| 1. |
- Biague, Antonio Jaime, et al.
(författare)
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High sexual risk taking and diverging trends of HIV-1 and HIV-2 in the military of Guinea Bissau
- 2011
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Ingår i: Journal of Infection in Developing Countries. ; 5:4, s. 301-308
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: HIV and other sexually transmitted infections are a growing problem in the military personnel of Africa, and information about this problem in Guinea-Bissau is lacking. The aims of this study were to determine the prevalence and trends of the HIV epidemics in the military forces of Guinea Bissau and to explore possible risk factors for HIV infection. METHODOLOGY: Repeated cross-sectional surveys of HIV-1 and HIV-2 were conducted between 1992 and 2005, and knowledge, sexual behaviour and risk factors for HIV-1 and HIV-2 in military personnel in Guinea-Bissau were assessed. RESULTS: The seroprevalence of HIV-1, HIV-2 and HIV-1+HIV-2 dual reactivity was 1.1%, 8.4% and 0.1% in 1992-95, and in 2005 7.7%, 5.1% and 1.9%, respectively. Both the increase of HIV-1 and the decline of HIV-2 between 1992-95 and 2005 were significant when adjusted for age (p < 0.001 for both changes). Only a minority did not know how HIV transmits, but sexual risk taking was high. Several significant risk factors were found in univariate analyses for HIV-1 and HIV-2, but the only risk factor that remained significant after multivariate regression analysis was previous contact with a prostitute among HIV-1-positive subjects (single and dually reactive) (p < 0.01). CONCLUSION: The increasing trend of HIV-1 and the high risky sexual behavior illustrate the need for improvement in HIV/AIDS prevention efforts among military personnel in Guinea Bissau.
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| 2. |
- Bjerregaard-Andersen, Morten, et al.
(författare)
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Tuberculosis burden in an urban population: a cross sectional tuberculosis survey from Guinea Bissau
- 2010
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Ingår i: BMC Infectious Diseases. - : Springer Science and Business Media LLC. - 1471-2334. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Background: Little is known about the prevalence of pulmonary tuberculosis (TB) in low income countries. We conducted a cross sectional survey for pulmonary TB and TB symptoms in Bissau, Guinea-Bissau, in an urban cohort with known HIV prevalence. TB surveillance in the area is routinely based on passive case finding. Methods: Two cohorts were selected based on a previous HIV survey, but only 52.5% of those enrolled in the adult cohort had participated in the HIV survey. One cohort included all adults living in 384 randomly selected houses; in this cohort 8% (135/1687) were HIV infected. The other included individuals 50 years or older from all other houses in the study area; of these 11% (62/571) were HIV infected. Symptom screening was done through household visits using a standardised questionnaire. TB suspects were investigated with sputum smear microscopy and X-ray. Results: In the adult cohort, we found 4 cases among 2989 individuals screened, giving a total TB prevalence of 134/100,000 (95% CI 36-342/100,000). In the >50 years cohort, we found 4 cases among 571 individuals screened, giving a total prevalence of 701/100,000 (191-1784/100.000). Two of the eight detected TB cases were unknown by the TB program. Of the total TB cases five were HIV uninfected while three had unknown HIV status. The prevalence of TB symptoms was 2.1% (63/2989) and 10.3% (59/571) in the two cohorts respectively. Conclusions: In conclusion we found a moderately high prevalence of pulmonary TB and TB symptoms in the general population, higher among elderly individuals. By active case finding unknown cases were detected. Better awareness of TB and its symptoms needs to be promoted in low income settings.
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| 3. |
- Borggren, Marie, et al.
(författare)
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Neutralizing Antibody Response and Antibody-Dependent Cellular Cytotoxicity in HIV-1-Infected Individuals from Guinea-Bissau and Denmark
- 2016
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Ingår i: AIDS Research and Human Retroviruses. - : Mary Ann Liebert Inc. - 0889-2229 .- 1931-8405. ; 32:5, s. 434-442
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Tidskriftsartikel (refereegranskat)abstract
- The development of therapeutic and prophylactic HIV vaccines for African countries is urgently needed, but the question of what immunogens to use needs to be answered. One approach is to include HIV envelope immunogens derived from HIV-positive individuals from a geographically concentrated epidemic with more limited viral genetic diversity for a region-based vaccine. To address if there is a basis for a regional selected antibody vaccine, we have screened two regionally separate cohorts from Guinea-Bissau and Denmark for neutralizing antibody activity and antibody-dependent cellular cytotoxicity (ADCC) against local and nonlocal circulating HIV-1 strains. The neutralizing activity did not demonstrate higher potential against local circulating strains according to geography and subtype determination, but the plasma from Danish individuals demonstrated significantly higher inhibitory activity than that from Guinea-Bissau individuals against both local and nonlocal virus strains. Interestingly, an opposite pattern was observed with ADCC activity, where Guinea-Bissau individual plasma demonstrated higher activity than Danish plasma and was specifically against the local circulating subtype. Thus, on basis of samples from these two cohorts, no local-specific neutralizing activity was detected, but a local ADCC response was identified in the Guinea-Bissau samples, suggesting potential use of regional immunogens for an ADCC-inducing vaccine.
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| 4. |
- da Silva, Zacarias, et al.
(författare)
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Decline in human T-cell lymphotropic virus-1 prevalence in urban areas of Bissau, Guinea-Bissau: exploring the association with HIV infections.
- 2009
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Ingår i: AIDS. - 1473-5571. ; 23, s. 637-639
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Tidskriftsartikel (refereegranskat)abstract
- In 2006, a cross-sectional survey of 384 randomly selected houses within a community-based follow-up study was conducted to assess the human T-cell lymphotropic virus (HTLV) prevalence in Bissau. Changes in prevalence and incidence rates were assessed based on a similar survey carried out 10 years earlier. The prevalence of HTLV-1 declined significantly from 3.5% in 1996 to 2.3% in 2006. The incidence between 1996 and 2006 was only 0.9/1000 person-years and tended to be higher for women than for men.
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| 5. |
- da Silva, Zacarias J., et al.
(författare)
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Changes in prevalence and incidence of HIV-1, HIV-2 and dual infections in urban areas of Bissau, Guinea-Bissau : is HIV-2 disappearing?
- 2008
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Ingår i: AIDS. - London : Gower Academic Journals. - 0269-9370 .- 1473-5571. ; 22:10, s. 1195-1202
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Objectives: To assess the changes in HIV prevalence and incidence between 1996 and 2006 in urban areas of Bissau.Design: A cross-sectional survey of 384 randomly selected houses within a community-based follow-up study of HIV-1 and HIV-2.Methods: A total of 3242 individuals aged at least 15 years were eligible for inclusion. Participants were interviewed about behavioral and socio-economic factors and had a blood sample drawn. A total of 2548 individuals were tested for antibodies to HIV-1 and HIV-2, of whom 649 had taken part in a similar survey in 1996.Results: With 0.5% HIV dual reactions included, the overall HIV-1 prevalence was 4.6% (118 out of 2548) and the HIV-2 prevalence was 4.4% (112 out of 2548). The prevalence of HIV-1 increased more for women than men especially in the 25-34-year age group. HIV-2 prevalence decreased below 45 years of age but not for individuals more than 45 years old. The incidence rate between 1996 and 2006 was 0.5 per 100 person-years for HIV-1 and 0.24 per 100 person-years for HIV-2. Compared with a previous period from 1987 to 1996, the incidence of HIV-2 is declining whereas no significant increase in the incidence of HIV-1 was observed.Conclusions: The present study shows an increasing prevalence of HIV-1 and a decreasing prevalence of HIV-2 in Guinea-Bissau. HIV is generally a bigger problem for women. Despite the general decline in prevalence, HIV-2 may continue as an infection in older people, especially women.
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| 6. |
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| 7. |
- 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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| 8. |
- Esbjörnsson, Joakim, et al.
(författare)
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HIV-2 as a model to identify a functional HIV cure
- 2019
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Ingår i: AIDS Research and Therapy. - : Springer Science and Business Media LLC. - 1742-6405. ; 16:1
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Forskningsöversikt (refereegranskat)abstract
- Two HIV virus types exist: HIV-1 is pandemic and aggressive, whereas HIV-2 is confined mainly to West Africa and less pathogenic. Despite the fact that it has been almost 40 years since the discovery of AIDS, there is still no cure or vaccine against HIV. Consequently, the concepts of functional vaccines and cures that aim to limit HIV disease progression and spread by persistent control of viral replication without life-long treatment have been suggested as more feasible options to control the HIV pandemic. To identify virus-host mechanisms that could be targeted for functional cure development, researchers have focused on a small fraction of HIV-1 infected individuals that control their infection spontaneously, so-called elite controllers. However, these efforts have not been able to unravel the key mechanisms of the infection control. This is partly due to lack in statistical power since only 0.15% of HIV-1 infected individuals are natural elite controllers. The proportion of long-Term viral control is larger in HIV-2 infection compared with HIV-1 infection. We therefore present the idea of using HIV-2 as a model for finding a functional cure against HIV. Understanding the key differences between HIV-1 and HIV-2 infections, and the cross-reactive effects in HIV-1/HIV-2 dual-infection could provide novel insights in developing functional HIV cures and vaccines.
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| 9. |
- Esbjörnsson, Joakim, et al.
(författare)
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Increased survival among HIV-1 and HIV-2 dual-infected individuals compared to HIV-1 single-infected individuals
- 2014
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Ingår i: AIDS. - 1473-5571. ; 28:7, s. 949-957
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To compare survival times of HIV-1 single and HIV-1 and HIV-2 dual-infected individuals. Design: Prospective open cohort study. Methods: We analysed data from 259 HIV-1-seroincident cases (either HIV-1 single or HIV-1 and HIV-2 dual-infected) from a cohort with long follow-up (similar to 20 years) in order to study the influence of type of infection and infection order on mortality. Sex and age at HIV-1 infection date was controlled for in a Cox proportional-hazards model. Results: Dual-infected individuals had a 42% longer time from HIV-1 infection to death compared with single-infected individuals, adjusting for age asymmetries between groups. Dual-infected individuals with an HIV-2 infection preceding the HIV-1 infection had a more than two-fold lower mortality risk during follow-up than HIV-1 single-infected individuals. Conclusion: Survival time is longer and the risk of progression to death is lower among HIV-1 and HIV-2 dual-infected individuals compared to HIV-1 single-infected individuals. This natural inhibition could have implications for the development of future HIV-1 vaccines and therapeutics.
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| 10. |
- Esbjörnsson, Joakim, et al.
(författare)
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Inhibition of HIV-1 disease progression by contemporaneous HIV-2 infection.
- 2012
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Ingår i: New England Journal of Medicine. - 0028-4793 .- 1533-4406. ; 367:3, s. 224-232
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Progressive immune dysfunction and the acquired immunodeficiency syndrome (AIDS) develop in most persons with untreated infection with human immunodeficiency virus type 1 (HIV-1) but in only approximately 20 to 30% of persons infected with HIV type 2 (HIV-2); among persons infected with both types, the natural history of disease progression is poorly understood. METHODS: We analyzed data from 223 participants who were infected with HIV-1 after enrollment (with either HIV-1 infection alone or HIV-1 and HIV-2 infection) in a cohort with a long follow-up duration (approximately 20 years), according to whether HIV-2 infection occurred first, the time to the development of AIDS (time to AIDS), CD4+ and CD8+ T-cell counts, and measures of viral evolution. RESULTS: The median time to AIDS was 104 months (95% confidence interval [CI], 75 to 133) in participants with dual infection and 68 months (95% CI, 60 to 76) in participants infected with HIV-1 only (P=0.003). CD4+ T-cell levels were higher and CD8+ T-cell levels increased at a lower rate among participants with dual infection, reflecting slower disease progression. Participants with dual infection with HIV-2 infection preceding HIV-1 infection had the longest time to AIDS and highest levels of CD4+ T-cell counts. HIV-1 genetic diversity was significantly lower in participants with dual infections than in those with HIV-1 infection alone at similar time points after infection. CONCLUSIONS: Our results suggest that HIV-1 disease progression is inhibited by concomitant HIV-2 infection and that dual infection is associated with slower disease progression. The slower rate of disease progression was most evident in participants with dual infection in whom HIV-2 infection preceded HIV-1 infection. These findings could have implications for the development of HIV-1 vaccines and therapeutics. (Funded by the Swedish International Development Cooperation Agency-Swedish Agency for Research Cooperation with Developing Countries and others.).
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