non-B Subtype Infections Research Articles

Impact of HIV-1 subtypes on gross deletion in the nef gene after Korean Red Ginseng treatment

BackgroundThe number of primary human immunodeficiency virus (HIV)-1 non-B subtype infections (non-B) and that of reports regarding the differences in the pathogenesis of subtype B and non-B infections are increasing. However, to the best of our knowledge, there have been no reports on gross deletion in the nef gene (gΔnef) in non-B infections. MethodsTo determine whether there is a difference in the change in CD4+ T cells after treatment with Korean Red Ginseng (KRG) between patients with subtype B and non-B infections, we retrospectively analyzed and compared the annual decrease in CD4+ T cells (AD) and the proportion of gΔnef in 77 patients who were followed for more than 10 years in the absence of combination antiretroviral therapy. ResultsOverall, AD was significantly faster in patients with non-B infections than in those with subtype B infections. Survival analysis showed that the survival probability was significantly higher in subtype B than in non B-infected patients. These differences mainly resulted from significant differences in the amount of KRG and age. In the patients treated with KRG, there was a significant correlation between the amount of KRG and the AD in both subtypes. Interestingly, there was a significant correlation between the amount of KRG and the proportion of gΔnef in patients infected with subtype B, but not in those infected with non-B. The same phenomenon was observed when the KRG dose was adjusted. ConclusionOur results suggest that non-B may be biologically more stable than subtype B.

The Role of Phylogenetics in Unravelling Patterns of HIV Transmission towards Epidemic Control: The Quebec Experience (2002-2020).

Phylogenetics has been advanced as a structural framework to infer evolving trends in the regional spread of HIV-1 and guide public health interventions. In Quebec, molecular network analyses tracked HIV transmission dynamics from 2002–2020 using MEGA10-Neighbour-joining, HIV-TRACE, and MicrobeTrace methodologies. Phylogenetics revealed three patterns of viral spread among Men having Sex with Men (MSM, n = 5024) and heterosexuals (HET, n = 1345) harbouring subtype B epidemics as well as B and non-B subtype epidemics (n = 1848) introduced through migration. Notably, half of new subtype B infections amongst MSM and HET segregating as solitary transmissions or small cluster networks (2–5 members) declined by 70% from 2006–2020, concomitant to advances in treatment-as-prevention. Nonetheless, subtype B epidemic control amongst MSM was thwarted by the ongoing genesis and expansion of super-spreader large cluster variants leading to micro-epidemics, averaging 49 members/cluster at the end of 2020. The growth of large clusters was related to forward transmission cascades of untreated early-stage infections, younger at-risk populations, more transmissible/replicative-competent strains, and changing demographics. Subtype B and non-B subtype infections introduced through recent migration now surpass the domestic epidemic amongst MSM. Phylodynamics can assist in predicting and responding to active, recurrent, and newly emergent large cluster networks, as well as the cryptic spread of HIV introduced through migration.

Limited Sustained Local Transmission of HIV-1 CRF01_AE in New South Wales, Australia.

Australia’s response to the human immunodeficiency virus type 1 (HIV-1) pandemic led to effective control of HIV transmission and one of the world’s lowest HIV incidence rates—0.14%. Although there has been a recent decline in new HIV diagnoses in New South Wales (NSW), the most populous state in Australia, there has been a concomitant increase with non-B subtype infections, particularly for the HIV-1 circulating recombinant form CRF01_AE. This aforementioned CRF01_AE sampled in NSW, were combined with those sampled globally to identify NSW-specific viral clades. The population growth of these clades was assessed in two-year period intervals from 2009 to 2017. Overall, 109 NSW-specific clades were identified, most comprising pairs of sequences; however, five large clades comprising ≥10 sequences were also found. Forty-four clades grew over time with one or two sequences added to each in different two-year periods. Importantly, while 10 of these clades have seemingly discontinued, the remaining 34 were still active in 2016/2017. Seven such clades each comprised ≥10 sequences, and are representative of individual sub-epidemics in NSW. Thus, although the majority of new CRF01_AE infections were associated with small clades that rarely establish ongoing chains of local transmission, individual sub-epidemics are present and should be closely monitored.

Earlier Initiation of Antiretroviral Treatment Coincides With an Initial Control of the HIV-1 Sub-Subtype F1 Outbreak Among Men-Having-Sex-With-Men in Flanders, Belgium.

Human immunodeficiency virus type 1 (HIV-1) non-B subtype infections occurred in Belgium since the 1980s, mainly amongst migrants and heterosexuals, whereas subtype B predominated in men-having-sex-with-men (MSM). In the last decade, the diagnosis of F1 sub-subtype in particular has increased substantially, which prompted us to perform a detailed reconstruction of its epidemiological history. To this purpose, the Belgian AIDS Reference Laboratories collected HIV-1 pol sequences from all sub-subtype F1-infected patients for whom genotypic drug resistance testing was requested as part of routine clinical follow-up. This data was complemented with HIV-1 pol sequences from countries with a high burden of F1 infections or a potential role in the global origin of sub-subtype F1. The molecular epidemiology of the Belgian subtype F1 epidemic was investigated using Bayesian phylogenetic inference and transmission dynamics were characterized based on birth-death models. F1 sequences were retained from 297 patients diagnosed and linked to care in Belgium between 1988 and 2015. Phylogenetic inference indicated that among the 297 Belgian F1 sequences, 191 belonged to a monophyletic group that mainly contained sequences from people likely infected in Belgium (OR 26.67, 95% CI 9.59–74.15), diagnosed in Flanders (OR 7.28, 95% CI 4.23–12.53), diagnosed at a recent stage of infection (OR 7.19, 95% CI 2.88-17.95) or declared to be MSM (OR 34.8, 95% CI 16.0–75.6). Together with a Spanish clade, this Belgian clade was embedded in the genetic diversity of Brazilian subtype F1 strains and most probably emerged after one or only a few migration events from Brazil to the European continent before 2002. The origin of the Belgian outbreak was dated back to 2002 (95% higher posterior density 2000–2004) and birth-death models suggested that its extensive growth had been controlled (Re < 1) by 2012, coinciding with a time period where delay in antiretroviral treatment initiation substantially declined. In conclusion, phylogenetic reconstruction of the Belgian HIV-1 sub-subtype F1 epidemic illustrates the introduction and substantial dissemination of viral strains in a geographically restricted risk group that was most likely controlled by effective treatment as prevention.

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

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. 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. 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]. 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.

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.

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. 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. 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). 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.

Drug resistance in non-B subtype HIV-1: impact of HIV-1 reverse transcriptase inhibitors.

Human immunodeficiency virus (HIV) causes approximately 2.5 million new infections every year, and nearly 1.6 million patients succumb to HIV each year. Several factors, including cross-species transmission and error-prone replication have resulted in extraordinary genetic diversity of HIV groups. One of these groups, known as group M (main) contains nine subtypes (A-D, F-H and J-K) and causes ~95% of all HIV infections. Most reported data on susceptibility and resistance to anti-HIV therapies are from subtype B HIV infections, which are prevalent in developed countries but account for only ~12% of all global HIV infections, whereas non-B subtype HIV infections that account for ~88% of all HIV infections are prevalent primarily in low and middle-income countries. Although the treatments for subtype B infections are generally effective against non-B subtype infections, there are differences in response to therapies. Here, we review how polymorphisms, transmission efficiency of drug-resistant strains, and differences in genetic barrier for drug resistance can differentially alter the response to reverse transcriptase-targeting therapies in various subtypes.

Editorial Commentary: Extending HIV Drug Resistance Testing to Low Levels of Plasma Viremia

the variants in the circulation. Moreover, Food and Drug Administration (FDA)– approved HIV drug resistance genotyping platforms have specified application to specimens with >1000 copies HIV RNA/mL. Two companion papers in this issue of Clinical Infectious Diseases provide data from large clinical programs in British Columbia and central Italy to demonstrate that in fact the success rates for polymerase chain reaction (PCR) amplification to perform drug resistance testing in specimens from patients with 50–1000 copies HIV RNA/ mL plasma are both reasonably efficient and clinically predictive [6, 7]. Success rates were >90% for specimens >250 copies HIV RNA/mL in one study and for specimens >200 copies in the other. For specimens with detectable viral loads below these levels, successful sequencing results were still near 75%. In addition, the paper by Santoro et al showed that similarly successful rates were obtained with non-B subtype infections. Each of these studies provides a robust

HIV-1 Genetic Variability and Clinical Implications.

Despite advances in antiretroviral therapy that have revolutionized HIV disease management, effective control of the HIV infection pandemic remains elusive. Beyond the classic non-B endemic areas, HIV-1 non-B subtype infections are sharply increasing in previous subtype B homogeneous areas such as Europe and North America. As already known, several studies have shown that, among non-B subtypes, subtypes C and D were found to be more aggressive in terms of disease progression. Luckily, the response to antiretrovirals against HIV-1 seems to be similar among different subtypes, but these results are mainly based on small or poorly designed studies. On the other hand, differences in rates of acquisition of resistance among non-B subtypes are already being observed. This different propensity, beyond the type of treatment regimens used, as well as access to viral load testing in non-B endemic areas seems to be due to HIV-1 clade specific peculiarities. Indeed, some non-B subtypes are proved to be more prone to develop resistance compared to B subtype. This phenomenon can be related to the presence of subtype-specific polymorphisms, different codon usage, and/or subtype-specific RNA templates. This review aims to provide a complete picture of HIV-1 genetic diversity and its implications for HIV-1 disease spread, effectiveness of therapies, and drug resistance development.

Phylogenetic inferences on HIV-1 transmission

Phylogenetic inferences on HIV-1 transmission

Similar Short-Term Efficacy of Antiretroviral Therapy in Patients Infected With HIV B and Non–B Subtype Strains in France

Similar Short-Term Efficacy of Antiretroviral Therapy in Patients Infected With HIV B and Non–B Subtype Strains in France

Comparison of the RealTime HIV-1, COBAS TaqMan 48 v1.0, Easy Q v1.2, and Versant v3.0 assays for Determination of HIV-1 Viral Loads in a Cohort of Canadian Patients with Diverse HIV Subtype Infections

HIV clinics in Canada provide care to an increasing number of patients born outside of Canada with HIV-1 non-B subtype infections. Because the Easy Q HIV-1 v1.2 assay (EQ; bioMérieux) failed to detect some non-B subtype infections, a multiassay HIV-1 viral load (VL) study was conducted with patients with diverse HIV subtype infections. Patients were enrolled from the Southern Alberta HIV Clinic (SAC), Calgary, Alberta, Canada (n = 349) and the McGill HIV Clinic (MHC), Montreal, Quebec, Canada (n = 20) and had four or five tubes of blood drawn for testing by EQ and three other commercial HIV VL assays: (i) the Versant 3.0 HIV-1 test, with the Versant 440 instrument (branched DNA [bDNA]; Siemens), (ii) the RealTime HIV-1 test, with the m2000rt instrument (m2000rt; Abbott Molecular Diagnostics), and (iii) the COBAS AmpliPrep TaqMan HIV-1 48 test (CAP-CTM; Roche Molecular Diagnostics). Blood was processed according to the individual manufacturer's requirements and stored frozen at -86°C. The HIV subtype was known for patients who had undergone HIV genotypic resistance testing (Virco, Belgium). Data analyses were done using standard statistical methods within Stata 9.0 (StataCorp, College Station, TX). A total of 371 samples were tested on 369 patients, of whom 291 (81%) had a Virco genotype result of B (195; 53%) or non-B (96; 26%) subtypes A to D and F to K, as well as circulating recombinant forms (CRFs) (i.e., CRF01_AE and CRF02_AG). Most (58/78; 74%) patients of unknown subtype were recent African emigrants who likely have non-subtype B infection. Overall bias was small in pairwise Bland-Altman plots, but the limits of agreement between assays were wide. Discordant viral load results occurred for 98 samples and were due to missing values, false negatives, and significant underquantification that varied by HIV subtype. Results were obtained for all 371 samples with m2000rt, but for only 357 (97%) with CAP-CTM, 338 (92%) with EQ, and 276 (75%) with bDNA due to errors/equipment failures. False-negative results (nondetection of viral RNA versus other assay results) occurred for all platforms, as follows: for m2000rt, 8 (2%) [B(4) and non-B(4) subtypes], CAP-CTM, 9 (2.5%) [B(6) and non-B(3) subtypes]; EQ, 20 (6%) [B(7) and non-B(13) subtypes]; bDNA, 5 (2%) [B(1) and C(4)]. EQ and bDNA had the highest rates of underquantification by ≥ 1.0 log(10) copies/ml, mainly for HIV non-B subtypes. Performance significantly varied between HIV VL platforms according to subtype. HIV viral diversity in the population being tested must be considered in selection of the viral load platform.

Characteristics of HIV‐1 non‐B subtype infections in Northwest Poland

The number of non-B subtype HIV-1 infections in Europe has been increasing even though major regional differences have been observed. This trend was investigated in northwestern Poland using sequence and epidemiological data from a cohort of 102 HIV-1-infected patients from Szczecin, Poland. HIV-1 subtypes were defined by phylogenetic analysis of viral reverse transcriptase- and protease-partial coding regions, and results were compared with online subtyping by Standford and REGA tools. Subtype analysis using on-line subtyping methods produced varying results if compared to phylogenesis, with concordant variant assignment obtained for 98% (100/102) of sequences by Stanford and 85% (87/102) by REGA. In the population studied, non-B subtype infections comprised 21% of the infections and consisted of subtype D (57%, n = 12), CRF01_AE (19%, n = 4), A and C clades (9.5%, n = 2), and the CRF13_cpx recombinant isolate (4.8%, n = 1). Patients carrying non-B subtypes were predominantly heterosexuals with high percentage (57%) of women observed in the group. All HIV-1 non-B women were Caucasian with majority (83%) of infections acquired in Poland; however, among 12 travelers included in the study a higher proportion of non-B infections was noted (50%, P = 0.01). Moreover, lower baseline lymphocyte CD4 counts (P = 0.01), higher baseline HIV-1 viremia (P = 0.08), and a more advanced stage of the disease (P = 0.03) were observed among individuals infected with non-B subtypes. The data indicated that the proportion of HIV-1 non-B subtype infections was higher than previously reported in Poland consisting of a high subtype D prevalence. Furthermore, subtype D transmission occurred primarily between heterosexual Caucasian individuals from this region.

High prevalence of non‐B HIV‐1 subtypes in seamen and their sexual partners in Croatia

Travel influences the spread of non-B subtypes of HIV in Europe. The aim of this study was to assess whether the spread of non-B subtypes occurred in Croatia, a country with a low level HIV infection. Phylogenetic analysis of the reverse transcriptase and protease genes was undertaken in 145 Croatian patients with the following risks for HIV-infection: men who have sex with men (n = 64), heterosexual contact (n = 54), intravenous drug use (n = 21), bisexual contact (n = 4) and intravenous drug use plus heterosexual exposure (n = 2). The sample included 25 seamen and 13 steady female sexual partners of seamen. Overall, 38 (26%) of HIV-patients were infected with non-B subtypes. Non-B subtype infections were found only in patients with a possible heterosexual exposure. Non-B infections were most frequent in seamen and their regular female partners (in 27 of 38 seamen and their partners, 71%). The relative distribution of non-B subtypes was as follows: A, 8%; C, 26%; F, 3%; CRF01_AE, 8%; CRF02_AG, 34%; CRF05_DF, 5%; CRF06_cpx, 3%; CRF10_CD 8%; and subtype U, 5%. There were altogether 19 heterosexual couples, phylogenetic analysis confirmed that the paired samples were related in all cases. Non-B subtypes were found only in individuals with a heterosexual risk, mainly in seamen and their partners.

Clinical Differences and Viral Diversity between Newly HIV Type 1-Diagnosed African and Non-African Patients in Spain (2005–2007)

Abstract The diagnosis of HIV-1 is increasing in African-born persons residing in Europe. They present a high prevalence of HIV-1 non-B variant infections and of parasitic infections, both of which are infrequent in Western countries. Immigration favors their presence in nonendemic countries. In this study, all newly HIV-diagnosed individuals at an HIV/AIDS and Tropical Medicine reference center in Madrid from 2005 through 2007 were retrospectively studied. HIV-1 subtyping was performed in gag, pol, and gp41 coding regions by phylogenetic analyses. The presence of other pathogens was also evaluated. Furthermore, all HIV-1-infected Africans were screened for parasitic infections. Newly diagnosed HIV-1 subjects included 90 sub-Saharan Africans and 188 non-Africans (116 Spaniards, 13 other Europeans, and 59 Latin Americans). Significantly higher numbers of HIV-1-infected Africans than non-Africans were females, acquired HIV-1 by heterosexual contact, and presented a more advanced clinical CDC stage and criteria for starting antiretroviral therapy in the first clinical visit. They predominantly carried non-B subtype infections, mainly intersubtype recombinants. Half of HIV-1-infected Africans had parasitic infections. CD4(+) T cell counts were lower among Africans than Europeans at the time of HIV-1 diagnosis. At 12 months of follow-up after starting antiretroviral treatment, a significantly lower proportion of Africans than non-Africans achieved undetectable viremia due to their higher loss to follow-up. However, CD4(+) T cell recovery and virological failure rates were similar. Therefore, the profile of African HIV-1-infected immigrants varies widely with respect to Spanish HIV-infected individuals. More advanced immunodeficiency and the coexistence of parasitic diseases and infections with a large diversity of HIV-1 non-B and recombinant variants are expected.

Evidence for Onward Transmission of HIV-1 Non-B Subtype Strains in the United Kingdom

An increasing proportion of new HIV diagnoses in the United Kingdom and other European countries are attributable to non-B subtype infections, mainly among black Africans with infections heterosexually acquired in sub-Saharan Africa. We examined whether there was evidence for onward transmission of non-B subtypes within an ethnically diverse HIV-1-infected cohort in South London. Three hundred eighty-four HIV-1-infected patients attending Kings College Hospital were subtyped using an in-house enzyme-linked immunoassay and env sequencing. Epidemiologic data were obtained from medical chart review and the patients' physician and were used to establish the most likely source and country of infection. Overall, 344 patients (154 black African, 148 white UK-born, and 42 black Caribbean) had an identifiable subtype. The prevalence of non-B subtypes among the black African, white, and black Caribbean patients was 96.8%, 14.2%, and 31%, respectively. Most non-B subtype infections were identified in black Africans (149 of 183 cases) and were mainly acquired in sub-Saharan Africa, but 22.9% (42 of 183 cases) of all non-B infections were probably acquired in the United Kingdom. Among the 21 white UK-born patients infected with a non-B subtype, 15 probably acquired the infection in the United Kingdom and only 6 of these patients reported a source sexual partner from an HIV endemic area. All 13 black Caribbean patients with a non-B infection most likely acquired their infection in the United Kingdom, most of whom (8 of 13 patients) were probably infected by a partner from an HIV endemic area. Potential acquisition of HIV infection in the United Kingdom was lowest among black African patients with a non-B infection, and most of these infections were probably acquired from a partner originating from an HIV endemic area. This study provides the first evidence for onward transmission of non-B subtypes in the United Kingdom, particularly among the black Caribbean population.

Characterization of Complete HIV Type 1 Genomes from Non-B Subtype Infections in U.S. Military Personnel

Infections with non-B HIV-1 subtypes are rare in the United States, but comprise a significant percentage of infections among U.S. military personnel. Risk behavior while on overseas deployment correlates with non-B infection in this population. Extensive genetic characterization will be required to define HIV-1 diversity, and to effectively evaluate requirements for HIV-1 vaccines and other prevention strategies in this group. From 1997 to 2000, 520 recent seroconverters, identified through routine HIV-1 testing in the U.S. active military force, volunteered for a prospective study. V3 loop serology or partial genome sequencing identified 28 non- B subtype infections; 14 were studied by full genome sequencing and phylogenetic analysis. Five strains were CRF01_AE. Four of these clustered with CM240 from Thailand, and one clustered with African CRF01_AE. Four strains were CRF02_AG, prevalent in West and West Central Africa. Two strains were subtype C. One strain was a unique recombinant between CRF01_AE and subtype B, and another was a complex unique recombinant between subtype A and D. The final strain was a member of a complex circulating recombinant first identified in Senegal, CRF09_cpx, incorporating subtypes A, F, G, and an unclassified genome. This diversity of non-B subtype HIV-1 strains, encompassing three globally prevalent non-B strains and including rare or even possibly unique strains, illustrates the breadth of U.S. military exposure while deployed and sets the bar higher for breadth of cross-subtype protection to be afforded by an HIV-1 vaccine.

Diverse HIV-1 subtypes and clinical, laboratory and behavioral factors in a recently infected US military cohort.

To describe the demographics, risk behaviors, and HIV-1 subtypes in a large cohort of recently HIV-infected military personnel. Descriptive, cross-sectional study. US military personnel with recent HIV seroconversion from six medical referral centers were enrolled with a self-administered questionnaire, CD4 cell counts, syphilis and hepatitis B serologies, plasma viral RNA levels, and HIV-1 subtype nucleic acid sequencing. Between February 1997 and May 2000, 520 patients were enrolled. Most [488 (94.3%)] were infected with HIV-1 subtype B. The most prevalent non-B subtype was a circulating recombinant form (CRF01_AE) [17 (61%)]; however, two pure subtypes (C and D), as well as CRF02_AG, CRF09_cpx and a BE recombinant were identified. The likely area of HIV-1 acquisition was the United States for 70% of the volunteers. At least three non-B subtype infections (two subtype C, one subtype CRF01_AE) were apparently acquired domestically. Risk behaviors and comorbid sexually transmitted diseases were reported during the seroconversion period. Volunteers with non-B subtype HIV infection were more likely to report heterosexual contacts [92% vs. 39%; odds ratio (OR), 10.0], including contacts with commercial sex workers (41% vs. 13%; OR, 4.9). The Roche Amplicor version 1.0 assay was less sensitive for non-B subtype infections than the Roche Amplicor version 1.5 assay. There is a high prevalence and diversity of non-B HIV subtypes in this large cohort. Efficient diagnosis of acute primary HIV-1 infection was identified as a goal for prevention programs. Modifiable risk behaviors and target populations for intervention were identified.

National surveillance of HIV-1 subtypes for England and Wales: design, methods, and initial findings.

The HIV-1 infections detected in an ongoing national unlinked anonymous HIV surveillance program were subtyped and analyzed according to demographic and risk characteristics. Of the 893 anti--HIV-1--positive specimens allocated to an exposure group, 70% could be subtyped. Almost 25% of infections subtyped were non-B, mostly subtypes A, C, and D. Non-B infections were rare in homosexual and bisexual men and in drug injectors. Forty percent of infections in heterosexual men attending genitourinary medicine clinics were non-B subtypes; of these, 25% were subtype A infections and 59% were subtype C infections. For female clinic attendees, 61% were non-B subtype infections, of which 48% were subtype A infections and 42% were subtype C infections. Of the clinic attendees born in the United Kingdom and Europe, 14% of the men and 35% of the women were infected with non-B subtypes. In contrast, 78% of infections in antenatal patients were non-B subtypes, of which 61% were subtype A and 29% were subtype C. Extrapolation to the estimated 29,700 prevalent adult infections in the United Kingdom indicates that approximately 8,100 (27%) such infections are non-B subtypes and that these are found almost entirely in heterosexuals. The findings suggest spread of infection of non-B subtypes to heterosexuals born in the United Kingdom from individuals infected in regions of high prevalence.

HIV-1 genetic diversity in Galicia Spain: BG intersubtype recombinant viruses circulating among injecting drug users.

The HIV-1 epidemics in Western Europe are dominated by B subtype viruses. Non-B subtype is largely restricted to individuals infected outside of Europe and to their direct contacts and is generally acquired by the heterosexual route. Protease and a segment of reverse transcriptase were amplified and sequenced from plasma RNA in 451 individuals from seven cities of Galicia, north-western Spain. Subtype sequence homologies were determined using the BLAST algorithm. Non-B sequences were examined by phylogenetic analysis and intersubtype recombination by bootscanning. The env V3 region was analysed in all non-B and in 38 B subtype viruses. Ten different non-B genetic forms were identified in 20 (4.4%) individuals. Subtypes were concordant between pol and V3 in five viruses; 14 (70%) infections were with intersubtype recombinant viruses, and one individual had a dual B+G infection. Seven recombinant viruses were phylogenetically related to five reported recombinant forms. Three non-recombinant G and six recombinant BG viruses formed a monophyletic cluster for pol. All but three individuals with non-B infections were native Spanish. Only 6 of 16 individuals referred to sexual contacts with sub-Saharan Africans. Twelve (60%) non-B subtype infections, including all with G and BG viruses, were in injecting drug users (IDU). Non-B subtype viruses were identified in 4.4%, with a high diversity of genetic forms, including 70% infections with intersubtype recombinant viruses. The majority of individuals with non-B infections were IDU, most of them without known contacts with non-European sources, and among whom BG recombinant viruses are circulating.