Transmitted HIV drug resistance in treatment-naive Romanian patients

Characterization of Human Immunodeficiency Virus-1 Transmission Clusters and Transmitted Drug-Resistant Mutations in Croatia from 2019 to 2022

Molecular epidemiology of HIV-1 infection is challenging due to the highly diverse HIV-genome. We investigated the genetic diversity and prevalence of transmitted drug resistance (TDR) followed by phylogenetic analysis in 270 HIV-1 infected, treatment-naïve individuals from Croatia in the period 2019-2022. The results of this research confirmed a high overall prevalence of TDR of 16.7%. Resistance to nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside RTIs (NNRTIs), and protease inhibitors (PIs) was found in 9.6%, 7.4%, and 1.5% of persons, respectively. No resistance to integrase strand-transfer inhibitors (INSTIs) was found. Phylogenetic analysis revealed that 173/229 sequences (75.5%) were part of transmission clusters, and the largest identified was T215S, consisting of 45 sequences. Forward transmission was confirmed in several clusters. We compared deep sequencing (DS) with Sanger sequencing (SS) on 60 randomly selected samples and identified additional surveillance drug resistance mutations (SDRMs) in 49 of them. Our data highlight the need for baseline resistance testing in treatment-naïve persons. Although no major INSTIs were found, monitoring of SDRMs to INSTIs should be continued due to the extensive use of first- and second-generation INSTIs.

Ageing People Living with HIV/AIDS, PLWHA; More Dental Challenges; the Romanian Dental Professional's Point of View

BACKGROUND

In Romania, HIV (human immunodeficiency virus) and AIDS (acquired immunodeficiency syndrome) were first acknowledged in 1989. Getting older with HIV/AIDS is now possible due to antiretroviral treatment, but it can bring dental problems due to HIV itself or to the reluctance of dental professionals to treat dental problems. Our study aims to assess the attitudes, knowledge, and practices of Romanian dental professionals regarding aging PLWHA.

METHODS

An analytical cross-sectional observational survey based on a self-administered questionnaire was conducted for Romanian dental professionals from October 2022 to January 2023.

RESULTS

The responders' group profile was as follows: a mean age of 39.09 ± 0.36 years (limit: 19-75), a majority of 991 (90.01%) from urban dental offices, and 364 (33.06%) with more than twenty years' experience. A total of 517 (46.95%) responders had an unprofessional attitude and declared that, if possible, they would avoid taking part in performing dental treatments for people living with HIV/AIDS (PLWHA). There were 89 (8.08%) dental professionals that refused to work with PLWHA. Only 363 (32.97%) had worked with one previously. The dental professionals in rural areas refused PLWHA more frequently: 20% (N = 22) of rural dental professionals vs. 6.76% (N = 67) of urban dental professionals refused to work with PLWHA (OR = 0.30; 95% CI: 0.16-.56). The logistic regression applied for the 1101 responders revealed after stepwise selection that the most influential factor for their refusal to work with PLWHA in our study group was being previously exposed to HIV during dental practice (OR = 14.45; 95% CI: 8.55- 24.42; p = 0.000).

CONCLUSIONS

Dental educators and health care planners should promote the knowledge of prophylaxis and positive attitudes towards the treatment of PLWHA. Successful resolution of these concerns is time consuming and expensive but necessary if dentists are to satisfy their professional obligations to HIV/AIDS patients.

Transmitted HIV Drug Resistance in Bulgaria Occurs in Clusters of Individuals from Different Transmission Groups and Various Subtypes (2012-2020)

Transmitted HIV drug resistance in Bulgaria was first reported in 2015 using data from 1988-2011. We determined the prevalence of surveillance drug resistance mutations (SDRMs) and HIV-1 genetic diversity in Bulgaria during 2012-2020 using polymerase sequences from 1053 of 2010 (52.4%) antiretroviral therapy (ART)-naive individuals. Sequences were analyzed for DRM using the WHO HIV SDRM list implemented in the calculated population resistance tool at Stanford University. Genetic diversity was inferred using automated subtyping tools and phylogenetics. Cluster detection and characterization was performed using MicrobeTrace. The overall rate of SDRMs was 5.7% (60/1053), with 2.2% having resistance to nucleoside reverse transcriptase inhibitors (NRTIs), 1.8% to non-nucleoside reverse transcriptase inhibitors (NNRTIs), 2.1% to protease inhibitors (PIs), and 0.4% with dual-class SDRMs. We found high HIV-1 diversity, with the majority being subtype B (60.4%), followed by F1 (6.9%), CRF02_AG (5.2%), A1 (3.7%), CRF12_BF (0.8%), and other subtypes and recombinant forms (23%). Most (34/60, 56.7%) of the SDRMs were present in transmission clusters of different subtypes composed mostly of male-to-male sexual contact (MMSC), including a 14-member cluster of subtype B sequences from 12 MMSC and two males reporting heterosexual contact; 13 had the L90M PI mutation and one had the T215S NRTI SDRM. We found a low SDRM prevalence amid high HIV-1 diversity among ART-naive patients in Bulgaria during 2012-2020. The majority of SDRMs were found in transmission clusters containing MMSC, indicative of onward spread of SDRM in drug-naive individuals. Our study provides valuable information on the transmission dynamics of HIV drug resistance in the context of high genetic diversity in Bulgaria, for the development of enhanced prevention strategies to end the epidemic.

Disparity of HIV-1 Pretreatment Drug Resistance in Men Who Have Sex With Men and the Heterosexual Population in Guangxi, China

Background

The prevalence of human immunodeficiency type 1 (HIV-1) pretreatment drug resistance (PDR) in men who have sex with men (MSM) in Guangxi remains unclear, and its effect on antiretroviral therapy (ART) needs to be further studied.

Methods

Individuals newly diagnosed with HIV in Guangxi from 2016 to 2020, which mainly included MSM and the heterosexual (HES) population, were recruited in this study. Pol sequences were sequenced to analyze PDR and construct a genetic network. The risk factors for PDR and the effect on ART were respectively analyzed.

Results

The PDR of MSM in Guangxi was 4.7% (34/716), consisting of nonnucleoside reverse transcriptase inhibitors (3.5%), protease inhibitors (0.8%), integrase strand transfer inhibitors (0.7%), and nucleoside reverse transcriptase inhibitors (0.4%), and lower than that of HES (9.3% [77/827]). The subtype was associated with PDR, and MSM was lower than HES (CRF01_AE: 3.0% vs 8.0%; CRF07_BC: 4.1% vs 7.2%). CRF55_01B (adjusted odds ratio [aOR], 3.35) was a risk factor for PDR in MSM, while CRF08_BC (aOR, 2.34) and older (aOR, 2.75) were risk factors for PDR in HES. Six of 18 (33.3%) PDR of MSM in the network connected to each other, lower than that of HES (61.1% [22/36]). CRF55_01B (aOR, 5.69) was a risk factor for PDR transmission in MSM, while CRF08_BC (aOR, 4.08) was a risk factor in HES. Pretreatment CD4⁺ T-cell count, age, infection route, and subtype were associated with recovery of CD4⁺ count and suppression of viral load.

Conclusions

The prevalence of PDR was different between MSM and HES, which may be associated with subtype. Thus, the monitoring of subtype and PDR should be strengthened.

Romania, a Harbour of HIV-1 Subtype F1: Where Are We after 33 Years of HIV-1 Infection?

Infection with the human immunodeficiency virus (HIV) has been a major public health concern worldwide for more than 30 years, including in Romania. The F1 HIV-1 subtype was exported from Angola to Romania most probably because of the two countries' close political connections. Patients infected with HIV-1 via re-used and improperly sterilized injection equipment and through transfusions of unscreened blood, also known as the "Romanian cohort", were the most common type of HIV-1 infection in Romania in the early 1990s, when the virus's presence was recognized. Recently, subtype B started to increase in our country, mostly diagnosed in people using intravenous drugs or in men having sex with men. The evolution of the HIV-1 infection in Romania has been unique, with a dominance of the subtype F1, making it different from other countries in Europe.

Prevalence of resistance mutations associated with integrase inhibitors in therapy-naive HIV-positive patients in Hungary

Widespread introduction of HIV integrase inhibitors into clinical care may result in appearance of drug resistance mutations affecting treatment outcome. The aim of our study was to monitor the resistance patterns of integrase inhibitors beside protease and reverse transcriptase inhibitors in newly diagnosed therapy-naive HIV-positive patients in Hungary between 2017 and 2019.Genotype-based resistance testing of HIV integrase, protease and reverse transcriptase was performed by amplification and Sanger population sequencing from plasma samples. Drug resistance mutations were identified by the algorithm of Stanford HIV Drug Resistance Database.Potentially transmitted, non-polymorphic integrase major mutation was detected in 1 out of 249 samples, while accessory mutations were observed in further 31 patients (12.4%). The overall prevalence of transmitted drug resistance (TDR) mutations related to protease and reverse transcriptase inhibitors was 5.8% (10/173) between the end of 2017 and 2019. Nucleoside reverse transcriptase inhibitor associated resistance mutations were the most frequent indicators of TDR (6/173; 3.5%), followed by resistance mutations associated with protease (3/173; 1.7%) and non-nucleoside reverse transcriptase inhibitors (2/173, 1.2%).The first detection of integrase major mutation and the changing patterns of other resistance mutations in Hungarian untreated HIV-positive population indicate the necessity of continuous molecular surveillance of Hungarian HIV epidemic.

HIV drug resistance and HIV transmission risk factors among newly diagnosed individuals in Southwest China

Background

The widespread use of antiretroviral therapy (ART) has resulted in the development of transmitted drug resistance (TDR), which reduces ART efficacy. We explored TDR prevalence and its associated risk factors in newly diagnosed individuals in Guangxi.

Methods

We enrolled 1324 participants who were newly diagnosed with HIV-1 and had not received ART at voluntary counselling and testing centres (VCT) in Guangxi, China, who had not received ART. Phylogenetic relationship, transmission cluster, and genotypic drug resistance analyses were performed using HIV-1 pol sequences. We analysed the association of demographic and virological factors with TDR.

Results

In total, 1151 sequences were sequenced successfully, of which 83 (7.21%) showed evidence of TDR. Multivariate logistic regression analysis revealed that there was significant difference between the prevalence of TDR and unmarried status (adjusted odds ratio (aOR) = 2.41, 95% CI: 1.23–4.71), and CRF08_BC subtype (aOR = 2.03, 95% CI: 1.13–3.64). Most cases of TDR were related to resistance to non-nucleoside reverse transcriptase inhibitors (4.87%) and V179E was the most common mutation detected. We identified a total of 119 HIV transmission clusters (n = 585, 50.8%), of which 18 (15.1%) clusters showed evidence of TDR (36, 41.86%). Three clusters were identified that included drug-resistant individuals having a transmission relationship with each other. The following parameters were associated with TDR transmission risk: Unmarried status, educational level of junior high school or below, and CRF08_BC subtype may be a risk of the transmission of TDR.

Conclusions

Our findings indicated that moderate TDR prevalence and highlighted the importance of continuous TDR monitoring and designing of strategies for TDR mitigation.

Analysis of HIV-1 diversity, primary drug resistance and transmission networks in Croatia

Molecular epidemiology of HIV-1 infection in treatment-naive HIV-1 infected persons from Croatia was investigated. We included 403 persons, representing 92.4% of all HIV-positive individuals entering clinical care in Croatia in 2014–2017. Overall prevalence of transmitted drug resistance (TDR) was estimated at 16.4%. Resistance to nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside RTI (NNRTIs) and protease inhibitors (PIs) was found in 11.4%, 6.7% and 2.5% of persons, respectively. Triple-class resistance was determined in 2.2% of individuals. In addition, a single case (1.0%) of resistance to integrase strand-transfer inhibitors (InSTIs) was found. Deep sequencing was performed on 48 randomly selected samples and detected additional TDR mutations in 6 cases. Phylogenetic inference showed that 347/403 sequences (86.1%) were part of transmission clusters and identified forward transmission of resistance in Croatia, even that of triple-class resistance. The largest TDR cluster of 53 persons with T215S was estimated to originate in the year 1992. Our data show a continuing need for pre-treatment HIV resistance testing in Croatia. Even though a low prevalence of resistance to InSTI was observed, surveillance of TDR to InSTI should be continued.

Transmitted drug resistance in newly diagnosed and treatment-naïve HIV type 1-infected patients in Hungary

OBJECTIVES

Transmitted human immunodeficiency virus type 1 (HIV-1) drug resistance (TDR) may affect the success of first-line antiretroviral treatment. This study aimed to monitor the presence of HIV-1 strains carrying transmitted drug resistance-associated mutations (TDRMs) in newly diagnosed and treatment-naïve patients in Hungary.

METHODS

This study included 168 HIV-infected individuals diagnosed between 2013-2017; most of them (93.5%) belonged to the homo/bisexual population. HIV-1 subtypes and TDRMs were determined by analysing the protease and reverse transcriptase coding regions of the pol gene by the Stanford HIV Drug Resistance Database. Transmission clusters among patients were identified using phylogenetic analysis.

RESULTS

Although subtype B HIV-1 strains were predominant (87.5%), non-B subtypes including F, A, CRF01_AE, CRF02_AG, D and G were also recorded, especially in young adults. The overall prevalence of TDR was 10.7% (18 of 168; 95% CI: 6.9-16.3%). Subtype B HIV-1 strains carried most of the TDRMs (94.4%). Nucleoside reverse transcriptase inhibitor (NRTI)-associated mutations were the most prevalent indicators of TDR (16 of 168; 9.5%; 95% CI: 5.9-14.9%), followed by mutations conferring resistance to non-nucleoside reverse transcriptase inhibitors (NNRTIs) (2 of 168; 1.2%; 95% CI: 0.3-4.2%) and protease inhibitors (PIs) (1 of 168, 0.6%; 95% CI: 0.1-3.3%). Phylogenetic analysis revealed that most NRTI-associated resistance mutations were associated with a single monophyletic clade, suggesting early single-source introduction and ongoing spread of this drug-resistant HIV-1 strain.

CONCLUSIONS

Onward transmission of drug-resistant subtype B HIV-1 strains accounted for the majority of TDRs observed among treatment-naïve HIV-infected individuals in Hungary.

Diverse Large HIV-1 Non-subtype B Clusters Are Spreading Among Men Who Have Sex With Men in Spain

In Western Europe, the HIV-1 epidemic among men who have sex with men (MSM) is dominated by subtype B. However, recently, other genetic forms have been reported to circulate in this population, as evidenced by their grouping in clusters predominantly comprising European individuals. Here we describe four large HIV-1 non-subtype B clusters spreading among MSM in Spain. Samples were collected in 9 regions. A pol fragment was amplified from plasma RNA or blood-extracted DNA. Phylogenetic analyses were performed via maximum likelihood, including database sequences of the same genetic forms as the identified clusters. Times and locations of the most recent common ancestors (MRCA) of clusters were estimated with a Bayesian method. Five large non-subtype B clusters associated with MSM were identified. The largest one, of F1 subtype, was reported previously. The other four were of CRF02_AG (CRF02_1; n = 115) and subtypes A1 (A1_1; n = 66), F1 (F1_3; n = 36), and C (C_7; n = 17). Most individuals belonging to them had been diagnosed of HIV-1 infection in the last 10 years. Each cluster comprised viruses from 3 to 8 Spanish regions and also comprised or was related to viruses from other countries: CRF02_1 comprised a Japanese subcluster and viruses from 8 other countries from Western Europe, Asia, and South America; A1_1 comprised viruses from Portugal, United Kingom, and United States, and was related to the A1 strain circulating in Greece, Albania and Cyprus; F1_3 was related to viruses from Romania; and C_7 comprised viruses from Portugal and was related to a virus from Mozambique. A subcluster within CRF02_1 was associated with heterosexual transmission. Near full-length genomes of each cluster were of uniform genetic form. Times of MRCAs of CRF02_1, A1_1, F1_3, and C_7 were estimated around 1986, 1989, 2013, and 1983, respectively. MRCA locations for CRF02_1 and A1_1 were uncertain (however initial expansions in Spain in Madrid and Vigo, respectively, were estimated) and were most probable in Bilbao, Spain, for F1_3 and Portugal for C_7. These results show that the HIV-1 epidemic among MSM in Spain is becoming increasingly diverse through the expansion of diverse non-subtype B clusters, comprising or related to viruses circulating in other countries.

C. Pardini MI, Feiteiro MVC, Tolentino FM, Diaz RS, Lopes GISL, Francisco RBL, Véras NMC, Pires AF, Franchini M, Mesquita F, Tanuri A. Brazilian network for HIV Drug Resistance Surveillance (HIV-BresNet): a survey of treatment-naive individuals

INTRODUCTION

In Brazil, more than 487,450 individuals are currently undergoing antiretroviral treatment. In order to monitor the transmission of drug-resistant strains and HIV subtype distribution in the country, this work aimed to estimate its prevalence and to characterize the nationwide pretreatment drug resistance in individuals recently diagnosed with HIV between 2013 and 2015.

METHODS

The HIV threshold survey methodology (HIV-THS, WHO) targeting antiretroviral-naive individuals with recent HIV diagnosis was utilized, and subjects were selected from 51 highly populated cities in all five Brazilian macroregions. The HIV pol genotypic test was performed by genomic sequencing.

RESULTS

We analysed samples from 1568 antiretroviral-naive individuals recently diagnosed with HIV, and the overall transmitted drug resistance (TDR) prevalence was 9.5% (150 sequences). The regional prevalence of resistance according to Brazilian geographical regions was 9.4% in the northeast, 11.2% in the southeast, 6.8% in the central region, 10.2% in the north and 8.8% in the south. The inhibitor-specific TDR prevalence was 3.6% for nucleoside reverse transcriptase inhibitors (NRTIs), 5.8% for non-nucleoside reverse transcriptase inhibitors (NNRTIs) and 1.6% for protease inhibitors (PIs); 1.0% of individuals presented resistance to more than one class of inhibitors. Overall, subtype B was more prevalent in every region except for the southern, where subtype C prevails.

CONCLUSIONS

To the best of our knowledge, this is the first TDR study conducted in Brazil with nationwide representative sampling. The TDR prevalence revealed a moderate rate in the five Brazilian geographical regions, although some cities presented higher TDR prevalence rates, reaching 14% in São Paulo, for example. These results further illustrate the importance of surveillance studies for designing future strategies in primary antiretroviral therapy, aiming to mitigate TDR, as well as for predicting future trends in other regions of the globe where mass antiretroviral (ARV) treatment was implemented.

Defining HIV-1 transmission clusters based on sequence data

Understanding HIV-1 transmission dynamics is relevant to both screening and intervention strategies of HIV-1 infection. Commonly, HIV-1 transmission chains are determined based on sequence similarity assessed either directly from a sequence alignment or by inferring a phylogenetic tree. This review is aimed at both nonexperts interested in understanding and interpreting studies of HIV-1 transmission, and experts interested in finding the most appropriate cluster definition for a specific dataset and research question. We start by introducing the concepts and methodologies of how HIV-1 transmission clusters usually have been defined. We then present the results of a systematic review of 105 HIV-1 molecular epidemiology studies summarizing the most common methods and definitions in the literature. Finally, we offer our perspectives on how HIV-1 transmission clusters can be defined and provide some guidance based on examples from real life datasets.

HIV transmission clusters among injecting drug users in Romania

Injection drug use is increasingly an important route of HIV transmission in Romania (from 1.5% of the newly diagnosed cases prior to 2010 to 31% in 2013). In this study we investigated the viral characteristics and relationships in newly HIV infected persons who inject drugs in Bucharest, Romania.

RESULTS

HIV-1 pol sequencing, followed by phylogenetic and clustering analysis was performed on blood from 37 injecting drug users (IDUs) newly diagnosed with HIV infection. While HIV subtype F1, the dominant strain in Romania since 1990, remains prevalent, new subtypes were found including G, B, B/G and B/F recombinants. Overall, 27 of the available sequences (72.9%) clustered with at least one other. Network and phylogenetic analysis revealed tight monophyletic clusters for both subtypes F and G, with short genetic distances between sequences, suggesting recent numerous acute to acute transmissions or single burst-type episodes. No transmitted drug-resistance mutations were identified. Greater immunosuppression was present in subjects forming the subtype G cluster, possibly indicating a faster rate of progression associated with this subtype.

CONCLUSIONS

The recent increasing numbers of IDU related HIV transmissions in Bucharest, has resulted in closely-knit transmission networks that maychange the genetic profile of the local HIV epidemic.

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

OBJECTIVES

To determine transmitted drug resistance (TDR) and HIV-1 genetic diversity in Bulgaria.

METHODS

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.

RESULTS

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%).

CONCLUSIONS

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.

Molecular tools for studying HIV transmission in sexual networks

PURPOSE OF REVIEW

Phylogenetics is frequently used for studies of population-based HIV transmission. The purpose of this review is to highlight the current utilities and limitations of phylogenetics in HIV epidemiological research from sample collection through to data analysis.

RECENT FINDINGS

Studies of HIV phylogenies can provide critical information about HIV epidemics that are otherwise difficult to obtain through traditional study design such as transmission of drug-resistant virus, mixing between demographic groups, and rapidity of viral spread within populations. However, recent results from empirical and theoretical studies of HIV phylogenies challenge some of the key assumptions and interpretations from phylogenetic studies. Recent findings include lack of transmission bottlenecks in MSM and injection drug use epidemics, evidence for preferential transmission of HIV virus in heterosexual epidemics, and limited evidence that tree topologies correlate directly with underlying network structures. Other challenges include a lack of a standardized definition for a phylogenetic transmission cluster and biased or sparse sampling of HIV transmission networks.

SUMMARY

Phylogenetics is an important tool for HIV research, and offers opportunities to understand critical aspects of the HIV epidemic. Like all epidemiological research, the methods used and interpretation of results from phylogenetic studies should be made cautiously with careful consideration.

Similar replicative fitness is shared by the subtype B and unique BF recombinant HIV-1 isolates that dominate the epidemic in Argentina

The HIV-1 epidemic in South America is dominated by pure subtypes (mostly B and C) and more than 7 BF and BC recombinant forms. In Argentina, circulating recombinant forms (CRFs) comprised of subtypes B and F make up more than 50% of HIV infections. For this study, 28 HIV-1 primary isolates were obtained from patients in Buenos Aires, Argentina and initially classified into subtype B (n = 9, 32.1%), C (n = 1, 3.6%), and CRFs (n = 18, 64.3%) using partial pol and vpu-env sequences, which proved to be inconsistent and inaccurate for these phylogenetic analyses. Near full length genome sequences of these primary HIV-1 isolates revealed that nearly all intersubtype BF recombination sites were unique and countered previous "CRF" B/F classifications. The majority of these Argentinean HIV-1 isolates were CCR5-using but 4 had a dual/mixed tropism as predicted by both phenotypic and genotypic assays. Comparison of the replicative fitness of these BF primary HIV-1 isolates to circulating B, F, and C HIV-1 using pairwise competitions in peripheral blood mononuclear cells (PBMCs) indicated a similarity in fitness of these BF recombinants to subtypes B and F HIV-1 (of the same co-receptor usage) whereas subtype C HIV-1 was significantly less fit than all as previously reported. These results suggest that the multitude of BF HIV-1 strains present within the Argentinean population do not appear to have gained replicative fitness following recent B and F recombination events.

The emerging and re-emerging human immunodeficiency virus epidemics in Europe

We provide a summary of the current status of the human immunodeficiency virus (HIV) epidemic, including data on the transmission of drug-resistant virus in the European Region of the WHO. The review was conducted by searching the reports of the European Centre for Disease Prevention and Control and the United Nations General Assembly Special Session country reports to identify the number of HIV cases reported in 2002-2011, the number of HIV tests performed, and the results of the most recent HIV surveys in at-risk groups. In the West, a 5-year linear trend analysis suggests an increase in the number of reported HIV cases in Belgium, Greece, and Iceland, and a decline in The Netherlands, Ireland, Portugal, Switzerland, and the UK. In the Centre, the number of reported cases increased in Bulgaria and Turkey, and in the East, the number of reported cases increased in Armenia, Georgia, and Ukraine. Estonia and Latvia reported a significant downward trend. HIV transmission in men who have sex with men (MSM) and heterosexual transmission accounted for, respectively, 40% and 38% of newly reported HIV cases in the West in 2011, whereas the epidemic in the Centre is predominantly concentrated in MSM. Although injection drug use remains the key driving force of the epidemic in the East, there is increasing evidence of sexual transmission from the core groups of injection drug users, and increasing spread within MSM. The pattern of transmitted drug resistance (TDR) is heterogeneous accross Europe; a significant number of clusters of TDR have been recently observed in several European countries.