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1.  Distinct HIV Type 1 Strains in Different Risk Groups and the Absence of New Infections by Drug-Resistant Strains in Lithuania 
To analyze HIV-1 genotypes in Lithuania and the transmission of drug-resistant viruses, HIV-1 sequences were obtained from 138 individuals, who were diagnosed as HIV-1 infected in 1990–2008 and represented all major risk groups. Subtype A strains, dominating in the former Soviet Union (90% of cases), were found in 60% of individuals, followed by subtype B (22%) and CRF03_AB (12%) strains. The remaining 7% of the strains included variants belonging to subtype C, CRF01_AE, CRF02_AG, more complex recombinant forms, and strains that could not be reliably genotyped. Analysis of virus genotypes per risk group revealed the circulation of distinct HIV-1 strains in different risk groups: subtype A viruses were present in 82% of injecting drug users (IDUs), but less than a half of heterosexually infected individuals and cases with unknown transmission route, and none of men having sex with men (MSM). We observed no mutations causing drug resistance among 27 newly diagnosed HIV-1 cases.
PMCID: PMC3607974  PMID: 23186249
2.  AIDS: The Final Chapter? 
PMCID: PMC3887424  PMID: 24392796
3.  Prevalence of Drug Resistance in Human Immunodeficiency Virus Type 1-Infected Treatment-Naive Children in Pune, India 
We report the presence of drug resistance mutations in 7.4% (2/27) of the treatment-naive, HIV-1-infected children in Pune, India, who had HIV-1 RNA levels >1,000 copies/ml. Nonnucleoside reverse transcriptase inhibitor (NNRTI) mutations, namely A98G and K103N, were observed in two separate sequences. In addition, three study sequences displayed three separate HIV-1 protease minor resistance mutations—L10I, A71T, and T74S. These preliminary data from Pune, India, reporting the presence of HIVDR in treatment-naive, HIV-1-infected children, reinforces the need to conduct large-scale studies to assess the prevalence of primary HIVDR in the pediatric population, which in turn will aid in planning protocols and policies related to antiretroviral treatment for the pediatric population.
PMCID: PMC3938931  PMID: 24387706
4.  Identification of a Novel HIV-1 Second-Generation Recombinant Form (CRF01_AE/CRF07_BC) in Jilin, China 
We report here a novel HIV-1 second-generation recombinant form (CRF01_AE/CRF07_BC) isolated from an HIV-positive male subject infected through heterosexual contact in Jilin province in northeastern China. Phylogenic analysis shows that this novel second-generation recombinant (JL.RF09) was composed of two well-established circulating recombinant forms (CRF01_AE and CRF07_BC), with two recombinant breakpoints observed in the vpu/env and env gene regions, respectively. The CRF01_AE region of the recombinant was clustered together with a previously described subcluster 4a lineage of CRF01_AE, which is exclusively circulating among men who have sex with men (MSM) in northern China, indicating that the parental origin of the CRF01_AE region in JL.RF09 was from MSM in north China. The CRF07_BC regions of the recombinant are clustered within the CRF07_BC cluster but are distinct from other CRF07_BC references. The detailed origin of CRF07_BC in this recombinant is still not clear. The emergence of the novel HIV-1 recombinant indicates the ongoing generation of recombinants involving CRF01_AE and CRF07_BC, and may provide vital insights into our understanding of the dynamics and complexity of the HIV-1 epidemic in China.
PMCID: PMC4118697  PMID: 24892359
5.  Near Full-Length Genome Sequence of a Novel HIV-1 Recombinant Form (CRF01_AE/B) Detected Among Men Who Have Sex with Men in Jilin Province, China 
We report here a novel HIV-1 recombinant form (CRF01_AE/B) detected from a comprehensive HIV-1 molecular epidemiologic study among men who have sex with men (MSM) in Jilin province of northeastern China. The near full-length genome (NFLG) analyses showed that the novel HIV-1 recombinant isolate (JL.RF07) was composed of CRF01_AE cluster 5 (northeastern China origin) and subtype B (U.S. and European origin), with six recombinant breakpoints observed in the pol, vif, tat, rev, and env gene regions. To the best of our knowledge, this is the first detection of a novel HIV-1 recombinant form (CRF01_AE/B) in Jilin, which may indicate an active transmission network of HIV-1 infection among MSM in the region. Further studies of the molecular epidemiology of the HIV-1 epidemic among MSM in northeastern China are necessary to gain a fuller understanding of the transmission network and potential public health impact of HIV-1 among MSM in this region.
PMCID: PMC4076975  PMID: 24521207
6.  Molecular Characterization of Unique Intersubtype HIV Type 1 A1/C Recombinant Strain Circulating in Pune, India 
AIDS Research and Human Retroviruses  2013;29(9):1245-1253.
An increasing number of circulating recombinant forms (CRFs) and unique recombinant forms (URFs) all over the world has necessitated being vigilant about new recombinants. Since the first report of a recombinant virus with an A1/C mosaic in 1998 more and more B/C and A/C recombinant viruses are being reported from India. Here we report the identification and characterization of a unique HIV-1 A1/C recombinant circulating in Western India. Analysis of the full-length genome using RIP, SimPlot, and jpHMM@Gobics has confirmed its mosaic structure with insertion of subtype A1 in the backbone of subtype C at three positions: gag-pol (1973±15–2617±47), pol-vif (4879±37–5582±32), and gp41 (8437±106–8811±8); however, RIP and SimPlot showed one more small insertion in integrase (4343–4519). Phylogenetic analysis confirmed that the recombinant virus has an insertion of clade A1 in the backbone of subtype C, which has come from Indian subtype C.
PMCID: PMC3749696  PMID: 23742670
7.  Phylogenetic Analysis of Near Full-Length HIV Type 1 Genomic Sequences from 21 Korean Individuals 
The Korean subclade of subtype B (KSB) is the most prevalent HIV-1 strain found in Korea. To date, only two near full-length HIV-1 sequences from Korean patients have been reported. Here, we analyzed a total of 24 near full-length genomes of HIV-1 strains that were isolated from 17 antiretroviral therapy (ART)-naive patients and four ART-exposed patients. Proviral DNA from peripheral blood mononuclear cells was PCR amplified and directly sequenced. Phylogenetic analyses were used to classify viruses from 19 patients as KSB, from one patient as subtype B, from one patient as subtype D, and three viruses from one patient as CRF02_AG. All KSB viruses demonstrated TAAAA instead of TATAA at the TATA box in the LTR. Of the 19 KSB patients, their sequence identities at the nucleotide level ranged from 89.8% to 97.1% from the lowest env gene to the highest pol gene. Other than the CRF02_AG viruses, no recombination events were noted in any of the 19 KSB patients, which is consistent with our previous studies on the pol, vif, and nef genes. Except for one strain, all of the strains were classified as non-syncytium-inducing strains. This is the first report to describe near full-length KSB.
PMCID: PMC3607908  PMID: 23199052
8.  Short Communication Phylogenetic Characterization of HIV Type 1 CRF01_AE V3 Envelope Sequences in Pregnant Women in Northern Vietnam 
Characterization of HIV-1 strains is important for surveillance of the HIV-1 epidemic. In Vietnam HIV-1-infected pregnant women often fail to receive the care they are entitled to. Here, we analyzed phylogenetically HIV-1 env sequences from 37 HIV-1-infected pregnant women from Ha Noi (n=22) and Hai Phong (n=15), where they delivered in 2005–2007. All carried CRF01_AE in the gp120 V3 region. In 21 women CRF01_AE was also found in the reverse transcriptase gene. We compared their env gp120 V3 sequences phylogenetically in a maximum likelihood tree to those of 198 other CRF01_AE sequences in Vietnam and 229 from neighboring countries, predominantly Thailand, from the HIV-1 database. Altogether 464 sequences were analyzed. All but one of the maternal sequences colocalized with sequences from northern Vietnam. The maternal sequences had evolved the least when compared to sequences collected in Ha Noi in 2002, as shown by analysis of synonymous and nonsynonymous changes, than to other Vietnamese sequences collected earlier and/or elsewhere. Since the HIV-1 epidemic in women in Vietnam may still be underestimated, characterization of HIV-1 in pregnant women is important to observe how HIV-1 has evolved and follow its molecular epidemiology.
PMCID: PMC3399564  PMID: 21936713
9.  Changes in the Distribution of HIV Type 1 Subtypes D and A in Rakai District, Uganda Between 1994 and 2002 
AIDS Research and Human Retroviruses  2010;26(10):1087-1091.
HIV-1 subtype D (HIV-1D) progresses to disease faster and has lower transmissibility than subtype A (HIV-1A). We examined whether these differences could lead to a population level change in the distribution of these subtypes over time. HIV-1 viral RNA was extracted from stored serum samples from HIV-positive subjects participating in a population-based cohort study in Rakai, Uganda in 1994 and 2002. Portions of the viral proteins gag and gp41 were sequenced and subtyped. HIV-1 subtype assignments were generated for 773 subjects in 1994 and 812 subjects in 2002. The change in subtype distribution of the population as a whole as well as quartile age groups were examined for significant changes using a linear model. There was a significant decrease in the proportion of subjects infected with HIV-1D from 70.2% to 62.4% and a significant increase in subjects infected with HIV-1A from 16.7% to 23.3% over the 8-year period (p = 0.005). The most marked changes in proportion of HIV-1D and A were seen in the younger individuals (<25 and 25–30 years; p < 0.05). The percentages of subjects infected with HIV-1C and recombinant subtypes did not change significantly. Over this 8-year period, the overall viral population in this region evolved toward the less virulent HIV-1A strain, most likely as a consequence of the faster disease progression and lower transmissibility of HIV-1D.
PMCID: PMC2965693  PMID: 20925575
10.  The Analysis of Near Full-Length Genome Sequences of HIV Type 1 Subtype A Viruses from Russia Supports the Monophyly of Major Intrasubtype Clusters 
AIDS Research and Human Retroviruses  2012;28(10):1340-1343.
The HIV-1 epidemic in Russia has been insufficiently studied, with only 11 complete genome sequences from this country currently available, only three of which are of the locally predominant genetic form, the former Soviet Union (FSU) subtype A variant (AFSU). Here we analyze 10 newly derived AFSU near full-length genome sequences from Russia. Samples were selected based on phylogenetic clustering in protease-reverse transcriptase in two of the major AFSU clusters, V77IPR (n=6), widely circulating in Russia and other FSU countries, and ASP1 (n=4), predominant in St. Petersburg. The phylogenetic analysis shows that the V77IPR genomes group in a monophyletic cluster together with 10 previously obtained AFSU genome sequences from Uzbekistan, Kazakhstan, Russia, and Cyprus, all bearing the V77I substitution in protease. Similarly, the four ASP1 genomes group in a monophyletic cluster. These results therefore show that the monophyly of V77IPR and ASP1 AFSU clusters is supported in near complete genomes.
PMCID: PMC3448094  PMID: 22251084
11.  Emergence of a New HIV Type 1 CRF01_AE Variant in Guangxi, Southern China 
AIDS Research and Human Retroviruses  2012;28(10):1352-1356.
The distribution of HIV-1 subtypes and genetic characterization of CRF01_AE in Guangxi, southern China were identified. The distribution of HIV-1 genotypes based on gag, pol, and partial env sequences (n=349) was as follows: CRF01_AE (66.5%), CRF08_BC (19.2%), CRF07_BC (7.2%), URF (4.6%), subtype B (1.7%), and subtype B′ (0.9%). CRF01_AE predominated in all geographic regions and risk populations and there were multiple introductions of CRF01_AE strains in Guangxi. We found a peculiar CRF01_AE monophyletic lineage distinct from other CRF01_AE viruses, and we designated it “CRF01_AE-v” for convenience. CRF01_AE-v circulating in both heterosexuals and injecting drug users (IDUs) had accounted for 39.7% of CRF01_AE. It showed a selective advantage in the Guangxi population and formed its own characteristic compared with all the CRF01_AE references. Our results suggested that CRF01_AE-v was a new variant of CRF01_AE and it might lead to a new epidemic in Guangxi.
PMCID: PMC3448111  PMID: 22264007
12.  Identification of a Novel HIV Type 1 Circulating Recombinant Form (CRF52_01B) in Southeast Asia 
AIDS Research and Human Retroviruses  2012;28(10):1357-1361.
Thirty HIV-1 URF_01AE/ B′ complete or nearly full-length genome sequences sampled within Southeast Asia were obtained from the Los Alamos HIV Sequence Database. Phylogenetic and recombinant analyses revealed that three sequences indeed displayed the identical recombinant structure. Of note, the three subjects, harboring novel CRF01_AE/B recombinants, did not have apparent epidemiological linkage. They fulfilled the criteria for the designation of a new circulating recombinant form (CRF) and constituted the 52nd CRF identified in the worldwide HIV-1 pandemic. In this chimera, two short subtype B segments were inserted into a backbone of CRF_01AE. The breakpoints corresponded to HXB2 nucleotide positions 2930, 3251, 8521, and 9004 approximately. This CRF is the first one identified by neatening and analyzing the sequences already presented in the Los Alamos HIV Sequence Database. This indicates that we should pay attention not only to explicit subtype sequences but also to those classified as a unique recombinant form (URF) so far.
PMCID: PMC3448130  PMID: 22269007
13.  Short Communication: Molecular Epidemiology of HIV Type 1 Infection in Kazakhstan: CRF02_AG Prevalence Is Increasing in the Southeastern Provinces 
To analyze HIV-1 genetic variants in Kazakhstan, HIV-1 sequences were obtained from 205 antiretroviral-treated (ART) and naive patients in 2009–2013. Samples were collected in the most populous cities and provinces of Kazakhstan. On the basis of phylogenetic analyses of partial pol sequences, subtype A variant intravenous drug user (IDU)-A (which is dominant in the former Soviet Union) was found in 60.0% of the individuals, followed by CRF02_AG (34.6%); the rest of the samples were subtype B, CRF03_AB, CRF63_02A1, and CRF07_BC. The proportion of CRF02_AG has increased significantly since 2001–2003, when it was less than 5%. The majority of the CRF02_AG cases were found in Almaty, the former capital and the most populous city in Kazakhstan. The IDU-A variant dominated in the industrial regions of northern and central Kazakhstan and some other regions. Both dominant HIV-1 genetic variants were almost equally represented in the two main transmission groups: IDUs and heterosexuals. The analysis of drug-resistant mutations found a low prevalence of drug resistance in 165 therapy-naive individuals (3.0%). Thus, in the beginning of the second decade of the 2000s, the HIV epidemic in Kazakhstan is driven by two main genetic variants: IDU-A and CRF02_AG.
PMCID: PMC4118701  PMID: 24873898
14.  Identification of a Novel HIV Type 1 Circulating Recombinant Form (CRF65_cpx) Composed of CRF01_AE and Subtypes B and C in Western Yunnan, China 
A novel HIV-1 circulating recombinant form (CRF) designated CRF65_cpx was recently characterized from three epidemiologically unlinked individuals infected through heterosexual contact in western Yunnan province of China. This is the first complex mosaic HIV-1 CRF, consisting of contributions from three or more different subtypes, identified in China. An additional full-length genome sequence with identical recombinant breakpoints was found among a previously reported recombinant strain from a man who had sex with a man in Anhui province of East Central China. The breakpoint analysis of the recombinants showed a complex genome organization composed of parental subtypes B′ (Thailand variant of subtype B), C, and CRF01_AE, with 13 recombination breakpoints observed in almost all structure genes of HIV-1. The generation of complex recombinant forms is likely due to cocirculation of multiple lineages of HIV-1 strains in high-risk populations in western Yunnan.
PMCID: PMC4046203  PMID: 24279591
15.  Inability to Detect Human T Cell Lymphotropic Virus Type 2-Specific Antibodies in a Patient Coinfected with HIV-1, Human T Cell Lymphotropic Virus Type 1, Human T Cell Lymphotropic Virus Type 2, and Hepatitis C Virus 
HIV-1, human T cell lymphotropic virus type 1 and type 2 (HTLV-1 and HTLV-2) and hepatitis C virus (HCV) are common among intravenous drug users (IDUs) and can cause chronic infections in the host. Usually, the diagnosis of such viruses employs serological assays; however, some difficulties in confirming HTLV-2 infection have been reported in high-risk populations in Brazil. We present data of an unusual case of coinfection with HIV-1, HTLV-1, HTLV-2, and HCV in a male IDU in which HTLV-2 was detected only by molecular assays. Comparative analysis of retroviruses from 2002 and 2012 showed identical HTLV-1 and HTLV-2 sequences (LTR, env, and tax), and a change in HIV-1 tropism from CXCR4 to CCR5. No mutation was detected in the hot points of the env region of the HTLV-2 isolate that justified the lack of rgp46-II-specific antibodies. These data emphasize the need for molecular assays to diagnose HTLV-2 in high-risk populations in Brazil.
PMCID: PMC3887399  PMID: 23875602
16.  Short Communication: Effect of Short-Course Antenatal Zidovudine and Single-Dose Nevirapine on the BED Capture Enzyme Immunoassay Levels in HIV Type 1 Subtype C Infection 
Cross-sectional prevalence studies based on immunoassays that discriminate between recent and long-term infections, such as the BED assay, have been widely used to estimate HIV incidence. However, individuals receiving highly active antiretroviral therapy tend to have lower BED levels and are associated with a higher risk for being mistakenly classified as recent infections. To assess the effect of short-term antenatal zidovudine (ZDV) and single-dose nevirapine (sdNVP) on the BED levels in HIV-1C infection, we measured longitudinal BED normalized optical density (OD-n) levels using stored plasma samples collected prenatally and postnatally from 159 pregnant HIV-infected women in Botswana who participated in the randomized clinical Mother-to-Child-Prevention study, the Mashi study. All women received ZDV from 34 weeks gestation through delivery and were randomized to receive either sdNVP or placebo during labor. Among 159 subjects, the OD-n levels decreased from baseline to delivery in 93 subjects (p=0.039), suggesting that short-course ZDV may decrease OD-n levels. sdNVP at delivery did not affect longitudinal BED OD-n levels postdelivery. However, sdNVP appeared to modify the association between CD4 count at delivery and OD-n levels postdelivery. When estimating HIV incidence with the BED assay, special care may be required regarding women who received short-term ZDV for prevention of mother-to-child transmission.
PMCID: PMC3653368  PMID: 23521375
17.  No Increase of Drug-Resistant HIV Type 1 Prevalence Among Drug-Naive Individuals in Northern Vietnam 
AIDS Research and Human Retroviruses  2012;28(10):1349-1351.
We reported previously that the prevalence of drug-resistant HIV-1 among antiretroviral therapy (ART)-naive individuals in Northern Vietnam was 2.9% in 2007 and 6.2% in 2008. To investigate the continuing trend of prevalence, we collected plasma samples from 958 individuals in Hai Phong and Hanoi in 2009, extracted viral RNA from HIV-1 antibody-positive samples, and analyzed them genetically. HIV-1 antibody prevalence was 26.8% in injecting drug users (n=302), 13.4% in female sex workers (n=284), 0.5% in blood donors (n=206), and 0.6% in pregnant women (n=166). All HIV-1 strains were CRF01_AE. Nonnucleoside reverse-transcriptase inhibitor resistance mutations were found in two (2.0%) of the 102 successfully analyzed cases (one case with the Y181C and one with the K101E). No nucleoside reverse-transcriptase inhibitor resistance or protease inhibitor resistance mutations were detected. The prevalence of circulating ART-resistant HIV-1 in Northern Vietnam did not increase from 2007 to 2009, although the rate of ART coverage did increase.
PMCID: PMC3448096  PMID: 22264087
18.  Phylogenetic and Similarity Analysis of HTLV-1 Isolates from HIV-Coinfected Patients from the South and Southeast Regions of Brazil 
HTLV-1 is endemic in Brazil and HIV/HTLV-1 coinfection has been detected, mostly in the northeast region. Cosmopolitan HTLV-1a is the main subtype that circulates in Brazil. This study characterized 17 HTLV-1 isolates from HIV coinfected patients of southern (n=7) and southeastern (n=10) Brazil. HTLV-1 provirus DNA was amplified by nested PCR (env and LTR) and sequenced. Env sequences (705 bp) from 15 isolates and LTR sequences (731 bp) from 17 isolates showed 99.5% and 98.8% similarity among sequences, respectively. Comparing these sequences with ATK (HTLV-1a) and Mel5 (HTLV-1c) prototypes, similarities of 99% and 97.4%, respectively, for env and LTR with ATK, and 91.6% and 90.3% with Mel5, were detected. Phylogenetic analysis showed that all sequences belonged to the transcontinental subgroup A of the Cosmopolitan subtype, clustering in two Latin American clusters.
PMCID: PMC3252815  PMID: 21591992
19.  Distinct Circulating Recombinant HIV-1 Strains Among Injecting Drug Users and Sex Workers in Afghanistan 
Little information is available regarding a circulating HIV genotype among high-risk groups in Afghanistan; we describe HIV genotypes among injecting drug users (IDUs) and sex workers (SWs) in four Afghan cities. Participants completed behavioral questionnaires and HIV testing. Western blot–confirmed specimens had peripheral mononuclear blood cells isolated for genotyping. Analysis of recombinants was done by bootscanning and manual sequence alignment. The single SW sample harbored a CRF01_AE strain. Of 10 IDUs available for analysis, all were CRF35_AD and from Hirat. Analyzed subregions (gag p17 and env C1-C5) revealed close homology between the Hirat specimens. Three distinct subclusters comprising two or three strains were identified, whereas two other strains were generally equidistant from previously identified Kabul strains. Results suggest that the nascent HIV epidemic among IDUs in Hirat is largely, if not entirely, subtype CRF35_AD, and the close homology suggests recent infection; harm reduction should be supported to avert further transmission.
PMCID: PMC2933162  PMID: 20438383
20.  Complex Mosaic Composition of Near Full-Length Genomes of Two NED (NIH-ENVA-DOD) Subtype Panel HIV Type 1 Strains, BCF-Dioum and BCF-Kita, Originating from the Democratic Republic of Congo (DRC) 
AIDS Research and Human Retroviruses  2009;25(10):1039-1043.
Sequence characterization of the near full-length genomes of HIV-1 isolates BCF-Dioum and BCF-Kita, originating from the Democratic Republic of Congo (DRC), was continued. These NED panel isolates, contributed by F. Brun-Vezinet (ENVA-France), were first identified as subtypes G and H, respectively. Our earlier analyses of portions of their pol genes showed that both were likely to be intersubtype recombinants of different composition. This study analyzed the remainder of each genome, confirming them to be complex recombinants. The BCF-Dioum genome resembles CRF06_cpx strains found in West Africa, composed of subtypes A/G/J/K. The BCF-Kita genome is a unique complex recombinant A–F–G–H–K–U strain. These data support previous observations of the complexity of strains originating from the DRC. BCF-Dioum may be a suitable strain for standards and reagents since it matches a defined circulating recombinant form. Studies and reagents made from BCF-Kita should take into account its complex genome.
PMCID: PMC2828238  PMID: 19795987
21.  Genetic Analysis and Natural Polymorphisms in HIV-1 gp41 Isolates from Maputo City, Mozambique 
Enfuvirtide was the first fusion inhibitor approved by the Food and Drug Administration (FDA) in 2003 for HIV-1 infection in treatment-experienced patient. It is the first approved antiviral agent to attack the HIV life cycle in its early stages. For HIV fusion to occur, the HR1 and HR2 domains in the gp41 region need to interact. Enfuvirtide is a synthetic peptide that corresponds to 36 amino acids of the HR2, which competitively binds to HR1 inhibiting the interaction with the HR2 domain thus preventing fusogenic conformation and inhibiting viral entry into host cells. Resistance to enfuvirtide is conferred by mutations occurring in the HR1 region involving residues 36–45. Mozambique, a sub-Saharan country, with an HIV prevalence of 11.5%, provides first line and second line antiretroviral therapy (ART)-based treatment. In poor resource settings such as Mozambique the lack of adequate infrastructures, the high costs of viral load tests, and the availability of salvage treatment have hindered the intended objective of monitoring HIV treatment, suggesting an important concern regarding the development of drug resistance. The general aim of this study was to evaluate naturally occurring polymorphisms and resistance-associated mutations in the gp41 region of HIV-1 isolates from Mozambique. The study included 78 patients naive to ARV treatment and 28 patients failing first line regimen recruited from Centro de Saúde Alto-Maé situated in Maputo. The gp41 gene from 103 patients was sequenced and resistance-associated mutations for enfuvirtide were screened. Subtype analysis revealed that 96% of the sequences were classified as subtype C, 2% as subtype G, 1% as subtype A1, and the other 1% as a mosaic form composed of A1/C. No enfuvirtide resistance-associated mutations in HR1 of gp41 were detected. The major polymorphisms in the HR1 were N42S, L54M, A67T, and V72I. This study suggests that this new class of antiviral drug may be effective as a salvage therapy in patients failing first line regimens in Mozambique. However, further phenotypic studies are required to determine the clinical relevance of the polymorphisms detected in this study.
PMCID: PMC4046211  PMID: 24188582
22.  Viral Tropism and Antiretroviral Drug Resistance in HIV-1 Subtype C-Infected Patients Failing Highly Active Antiretroviral Therapy in Johannesburg, South Africa 
Reports show that up to 30% of antiretroviral drug-naive patients in Johannesburg have CXCR4-utilizing HIV-1 subtype C. We assessed whether HIV-1 subtype C-infected individuals failing highly active antiretroviral therapy (HAART) have a higher proportion of CXCR4-utilizing viruses compared to antiretroviral drug-naive patients. The V3 loop was sequenced from plasma from 100 randomly selected HAART-failing patients, and tropism was established using predictive algorithms. All patients harbored HIV-1 subtype C with at least one antiretroviral drug resistance mutation. Viral tropism prediction in individuals failing HAART revealed similar proportions (29%) of X4-utilizing viruses compared to antiretroviral drug-naive patients (30%). Findings are in contrast to reports from Durban in which 60% of HAART-failing subjects harbored X4/dual/mixed-tropic viruses. Despite differences in proportions of X4-tropism within South Africa, the high proportion of thymidine analogue mutations (TAMs) and CXCR4-utilizing HIV-1 highlights the need for intensified monitoring of HAART patients and the predicament of diminishing drug options, including CCR5 antagonists, for patients failing therapy.
PMCID: PMC3938925  PMID: 24224886
23.  Short Communication: Defining Optimality of a Test for Recent Infection for HIV Incidence Surveillance 
The estimation of HIV incidence from cross-sectional surveys using tests for recent infection has attracted much interest. It is increasingly recognized that the lack of high performance recent infection tests is hindering the implementation of this surveillance approach. With growing funding opportunities, test developers are currently trying to fill this gap. However, there is a lack of consensus and clear guidance for developers on the evaluation and optimization of candidate tests. A fundamental shift from conventional thinking about test performance is needed: away from metrics relevant in typical public health settings where the detection of a condition in individuals is of primary interest (sensitivity, specificity, and predictive values) and toward metrics that are appropriate when estimating a population-level parameter such as incidence (accuracy and precision). The inappropriate use of individual-level diagnostics performance measures could lead to spurious assessments and suboptimal designs of tests for incidence estimation. In some contexts, such as population-level application to HIV incidence, bias of estimates is essentially negligible, and all that remains is the maximization of precision. The maximization of the precision of incidence estimates provides a completely general criterion for test developers to assess and optimize test designs. Summarizing the test dynamics into the properties relevant for incidence estimation, high precision estimates are obtained when (1) the mean duration of recent infection is large, and (2) the false-recent rate is small. The optimal trade-off between these two test properties will produce the highest precision, and therefore the most epidemiologically useful incidence estimates.
PMCID: PMC3887426  PMID: 24090052
24.  Subtype B Was the Dominant Strain Among HIV Type 1 Infections Except for the Population of Men Who Have Sex with Men in Harbin City, China 
AIDS Research and Human Retroviruses  2013;29(9):1260-1264.
We sought to identify the prevalent subtypes and study the genetic variation of HIV-1 circulating in HIV infections in Harbin City, China. Forty-seven samples from the env V3-V4 region were successfully sequenced and analyzed, which involved thirty-one men who have sex with men (MSM), eight heterosexuals, seven former plasma donors (FPD)/blood transfusion recipients (BT), and one injection drug user (IDU). In all, 46.8% of CRF01_AE, 40.4% of subtype B, and 12.8% of CRF07_BC were identified. CRF01_AE (64.5%) was the dominant strain in MSM, and subtype B (81.2%) was the chief strain in other infected subjects except for the MSM population. Among all the genotypes, the B subtype possesses greater diversity of the tetramer on the tip of V3 loop than CRF07_BC and CRF01_AE, in which the peculiar GWGR was commonly found. Because nationwide there is a trend toward the increasing presence of CRF01_AE, a consecutive surveillance campaign was necessary among all HIV vulnerable populations in this locality.
PMCID: PMC3749703  PMID: 23734595
25.  Differential Specificity of HIV Incidence Assays in HIV Subtypes A and D-Infected Individuals from Rakai, Uganda 
AIDS Research and Human Retroviruses  2013;29(8):1146-1150.
Assays to determine HIV incidence from cross-sectional surveys have exhibited a high rate of false-recent misclassification in Kenya and Uganda where HIV subtypes A and D predominate. Samples from individuals infected with HIV for at least 2 years with known infecting subtype (133 subtype A, 373 subtype D) were tested using the BED-CEIA and an avidity assay. Both assays had a higher rate of false-recent misclassification for subtype D compared to subtype A (13.7% vs. 6.0%, p=0.02 for BED-CEIA; 11.0% vs. 1.5%, p<0.001 for avidity). For subtype D samples, false-recent misclassification by the BED-CEIA was also more frequent in women than men (15.0% vs. 5.6%, p=0.002), and for samples where that had an amino acid other than lysine at position 12 in the BED-CEIA peptide coding region (p=0.002). Furthermore in subtype D-infected individuals, samples misclassified by one assay were 3.5 times more likely to be misclassified by the other assay. Differential misclassification by infecting subtype of long-term infected individuals as recently infected makes it difficult to use these assays individually to estimate population level incidence without precise knowledge of the distribution of these subtypes within populations where subtype A and D cocirculate. The association of misclassification of the BED-CEIA with the avidity assay in subtype D-infected individuals limits the utility of using these assays in combination within this population.
PMCID: PMC3715796  PMID: 23641870

Results 1-25 (887)