| 1. |
- Abidi, Syed Hani, et al.
(författare)
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Phylogenetic and Drug-Resistance Analysis of HIV-1 Sequences From an Extensive Paediatric HIV-1 Outbreak in Larkana, Pakistan
- 2021
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Ingår i: Frontiers in Microbiology. - : Frontiers Media SA. - 1664-302X. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: In April 2019, an HIV-1 outbreak among children occurred in Larkana, Pakistan, affecting more than a thousand children. It was assumed that the outbreak originated from a single source, namely a doctor at a private health facility. In this study, we performed subtype distribution, phylogenetic and drug-resistance analysis of HIV-1 sequences from 2019 outbreak in Larkana, Pakistan. Methods: A total of 401 blood samples were collected between April–June 2019, from children infected with HIV-1 aged 0–15 years recruited into a case-control study to investigate the risk factors for HIV-1 transmission. Partial HIV-1 pol sequences were generated from 344 blood plasma samples to determine HIV-1 subtype and drug resistance mutations (DRM). Maximum-likelihood phylogenetics based on outbreak and reference sequences was used to identify transmission clusters and assess the relationship between outbreak and key population sequences between and within the determined clusters. Bayesian analysis was employed to identify the time to the most recent common recent ancestor (tMRCA) of the main Pakistani clusters. Results: The HIV-1 circulating recombinant form (CRF) 02_AG and subtype A1 were most common among the outbreak sequences. Of the treatment-naïve participants, the two most common mutations were RT: E138A (8%) and RT: K219Q (8%). Four supported clusters within the outbreak were identified, and the median tMRCAs of the Larkana outbreak sequences were estimated to 2016 for both the CRF02_AG and the subtype A1 clusters. Furthermore, outbreak sequences exhibited no phylogenetic mixing with sequences from other high-risk groups of Pakistan. Conclusion: The presence of multiple clusters indicated a multi-source outbreak, rather than a single source outbreak from a single health practitioner as previously suggested. The multiple introductions were likely a consequence of ongoing transmission within the high-risk groups of Larkana, and it is possible that the so-called Larkana strain was introduced into the general population through poor infection prevention control practices in healthcare settings. The study highlights the need to scale up HIV-1 prevention programmes among key population groups and improving infection prevention control in Pakistan.
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| 2. |
- Andersson, E., et al.
(författare)
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Increase in transmitted drug resistance in migrants from sub-Saharan Africa diagnosed with HIV-1 in Sweden
- 2018
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Ingår i: AIDS. - 0269-9370. ; 32:7, s. 877-884
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To study the trends of transmitted drug resistance (TDR) in HIV-1 patients newly diagnosed in Sweden, 2010-2016. Design: Register-based study including all antiretroviral therapy-naive patients ≥18 years diagnosed with HIV-1 in Sweden 2010-2016. Methods: Patient data and viral pol sequences were extracted from the national InfCareHIV database. TDR was defined as the presence of surveillance drug resistance mutations (SDRMs). A CD4+ T-cell decline trajectory model estimated time of infection. Phylogenetic inference was used for cluster analysis. Chi-square tests and logistic regressions were used to investigate relations between TDR, epidemiological and viral factors. Results: One thousand, seven hundred and thirteen pol sequences were analyzed, corresponding to 71% of patients with a new HIV-1 diagnosis (heterosexuals: 53%; MSM: 34%). The overall prevalence of TDR was 7.1% (95% CI 5.8-8.3%). Nonnucleoside reverse transcriptase inhibitor (NNRTI) TDR increased significantly from 1.5% in 2010 to 6.2% in 2016, and was associated to infection and/or origin in sub-Saharan Africa (SSA). An MSM transmission cluster dating back to the 1990s with the M41L SDRM was identified. Twenty-five (1.5%) patients exhibited TDR to tenofovir (TDF; n = 8), emtricitabine/lamivudine (n = 9) or both (n = 8). Conclusion: NNRTI TDR has increased from 2010 to 2016 in HIV-1-infected migrants from SSA diagnosed in Sweden, mirroring the situation in SSA. TDR to tenofovir/emtricitabine, used in preexposure prophylaxis, confirms the clinical and epidemiological need for resistance testing in newly diagnosed patients.
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| 3. |
- Andrews, Sophie M., et al.
(författare)
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Analysis of HIV-1 envelope evolution suggests antibody-mediated selection of common epitopes among Chinese former plasma donors from a narrow-source outbreak
- 2018
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- The HIV-1 envelope mutates rapidly to evade recognition and killing, and is a major target of humoral immune responses and vaccine development. Identification of common epitopes for vaccine development have been complicated by genetic variation on both virus and host levels. We studied HIV-1 envelope gp120 evolution in 12 Chinese former plasma donors infected with a purportedly single founder virus, with the aim of identifying common antibody epitopes under immune selection. We found five amino acid sites under significant positive selection in ≥50% of the study participants, and 22 sites consistent with antibody-mediated selection. Despite strong selection pressure, some sites housed a limited repertoire of amino acids. Structural modelling revealed that most of the variable amino acid sites were located on the exposed distal edge of the Gp120 trimer, whilst invariant sites clustered within the centre of the protein complex. Two sites, flanking the V3 hypervariable loop, represent novel antibody sites. Analysis of HIV-1 evolution in hosts infected with a narrow-source virus may provide insight and novel understanding of common epitopes under antibody-mediated selection. If verified in functional studies, such epitopes could be suitable as targets in vaccine development.
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| 4. |
- Boswell, Michael T., et al.
(författare)
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TRIM22 genotype is not associated with markers of disease progression in children with HIV-1 infection
- 2021
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Ingår i: AIDS (London, England). - 1473-5571. ; 35:15, s. 2445-2450
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Untreated perinatal HIV-1 infection is often associated with rapid disease progression in children with HIV (CWH), characterized by high viral loads and early mortality. TRIM22 is a host restriction factor, which directly inhibits HIV-1 transcription, and its genotype variation is associated with disease progression in adults. We tested the hypothesis that TRIM22 genotype is associated with disease progression in CWH. DESIGN: ART-naive CWH, aged 6-16 years, were recruited from primary care clinics in Harare, Zimbabwe. We performed a candidate gene association study of TRIM22 genotype and haplotypes with markers of disease progression and indicators of advanced disease. METHODS: TRIM22 exons three and four were sequenced by Sanger sequencing and single nucleotide polymorphisms were associated with markers of disease progression (CD4+ T-cell count and HIV viral load) and clinical indicators of advanced HIV disease (presence of stunting and chronic diarrhoea). Associations were tested using multivariate linear and logistic regression models. RESULTS: A total of 241 children, median age 11.4 years, 50% female, were included. Stunting was present in 16% of participants. Five SNPs were analyzed including rs7935564, rs2291842, rs78484876, rs1063303 and rs61735273. The median CD4+ count was 342 (IQR: 195-533) cells/μl and median HIV-1 viral load 34 199 (IQR: 8211-90 662) IU/ml. TRIM22 genotype and haplotypes were not associated with CD4+ T-cell count, HIV-1 viral load, stunting or chronic diarrhoea. CONCLUSION: TRIM22 genotype was not associated with markers of HIV disease progression markers or advanced disease in CWH.
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| 6. |
- Ederth, Josefine, et al.
(författare)
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Molecular characterization of HCV in a Swedish county over 8 years (2002-2009) reveals distinct transmission patterns.
- 2016
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Ingår i: Infection ecology & epidemiology. - : Informa UK Limited. - 2000-8686. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Hepatitis C virus (HCV) is a major public health concern and data on its molecular epidemiology in Sweden is scarce. We carried out an 8-year population-based study of newly diagnosed HCV cases in one of Sweden's centrally situated counties, Södermanland (D-county). The aim was to characterize the HCV strains circulating, analyze their genetic relatedness to detect networks, and in combination with demographic data learn more about transmission.
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| 9. |
- Esbjörnsson, Joakim, et al.
(författare)
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Frequent CXCR4 tropism of HIV-1 subtype A and CRF02_AG during late-stage disease - indication of an evolving epidemic in West Africa
- 2010
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Ingår i: Retrovirology. - : Springer Science and Business Media LLC. - 1742-4690. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Background: HIV-1 is one of the fastest evolving pathogens, and is distinguished by geographic and genetic variants that have been classified into different subtypes and circulating recombinant forms (CRFs). Early in infection the primary coreceptor is CCR5, but during disease course CXCR4-using HIV-1 populations may emerge. This has been correlated with accelerated disease progression in HIV-1 subtype B. Basic knowledge of HIV-1 coreceptor tropism is important due to the recent introduction of coreceptor antagonists in antiretroviral therapy, and subtype-specific differences regarding how frequently HIV-1 CXCR4-using populations appear in late-stage disease need to be further investigated. To study how frequently CXCR4-using populations appear in late-stage disease among HIV-1 subtype A and CRF02_AG, we evaluated the accuracy of a recombinant virus phenotypic assay for these subtypes, and used it to determine the HIV-1 coreceptor tropism of plasma samples collected during late-stage disease in Guinea-Bissau. We also performed a genotypic analysis and investigated subtype-specific differences in the appearance of CXCR4 tropism late in disease. Results: We found that the recombinant virus phenotypic assay accurately predicted HIV-1 coreceptor tropism of subtype A and CRF02_AG. Over the study period (1997-2007), we found an increasing and generally high frequency of CXCR4 tropism (86%) in CRF02_AG. By sequence analysis of the V3 region of our samples we developed a novel genotypic rule for predicting CXCR4 tropism in CRF02_AG, based on the combined criteria of the total number of charged amino acids and net charge. This rule had higher sensitivity than previously described genotypic rules and may be useful for development of future genotypic tools for this CRF. Finally, we conducted a literature analysis, combining data of 498 individuals in late-stage disease, and found high amounts of CXCR4 tropism for all major HIV-1 subtypes (60-77%), except for subtype C (15%). Conclusions: The increase in CXCR4 tropism over time suggests an evolving epidemic of CRF02_AG. The results of the literature analysis demonstrate the need for further studies investigating subtype-specific emergence for CXCR4-tropism; this may be particularly important due to the introduction of CCR5-antagonists in HIV treatment regimens.
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| 10. |
- Esbjörnsson, Joakim
(författare)
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HIV-1 evolution, disease progression and molecular epidemiology of HIV-1 single and HIV-1 and HIV-2 dual-infected individuals in Guinea-Bissau
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The two genetically related human lentiviruses known today, HIV-1 (which is pandemic) and HIV-2 (which mainly is confined to West Africa), are the causative agents of AIDS. Progressive immune dysfunction and AIDS develop in most cases of untreated HIV-1 infection, but only in approximately 25-30% of HIV-2 infected individuals. The V1-V3 region of the HIV-1 env gp120 is important for HIV-1 coreceptor use, and represents an informative region for both molecular epidemiology and intrapatient phylogenetic analyses due to high level of genetic variation. In this doctoral dissertation, HIV-1 V1-V3 sequences in combination with clinical disease markers were used to investigate HIV-1 evolution, disease progression, coreceptor tropism and molecular epidemiology of HIV-1. All sequences were derived from single (HIV-1 only) or dual-infected (HIV-1 and HIV-2) individuals from Guinea-Bissau, West Africa. The main findings was that CRF02_AG represents the most common form of HIV-1 in Guinea-Bissau, and that HIV-1 was introduced into the country on at least six different occasions between 1976 and 1981. Dual-infected individuals had a 46% lower mortality rate and a 53% longer progression-time to AIDS compared to single-infected individuals. CD4+ T cell counts were higher at corresponding time-points after infection among dual-infected individuals, reflecting the slower disease progression rate at the cellular immune level. In addition, CD8+ T cell counts were increasing at a faster rate in single than in dual-infected individuals. Stratified analyses showed that these observations were most prominent among the subgroup of dual-infected individuals that became HIV-1 infected after an established HIV-2 infection. Moreover, the HIV-1 genetic diversity was significantly lower in dual than in single-infected individuals at comparable time-points after infection. HIV-1 coreceptor tropism was investigated in late-stage disease by the use of a recombinant virus phenotypic assay that were confirmed to accurately predict the coreceptor tropism of HIV-1 subtype A and CRF02_AG. CXCR4 tropism has been coupled to an increased HIV-1 disease progression rate in late-stage disease. We found that HIV-1 CRF02_AG CXCR4 tropism was frequent (86%) and increased over time on the population level, indicating an evolving epidemic. In addition, a literature analysis showed a similar evolving epidemic for HIV-1 subtype C. Genotypic analysis suggested that the total number of charged amino acids could be important in predicting HIV-1 CRF02_AG coreceptor tropism. Finally, HIV-1 CXCR4-tropism was more common in single (79%) than in dual-infected individuals (35%). Understanding the underlying mechanisms responsible for the inhibitory effects exerted by HIV-2 against HIV-1 could be important for the development of future HIV-1 vaccines and therapeutics.
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