scholarly journals Impact of Endemic Infections on HIV Susceptibility in Sub-Saharan Africa

Author(s):  
Sergey Yegorov ◽  
Vineet Joag ◽  
Ronald M. Galiwango ◽  
Sara V. Good ◽  
Brenda Okech ◽  
...  

AbstractHuman immunodeficiency virus (HIV) remains a leading cause of global morbidity with the highest burden in Sub-Saharan Africa (SSA). For reasons that are incompletely understood, the likelihood of HIV transmission is several fold higher in SSA than in higher income countries, and most of these infections are acquired by young women. Residents of SSA are also exposed to a variety of endemic infections, such as malaria and various helminthiases that could influence mucosal and systemic immunology. Since these immune parameters are important determinants of HIV acquisition and progression, this review explores the possible effects of endemic infections on HIV susceptibility and summarizes current knowledge of the epidemiology and underlying immunological mechanisms by which endemic infections could impact HIV acquisition. A better understanding of the interaction between endemic infections and HIV may enhance HIV prevention programs in SSA.

Sexual Health ◽  
2014 ◽  
Vol 11 (2) ◽  
pp. 126 ◽  
Author(s):  
Ying-Ru Lo ◽  
Masaya Kato ◽  
Nittaya Phanuphak ◽  
Masami Fujita ◽  
Duong Bui Duc ◽  
...  

Evidence has emerged over the past few years on the effectiveness of antiretroviral-based prevention technologies to prevent (i) HIV transmission while decreasing morbidity and mortality in HIV-infected persons, and (ii) HIV acquisition in HIV-uninfected individuals through pre-exposure prophylaxis (PrEP). Only few of the planned studies on treatment as prevention (TasP) are conducted in Asia. TasP might be more feasible and effective in concentrated rather than in generalised epidemics, as resources for HIV testing and antiretroviral treatment could focus on confined and much smaller populations than in the generalised epidemics observed in sub-Saharan Africa. Several countries such as Cambodia, China, Thailand and Vietnam, are now paving the way to success. Similar challenges arise for both TasP and PrEP. However, the operational issues for PrEP are amplified by the need for frequent retesting and ensuring adherence. This paper describes challenges for the implementation of antiretroviral-based prevention and makes the case that TasP and PrEP implementation research in Asia is much needed to provide insights into the feasibility of these interventions in populations where firm evidence of ‘real world’ effectiveness is still lacking.


Author(s):  
Ceri Evans ◽  
Bernard Chasekwa ◽  
Robert Ntozini ◽  
Florence D Majo ◽  
Kuda Mutasa ◽  
...  

Abstract Background Clinical outcomes of children who are human immunodeficiency virus (HIV)–exposed in sub-Saharan Africa remain uncertain. Methods The Sanitation Hygiene Infant Nutrition Efficacy (SHINE) trial evaluated improved infant and young child feeding (IYCF) and/or improved water, sanitation, and hygiene in 2 rural Zimbabwean districts with 15% antenatal HIV prevalence and > 80% prevention of mother-to-child transmission (PMTCT) coverage. Children born between February 2013 and December 2015 had longitudinal HIV testing and anthropometry. We compared mortality and growth between children who were HIV-exposed and HIV-unexposed through 18 months. Children receiving IYCF were excluded from growth analyses. Results Fifty-one of 738 (7%) children who were HIV-exposed and 198 of 3989 (5%) children who were HIV-unexposed (CHU) died (hazard ratio, 1.41 [95% confidence interval {CI}, 1.02–1.93]). Twenty-five (3%) children who were HIV-exposed tested HIV positive, 596 (81%) were HIV-exposed uninfected (CHEU), and 117 (16%) had unknown HIV status by 18 months; overall transmission estimates were 4.3%–7.7%. Mean length-for-age z score at 18 months was 0.38 (95% CI, .24–.51) standard deviations lower among CHEU compared to CHU. Among 367 children exposed to HIV in non-IYCF arms, 147 (40%) were alive, HIV-free, and nonstunted at 18 months, compared to 1169 of 1956 (60%) CHU (absolute difference, 20% [95% CI, 15%–26%]). Conclusions In rural Zimbabwe, mortality remains 40% higher among children exposed to HIV, vertical transmission exceeds elimination targets, and half of CHEU are stunted. We propose the composite outcome of “alive, HIV free, and thriving” as the long-term goal of PMTCT programs. Clinical Trials Registration NCT01824940.


2018 ◽  
Vol 92 (14) ◽  
Author(s):  
Hanna B. Scinto ◽  
Sandeep Gupta ◽  
Swati Thorat ◽  
Muhammad M. Mukhtar ◽  
Anthony Griffiths ◽  
...  

ABSTRACTThe phase III RV144 human immunodeficiency virus (HIV) vaccine trial conducted in Thailand remains the only study to show efficacy in decreasing the HIV acquisition risk. In Thailand, circulating recombinant forms of HIV clade A/E (CRF01_AE) predominate; in such viruses,envoriginates from clade E (HIV-E). We constructed a simian-human immunodeficiency virus (SHIV) chimera carryingenvisolated from an RV144 placebo recipient in the SHIV-1157ipd3N4 backbone. The latter contains long terminal repeats (LTRs) with duplicated NF-κB sites, thus resembling HIV LTRs. We devised a novel strategy to adapt the parental infectious molecular clone (IMC), R5 SHIV-E1, to rhesus macaques: the simultaneous depletion of B and CD8+cells followed by the intramuscular inoculation of proviral DNA and repeated administrations of cell-free virus. High-level viremia and CD4+T-cell depletion ensued. Passage 3 virus unexpectedly caused acute, irreversible CD4+T-cell loss; the partially adapted SHIV had become dual tropic. Virus and IMCs with exclusive R5 tropism were reisolated from earlier passages, combined, and used to complete adaptation through additional macaques. The final isolate, SHIV-E1p5, remained solely R5 tropic. It had a tier 2 neutralization phenotype, was mucosally transmissible, and was pathogenic. Deep sequencing revealed 99% Env amino acid sequence conservation; X4-only and dual-tropic strains had evolved independently from an early branch of parental SHIV-E1. To conclude, our primate model data reveal that SHIV-E1p5 recapitulates important aspects of HIV transmission and pathobiology in humans.IMPORTANCEUnderstanding the protective principles that lead to a safe, effective vaccine against HIV in nonhuman primate (NHP) models requires test viruses that allow the evaluation of anti-HIV envelope responses. Reduced HIV acquisition risk in RV144 has been linked to nonneutralizing IgG antibodies with a range of effector activities. Definitive experiments to decipher the mechanisms of the partial protection observed in RV144 require passive-immunization studies in NHPs with a relevant test virus. We have generated such a virus by insertingenvfrom an RV144 placebo recipient into a SHIV backbone with HIV-like LTRs. The final SHIV-E1p5 isolate, grown in rhesus monkey peripheral blood mononuclear cells, was mucosally transmissible and pathogenic. Earlier SHIV-E passages showed a coreceptor switch, again mimicking HIV biology in humans. Thus, our series of SHIV-E strains mirrors HIV transmission and disease progression in humans. SHIV-E1p5 represents a biologically relevant tool to assess prevention strategies.


2020 ◽  
Author(s):  
Catherine Stein ◽  
Penelope Bencheck ◽  
Jacquelaine Bartlett ◽  
Robert P Igo ◽  
Rafal S Sobota ◽  
...  

Background: Tuberculosis (TB) is the most deadly infectious disease globally and highly prevalent in the developing world, especially sub-Saharan Africa. Even though a third of humans are exposed to Myocbacterium tuberculosis (Mtb), most infected immunocompetent individuals do not develop active TB. In contrast, for individuals infected with both TB and the human immunodeficiency virus (HIV), the risk of active disease is 10% or more per year. Previously, we identified in a genome-wide association study a region on chromosome 5 that was associated with resistance to TB. This region included epigenetic marks that could influence gene regulation so we hypothesized that HIV-infected individuals exposed to Mtb, who remain disease free, carry epigenetic changes that strongly protect them from active TB. To test this hypothesis, we conducted a methylome-wide study in HIV-infected, TB-exposed cohorts from Uganda and Tanzania. Results: In 221 HIV-infected adults from Uganda and Tanzania, we identified 3 regions of interest that included markers that were differentially methylated between TB cases and LTBI controls, that also included methylation QTLs and associated SNPs: chromosome 1 (RNF220, p=4x10-5), chromosome 2 (between COPS8 and COL6A3 genes, p=2.7x10-5), and chromosome 5 (CEP72, p=1.3x10-5). These methylation results colocalized with associated SNPs, methylation QTLs, and methylation x SNP interaction effects. These markers were in regions with regulatory markers for cells involved in TB immunity and/or lung. Conclusion: Epigenetic regulation is a potential biologic factor underlying resistance to TB in immunocompromised individuals that can act in conjunction with genetic variants.


2019 ◽  
Author(s):  
antonio montañés bernal ◽  
Cristina Martínez

Abstract Background This paper studies the evolution of the human immunodeficiency virus (HIV) prevalence and incidence rates in Sub-Saharan African countries, paying special attention to the possible presence of a unique pattern of behavior of these variables across the mentioned countries during the 1990-2016 period. Methods We employ time series methods designed to analyze the hypothesis of convergence. We apply these tests to prevalence and incidence rates of the Sub-Saharan African countries for the 1990-2016 period. Results We cannot reject the null hypothesis of convergence for male prevalence rates and total incidence rates. By contrast, we can observe divergence in female prevalence rates, Conclusion The evolution of the male prevalence rates and incidence rates is quite similar for the Sub-Saharan countries. But, we can still find different patterns of behavior for female prevalence rates. Therefore, the recent HIV-oriented policies have not been able to control its transmission yet. We can also appreciate that some socioeconomic variables play a crucial role to explain the different behaviors of female prevalence rates, especially the level of female education. So, focusing on this variable is crucial to control this pandemia.


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