted as the use of INIs increases.

Continued propagation of the CRF19_cpx variant among HIV-positive MSM patients in Spain

Objectives

The HIV-1 CRF19_cpx genetic form has been recently associated with greater pathogenicity. We used CoRIS, a national cohort of 31 reference hospitals in Spain, to investigate the current epidemiological situation of this variant in Spain.

Patients and methods

We analysed 4734 naive HIV-1-positive patients diagnosed during the 2007-15 period with an available pol gene sequence in the CoRIS resistance database. HIV-1 CRF19_cpx was ascribed through REGA3.0 and confirmed by a phylogenetic analysis. We analysed the presence of the transmission clusters of HIV-1 CRF19_cpx by maximum likelihood [with the randomized accelerated maximum likelihood (RAxML) program] and the time to the most recent common ancestor using Bayesian inference (BEAST, v. 1.7.5).

Results

Nineteen patients were infected with CRF19_cpx: all were male, they had a mean age of 42.9 years (95% CI: 36.4-52.5 years), the majority were MSM [n = 18 (95%)] and of Spanish nationality [n = 16 (84.2%)] and they had high CD4+ T cell counts (∼415 cells/mm3). Fifteen patients were grouped into four different transmission clusters: two clusters (two patients each) grouped the patients from Valencia and another cluster grouped one patient from Madrid and another from Seville. We found a larger cluster that grouped nine patients from southern Spain (Malaga and Seville), of which six presented mutation G190A. We estimated the origin of all the transmission clusters to take place between 2009 and 2010.

Conclusions

We demonstrate that this variant has spread in Spain in recent years among young HIV-positive MSM and we note a recent expansion in southern Spain in patients who carry mutation G190A. We alert healthcare managers to enhance preventive measures to prevent the continuous spread of HIV-1 CRF19_cpx.

Prevalence of Transmitted HIV drug resistance in antiretroviral treatment naïve newly diagnosed individuals in China

To investigate the prevalence and temporal trend of transmitted drug resistance (TDR), a nationwide cross-sectional survey was conducted among 5627 ART naïve newly diagnosed HIV-infected individuals in 2015 in China. Totally 4704 partial pol sequences were obtained. Among them, the most common HIV-1 circulating recombinant form (CRF) or subtype was CRF01_AE (39.0%), followed by CRF07_BC (35.6%), CRF08_BC (8.9%), and subtype B (5.5%). TDR mutations were found in 3.6% of the cases, with 1.1% harboring TDR to protease inhibitors (PIs), 1.3% having TDR to nucleoside reverse transcriptase inhibitors (NRTIs), and 1.6% to non-nucleoside reverse transcriptase inhibitors (NNRTIs). No significant difference was found in the prevalence of TDR, as compared with the results of another nationwide survey performed among ART naïve HIV-infected people in between 2004 and 2005, except in the 16-25 year-old group. In addition, four drug-resistant transmission clusters were identified in phylogenetic trees, accounting for 6.2% (9/145) of the individuals with TDR. Although the rate of TDR remained relatively low in the past 10 years in China, surveillance is still needed to monitor the trend of TDR and to optimize the first-line regimens.

Dynamics and phylogenetic relationships of HIV-1 transmitted drug resistance according to subtype in Italy over the years 2000-14

Background

Transmitted drug-resistance (TDR) remains a critical aspect for the management of HIV-1-infected individuals. Thus, studying the dynamics of TDR is crucial to optimize HIV care.

Methods

In total, 4323 HIV-1 protease/reverse-transcriptase sequences from drug-naive individuals diagnosed in north and central Italy between 2000 and 2014 were analysed. TDR was evaluated over time. Maximum-likelihood and Bayesian phylogenetic trees with bootstrap and Bayesian-probability supports defined transmission clusters.

Results

Most individuals were males (80.2%) and Italian (72.1%), with a median (IQR) age of 37 (30-45) years. MSM accounted for 42.2% of cases, followed by heterosexuals (36.4%). Non-B subtype infections accounted for 30.8% of the overall population and increased over time (<2005-14: 19.5%-38.5%, P < 0.0001), particularly among Italians (<2005-14: 6.5%-28.8%, P < 0.0001). TDR prevalence was 8.8% and increased over time in non-B subtypes (<2005-14: 2%-7.1%, P = 0.018). Overall, 467 transmission clusters (involving 1207 individuals; 27.9%) were identified. The prevalence of individuals grouping in transmission clusters increased over time in both B (<2005-14: 12.9%-33.5%, P = 0.001) and non-B subtypes (<2005-14: 18.4%-41.9%, P = 0.006). TDR transmission clusters were 13.3% within the overall cluster observed and dramatically increased in recent years (<2005-14: 14.3%-35.5%, P = 0.005). This recent increase was mainly due to non-B subtype-infected individuals, who were also more frequently involved in large transmission clusters than those infected with a B subtype [median number of individuals in transmission clusters: 7 (IQR 6-19) versus 4 (3-4), P = 0.047].

Conclusions

The epidemiology of HIV transmission changed greatly over time; the increasing number of transmission clusters (sometimes with drug resistance) shows that detection and proper treatment of the multi-transmitters is a major target for controlling HIV spread.

Molecular evolution methods to study HIV-1 epidemics

Nucleotide sequences of HIV isolates are obtained routinely to evaluate the presence of resistance mutations to antiretroviral drugs. But, beyond their clinical use, these and other viral sequences include a wealth of information that can be used to better understand and characterize the epidemiology of HIV in relevant populations. In this review, we provide a brief overview of the main methods used to analyze HIV sequences, the data bases where reference sequences can be obtained, and some caveats about the possible applications for public health of these analyses, along with some considerations about their limitations and correct usage to derive robust and reliable conclusions.

The molecular epidemiology of HIV-1 in the Comunidad Valenciana (Spain): analysis of transmission clusters

HIV infections are still a very serious concern for public heath worldwide. We have applied molecular evolution methods to study the HIV-1 epidemics in the Comunidad Valenciana (CV, Spain) from a public health surveillance perspective. For this, we analysed 1804 HIV-1 sequences comprising protease and reverse transcriptase (PR/RT) coding regions, sampled between 2004 and 2014. These sequences were subtyped and subjected to phylogenetic analyses in order to detect transmission clusters. In addition, univariate and multinomial comparisons were performed to detect epidemiological differences between HIV-1 subtypes, and risk groups. The HIV epidemic in the CV is dominated by subtype B infections among local men who have sex with men (MSM). 270 transmission clusters were identified (>57% of the dataset), 12 of which included ≥10 patients; 11 of subtype B (9 affecting MSMs) and one (n = 21) of CRF14, affecting predominately intravenous drug users (IDUs). Dated phylogenies revealed these large clusters to have originated from the mid-80s to the early 00 s. Subtype B is more likely to form transmission clusters than non-B variants and MSMs to cluster than other risk groups. Multinomial analyses revealed an association between non-B variants, which are not established in the local population yet, and different foreign groups.

Epidemiological trends of HIV-1 infection in blood donors from Catalonia, Spain (2005-2014)

BACKGROUND

Human immunodeficiency virus 1 (HIV-1) subtype B is predominant in Spain. However, the recent arrival of immigrant populations has increased the prevalence of non-B subtypes and circulating recombinant forms. The objective of this study was to determine the prevalence of HIV-1 subtypes and transmitted drug-resistance mutations in blood donors from the Catalonian region (northeastern Spain).

STUDY DESIGN AND METHODS

HIV-1-positive blood donors identified in Catalonia from 2005 to 2014 were included. Demographic variables and risk factors for HIV-1 acquisition were recorded. HIV-1 subtyping was carried out by HIV-1 DNA polymerase region sequencing, and phylogenetic analyses were performed using the neighbor-joining method.

RESULTS

During the study period, 2.8 million blood donations were screened, and 214 HIV-1-positive donors were identified, yielding an overall prevalence of 7.7 per 100,000 donations (89% men; mean age, 34 ± 10 years). Most HIV-1-positive donors were native to Spain (81%), and 61% were regular blood donors. When risk factors were known, 62% reportedly were men who had sex with men. HIV-1 subtyping was possible in 176 HIV-1-positive individuals: 143 (81%) had HIV-1 subtype B, and 33 (19%) had non-B subtypes. Most HIV-1 non-B subtypes were circulating recombinant forms (n = 20; 61%). Factors associated with HIV-1 subtype B were male sex (p = 0.007) and men who had sex with men (p < 0.001). The overall prevalence of transmitted drug-resistance mutations was 14%.

CONCLUSION

Non-B subtypes, circulating recombinant forms, and transmitted drug-resistance mutation sequences circulate among HIV-1-positive blood donors in Catalonia. Continuous local epidemiological surveillance is required to implement optimal prevention strategies for controlling transfusion-transmitted HIV and to improve health policies regarding HIV infection.

Differences in the integrase and reverse transcriptase transmitted resistance patterns in Northern Poland

INTRODUCTION

With the widespread introduction of the integrase (In) inhibitors into clinical practice, transmission of drug resistance to this class of antiretroviral medications may expand. The aim of this study was to analyze the recent patterns of In resistance in treatment naive individuals in Northern Poland and its association with transmitted protease (PR) and reverse transcriptase (RT) mutations.

METHODS

Study included 172 PR, RT and InI sequences from antiretroviral treatment naive HIV-1 infected patients linked to care in Northern Poland from 2010 to 2015. Drug resistance was interpreted based on the WHO surveillance and IAS-USA mutation lists. For phylogeny maximum likelihood and Bayesian Monte Carlo Markov Chain analyses were used.

RESULTS

Overall rate of transmitted drug resistance was 12.21%. Nucleoside reverse transcriptase inhibitor (NRTI) resistance associated substitutions were found in 11.05% of cases and non-nucleoside reverse transcriptase inhibitor resistance variants in 1.16%. In multivariate models transmitted resistance strongly associated with subtype D infections [66.67% compared to the 3.84% for subtype B (p=0.001)]. No transmission of major protease or integrase mutations were observed. Polymorphisms associated with resistance against integrase inhibitor, mostly E157Q, were found in 21.5% sequences and associated with female (31.91% vs. 15.2% for male, p=0.01), injection drug use (84.21% compared to 22.08% for heterosexual and 1.39% for men-who-have-sex-with-men transmissions, p<0.0001) as well as hepatitis C coinfection [63.64% for positive, versus 8.57% for HCV antibody negative, p<0.0001]. Clusters of nucleoside reverse transcriptase mutations in subtype D and integrase E157Q variants in subtype B were observed.

CONCLUSIONS

Transmitted drug resistance frequency was high in subtype D but limited to clustered NRTI mutations, being infrequent among subtype B infected cases. Despite lack of major integrase resistance in treatment naive patients, variants potentially affecting susceptibility to this class were common, which indicates the potential need for extended surveillance in the near future.

Phylogeny and Phylogeography of a Recent HIV-1 Subtype F Outbreak among Men Who Have Sex with Men in Spain Deriving from a Cluster with a Wide Geographic Circulation in Western Europe

We recently reported the rapid expansion of an HIV-1 subtype F cluster among men who have sex with men (MSM) in the region of Galicia, Northwest Spain. Here we update this outbreak, analyze near full-length genomes, determine phylogenetic relationships, and estimate its origin. For this study, we used sequences of HIV-1 protease-reverse transcriptase and env V3 region, and for 17 samples, near full-length genome sequences were obtained. Phylogenetic analyses were performed via maximum likelihood. Locations and times of most recent common ancestors were estimated using Bayesian inference. Among samples analyzed by us, 100 HIV-1 F1 subsubtype infections of monophyletic origin were diagnosed in Spain, including 88 in Galicia and 12 in four other regions. Most viruses (n = 90) grouped in a subcluster (Galician subcluster), while 7 from Valladolid (Central Spain) grouped in another subcluster. At least 94 individuals were sexually-infected males and at least 71 were MSM. Seventeen near full-length genomes were uniformly of F1 subsubtype. Through similarity searches and phylogenetic analyses, we identified 18 viruses from four other Western European countries [Switzerland (n = 8), Belgium (n = 5), France (n = 3), and United Kingdom (n = 2)] and one from Brazil, from samples collected in 2005–2011, which branched within the subtype F cluster, outside of both Spanish subclusters, most of them corresponding to recently infected individuals. The most probable geographic origin and age of the Galician subcluster was Ferrol, Northwest Galicia, around 2007, while the Western European cluster probably emerged in Switzerland around 2002. In conclusion, a recently expanded HIV-1 subtype F cluster, the largest non-subtype B cluster reported in Western Europe, continues to spread among MSM in Spain; this cluster is part of a larger cluster with a wide geographic circulation in diverse Western European countries.

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

INTRODUCTION

The 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).

METHODS

The 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).

RESULTS

Eighty 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/mm(3) (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.

CONCLUSION

HIV-1 non-B-infected patients in Spain had a particular epidemiological and clinical profile that should be considered during their clinical management.

Epidemiological Surveillance of HIV-1 Transmitted Drug Resistance in Spain in 2004-2012: Relevance of Transmission Clusters in the Propagation of Resistance Mutations

Our objectives were to carry out an epidemiological surveillance study on transmitted drug resistance (TDR) among individuals newly diagnosed of HIV-1 infection during a nine year period in Spain and to assess the role of transmission clusters (TC) in the propagation of resistant strains. An overall of 1614 newly diagnosed individuals were included in the study from January 2004 through December 2012. Individuals come from two different Spanish regions: Galicia and the Basque Country. Resistance mutations to reverse transcriptase inhibitors (RTI) and protease inhibitors (PI) were analyzed according to mutations included in the surveillance drug-resistance mutations list updated in 2009. TC were defined as those comprising viruses from five or more individuals whose sequences clustered in maximum likelihood phylogenetic trees with a bootstrap value ≥90%. The overall prevalence of TDR to any drug was 9.9%: 4.9% to nucleoside RTIs (NRTIs), 3.6% to non-nucleoside RTIs (NNRTIs), and 2.7% to PIs. A significant decrease of TDR to NRTIs over time was observed [from 10% in 2004 to 2% in 2012 (p=0.01)]. Sixty eight (42.2%) of 161 sequences with TDR were included in 25 TC composed of 5 or more individuals. Of them, 9 clusters harbored TDR associated with high level resistance to antiretroviral drugs. T215D revertant mutation was transmitted in a large cluster comprising 25 individuals. The impact of epidemiological networks on TDR frequency may explain its persistence in newly diagnosed individuals. The knowledge of the populations involved in TC would facilitate the design of prevention programs and public health interventions.

HIV-1 subtype B-infected MSM may have driven the spread of transmitted resistant strains in France in 2007-12: impact on susceptibility to first-line strategies

BACKGROUND

Our study describes the prevalence of transmitted drug resistance (TDR) among 1318 French patients diagnosed at the time of primary HIV-1 infection (PHI) in 2007-12.

METHODS

HIV-1 resistance-associated mutations (RAMs) were characterized using both the 2009 WHO list of mutations and the French ANRS algorithm. A genotypic susceptibility score was estimated for each first-line recommended ART combination.

RESULTS

Patients were mainly MSM (72.6%). Non-B variants were identified in 33.7% of patients. The proportion of TDR was estimated as 11.7% (95% CI 10.0-13.5). The prevalences of PI-, NRTI-, first-generation NNRTI and etravirine/rilpivirine-associated RAMs were 2.5%, 5.2%, 3.9% and 3.2%, respectively. Single, dual and triple class resistance was found in 9.6%, 1.0% and 1.1% of cases, respectively. Additionally, 5/331 strains isolated in 2010-12 had integrase inhibitor (II)-related RAMs (isolated E157Q mutation in all cases). TDR was more common among MSM than in other groups (12.9% versus 8.6%, P = 0.034), and in case of B versus non-B subtype infections (13.6% versus 7.9%, P = 0.002). The proportions of fully active combinations were ≥99.2%, ≥97.3% and ≥95.3% in cases of PI-, II- and NNRTI-based regimens, respectively. In 2010-12, the proportion of fully active efavirenz-based ART was lower in cases of subtype B versus non-B infection (P = 0.021).

CONCLUSIONS

Compared with our previous studies, the proportion of NRTI- and first-generation NNRTI-related TDR has continued to decline in French seroconverters. However, subtype B-infected MSM could drive the spread of resistant HIV strains. Finally, we suggest preferring PI- or II- to NNRTI-based combinations to treat PHI patients.

Patterns of transmitted HIV drug resistance in Europe vary by risk group

Background

In Europe, a continuous programme (SPREAD) has been in place for ten years to study transmission of drug resistant HIV. We analysed time trends of transmitted drug resistance mutations (TDRM) in relation to the risk behaviour reported.

Methods

HIV-1 patients newly diagnosed in 27 countries from 2002 through 2007 were included. Inclusion was representative for risk group and geographical distribution in the participating countries in Europe. Trends over time were calculated by logistic regression.

Results

From the 4317 patients included, the majority was men-having-sex-with-men -MSM (2084, 48%), followed by heterosexuals (1501, 35%) and injection drug users (IDU) (355, 8%). MSM were more often from Western Europe origin, infected with subtype B virus, and recently infected (<1 year) (p<0.001). The prevalence of TDRM was highest in MSM (prevalence of 11.1%), followed by heterosexuals (6.6%) and IDU (5.1%, p<0.001). TDRM was predominantly ascribed to nucleoside reverse transcriptase inhibitors (NRTI) with a prevalence of 6.6% in MSM, 3.3% in heterosexuals and 2.0% in IDU (p = 0.001). A significant increase in resistance to non- nucleoside reverse transcriptase inhibitors (NNRTIs) and a decrease in resistance to protease inhibitors was observed in MSM (p = 0.008 and p = 0.006, respectively), but not in heterosexual patients (p = 0.68 and p = 0.14, respectively).

Conclusions

MSM showed to have significantly higher TDRM prevalence compared to heterosexuals and IDU. The increasing NNRTI resistance in MSM is likely to negatively influence the therapy response of first-line therapy, as most include NNRTI drugs.