10 research outputs found
Prevalence of sexually transmitted infections among men who have sex with men in Zagreb, Croatia.
We used respondent-driven sampling among men who have sex with men (MSM) in Zagreb, Croatia in 2006 to investigate the prevalence of HIV, other sexually transmitted infections and sexual behaviours. We recruited 360 MSM. HIV infection was diagnosed in 4.5%. The seroprevalence of antibodies to viral pathogens was: herpes simplex virus type-2, 9.4%; hepatitis A, 14.2%; hepatitis C, 3.0%. Eighty percent of participants were susceptible to HBV infection (HBs antigen negative, and no antibodies to HBs and HBc antigen). Syphilis seroprevalence was 10.6%. Prevalence of Chlamydia and gonorrhoea was 9.0%, and 13.2%, respectively. Results indicate the need for interventions to diagnose, treat and prevent sexually transmitted infections among this population
Global Genomic Diversity of Human Papillomavirus 6 Based on 724 Isolates and 190 Complete Genome Sequences.
Human papillomavirus type 6 (HPV6) is the major etiological agent of anogenital warts and laryngeal papillomas and has been included in both the quadrivalent and nonavalent prophylactic HPV vaccines. This study investigated the global genomic diversity of HPV6, using 724 isolates and 190 complete genomes from six continents, and the association of HPV6 genomic variants with geographical location, anatomical site of infection/disease, and gender. Initially, a 2,800-bp E5a-E5b-L1-LCR fragment was sequenced from 492/530 (92.8%) HPV6-positive samples collected for this study. Among them, 130 exhibited at least one single nucleotide polymorphism (SNP), indel, or amino acid change in the E5a-E5b-L1-LCR fragment and were sequenced in full. A global alignment and maximum likelihood tree of 190 complete HPV6 genomes (130 fully sequenced in this study and 60 obtained from sequence repositories) revealed two variant lineages, A and B, and five B sublineages: B1, B2, B3, B4, and B5. HPV6 (sub)lineage-specific SNPs and a 960-bp representative region for whole-genome-based phylogenetic clustering within the L2 open reading frame were identified. Multivariate logistic regression analysis revealed that lineage B predominated globally. Sublineage B3 was more common in Africa and North and South America, and lineage A was more common in Asia. Sublineages B1 and B3 were associated with anogenital infections, indicating a potential lesion-specific predilection of some HPV6 sublineages. Females had higher odds for infection with sublineage B3 than males. In conclusion, a global HPV6 phylogenetic analysis revealed the existence of two variant lineages and five sublineages, showing some degree of ethnogeographic, gender, and/or disease predilection in their distribution.
IMPORTANCE: This study established the largest database of globally circulating HPV6 genomic variants and contributed a total of 130 new, complete HPV6 genome sequences to available sequence repositories. Two HPV6 variant lineages and five sublineages were identified and showed some degree of association with geographical location, anatomical site of infection/disease, and/or gender. We additionally identified several HPV6 lineage- and sublineage-specific SNPs to facilitate the identification of HPV6 variants and determined a representative region within the L2 gene that is suitable for HPV6 whole-genome-based phylogenetic analysis. This study complements and significantly expands the current knowledge of HPV6 genetic diversity and forms a comprehensive basis for future epidemiological, evolutionary, functional, pathogenicity, vaccination, and molecular assay development studies
Immune-Escape Mutations and Stop-Codons in HBsAg Circulates in a Relevant Proportion of Patients with Chronic HBV Infection Exposed to Anti-HBV Drugs in Europe: Implications for HBV Transmission in the Setting of Vaccination and Disease Progression
Duality between N=1 supersymmetric gauge theories(Seiberg's duality) isgeometrized, in the framework of AdS/CFT correspodences. It is shown thatSeiberg's duality corresponds to monodromy of wrapped D5 branes on the homologycycles of a generalized conifold where D3 branes are located. The celebrated\tilde{N}_c=N_f-N_c, \tilde{N}_f=N_f rule is reproduced and a braid groupstructure in a sequence of dualities, is found
Primary resistance to integrase strand-transfer inhibitors in Europe
Objectives: The objective of this study was to define the natural genotypic variation of the HIV-1 integrase gene
across Europe for epidemiological surveillance of integrase strand-transfer inhibitor (InSTI) resistance.
Methods: This was a multicentre, cross-sectional study within the European SPREAD HIV resistance surveillance
programme. A representative set of 300 samples was selected from 1950 naive HIV-positive subjects newly diagnosed
in 2006–07. The prevalence of InSTI resistance was evaluated using quality-controlled baseline population
sequencing of integrase. Signature raltegravir, elvitegravir and dolutegravir resistance mutations were
defined according to the IAS-USA 2014 list. In addition, all integrase substitutions relative to HXB2 were identified,
including those with a Stanford HIVdb score ≥10 to at least one InSTI. To rule out circulation of minority InSTIresistant
HIV, 65 samples were selected for 454 integrase sequencing.
Results: For the population sequencing analysis, 278 samples were retrieved and successfully analysed. No signature
resistance mutations to any of the InSTIswere detected. Eleven (4%) subjects hadmutations at resistance-associated
positions with an HIVdb score ≥10. Of the 56 samples successfully analysed with 454 sequencing, no InSTI signature
mutationsweredetected,whereas integrase substitutionswithanHIVdbscore≥10were found in8(14.3%) individuals.
Conclusions:No signature InSTI-resistant variantswere circulating in Europe before the introduction of InSTIs. However,
polymorphisms contributing to InSTI resistancewere not rare. As InSTI use becomes more widespread, continuous surveillance
of primary InSTI resistance is warranted. These data will be key to modelling the kinetics of InSTI resistance
transmission in Europe in the coming years
European guidelines on the clinical management of HIV-1 tropism testing
Viral tropism is the ability of viruses to enter and infect specific
host cells and is based on the ability of viruses to bind to receptors
on those cells. Testing for HIV tropism is recommended before
prescribing a chemokine receptor blocker. In most European countries,
HIV tropism is identified with tropism phenotype testing. New data
support genotype analysis of the HIV third hypervariable loop (V3) for
the identification of tropism. The European Consensus Group on clinical
management of tropism testing was established to make recommendations to
clinicians and clinical virologists. The panel recommends HIV-tropism
testing for the following groups: drug-naive patients in whom toxic
effects are anticipated or for whom few treatment options are available;
patients who have poor tolerability to or toxic effects from current
treatment or who have CNS pathology; and patients for whom therapy has
failed and a change in treatment is considered. In general, an enhanced
sensitivity Trofile assay and V3 population genotyping are the
recommended methods. Genotypic methods are anticipated to be used more
frequently in the clinical setting because of their greater
accessibility, lower cost, and faster turnaround time than other
methods. For the interpretation of V3 loop genotyping, clinically
validated systems should be used when possible. Laboratories doing HIV
tropism tests should have adequate quality assurance measures.
Similarly, close collaboration between HIV clinicians and virologists is
needed to ensure adequate diagnostic and treatment decisions
Primary resistance to integrase strand-transfer inhibitors in Europe
Objectives: The objective of this study was to define the natural genotypic variation of the HIV-1 integrase gene across Europe for epidemiological surveillance of integrase strand-transfer inhibitor (InSTI) resistance. Methods: This was a multicentre, cross-sectional study within the European SPREAD HIV resistance surveillance programme. A representative set of 300 samples was selected from 1950 naive HIV-positive subjects newly diagnosed in 2006-07. The prevalence of InSTI resistance was evaluated using quality-controlled baseline population sequencing of integrase. Signature raltegravir, elvitegravir and dolutegravir resistance mutations were defined according to the IAS-USA 2014 list. In addition, all integrase substitutions relative to HXB2 were identified, including those with a Stanford HIVdb score=10 to at least one InSTI. To rule out circulation of minority InSTIresistant HIV, 65 samples were selected for 454 integrase sequencing. Results: For the population sequencing analysis, 278 samples were retrieved and successfully analysed. No signature resistance mutations to any of the InSTIswere detected. Eleven (4%) subjects hadmutations at resistance-associated positions with an HIVdb score =10. Of the 56 samples successfully analysed with 454 sequencing, no InSTI signature mutationsweredetected, whereas integrase substitutionswithanHIVdbscore=10were found in8(14.3%) individuals. Conclusions:No signature InSTI-resistant variantswere circulating in Europe before the introduction of InSTIs. However, polymorphisms contributing to InSTI resistancewere not rare. As InSTI use becomes more widespread, continuous surveillance of primary InSTI resistance is warranted. These data will be key to modelling the kinetics of InSTI resistance transmission in Europe in the coming years. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved
Transmission of HIV drug resistance and the predicted effect on current first-line regimens in Europe
Background. Numerous studies have shown that baseline drug resistance patterns may influence the outcome of antiretroviral therapy. Therefore, guidelines recommend drug resistance testing to guide the choice of initial regimen. In addition to optimizing individual patient management, these baseline resistance data enable transmitted drug resistance (TDR) to be surveyed for public health purposes. The SPREAD program systematically collects data to gain insight into TDR occurring in Europe since 2001. Methods. Demographic, clinical, and virological data from 4140 antiretroviral-naive human immunodeficiency virus (HIV)-infected individuals from 26 countries who were newly diagnosed between 2008 and 2010 were analyzed. Evidence of TDR was defined using the WHO list for surveillance of drug resistance mutations. Prevalence of TDR was assessed over time by comparing the results to SPREAD data from 2002 to 2007. Baseline susceptibility to antiretroviral drugs was predicted using the Stanford HIVdb program version 7.0. Results. The overall prevalence of TDR did not change significantly over time and was 8.3% (95% confidence interval, 7.2%-9.5%) in 2008-2010. The most frequent indicators of TDR were nucleoside reverse transcriptase inhibitor (NRTI) mutations (4.5%), followed by nonnucleoside reverse transcriptase inhibitor (NNRTI) mutations (2.9%) and protease inhibitor mutations (2.0%). Baseline mutations were most predictive of reduced susceptibility to initial NNRTI-based regimens: 4.5% and 6.5% of patient isolates were predicted to have resistance to regimens containing efavirenz or rilpivirine, respectively, independent of current NRTI backbones. Conclusions. Although TDR was highest for NRTIs, the impact of baseline drug resistance patterns on susceptibility was largest for NNRTIs. The prevalence of TDR assessed by epidemiological surveys does not clearly indicate to what degree susceptibility to different drug classes is affected