scholarly journals The Role of Phylogenetics in Discerning HIV-1 Mixing among Vulnerable Populations and Geographic Regions in Sub-Saharan Africa: A Systematic Review

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1174
Author(s):  
George M. Nduva ◽  
Jamirah Nazziwa ◽  
Amin S. Hassan ◽  
Eduard J. Sanders ◽  
Joakim Esbjörnsson

To reduce global HIV-1 incidence, there is a need to understand and disentangle HIV-1 transmission dynamics and to determine the geographic areas and populations that act as hubs or drivers of HIV-1 spread. In Sub-Saharan Africa (sSA), the region with the highest HIV-1 burden, information about such transmission dynamics is sparse. Phylogenetic inference is a powerful method for the study of HIV-1 transmission networks and source attribution. In this review, we assessed available phylogenetic data on mixing between HIV-1 hotspots (geographic areas and populations with high HIV-1 incidence and prevalence) and areas or populations with lower HIV-1 burden in sSA. We searched PubMed and identified and reviewed 64 studies on HIV-1 transmission dynamics within and between risk groups and geographic locations in sSA (published 1995–2021). We describe HIV-1 transmission from both a geographic and a risk group perspective in sSA. Finally, we discuss the challenges facing phylogenetic inference in mixed epidemics in sSA and offer our perspectives and potential solutions to the identified challenges.

2020 ◽  
Author(s):  
Babatunde A. Olusola ◽  
David O. Olaleye ◽  
Georgina N. Odaibo

AbstractAbout 37.9 million persons are infected with HIV globally resulting in 770,000 deaths. Over 50% of this infection and deaths occur in Sub-Saharan Africa with countries like Nigeria greatly affected. The country also has one of the highest rate of new infections globally. Diverse HIV-1 subtypes have been identified in the country. Febrile persons and blood donors pose a great transmission risk in the country especially during the early stages of infection. HIV-1 rapid kits are routinely used for diagnosis among the general population and high risk groups. However, there is limited information on the usefulness of HIV rapid kits for early detection especially in areas where diverse HIV-1 subtypes circulate. In this study, the prevalence of early HIV-1 infection as well as circulating HIV-1 subtypes among febrile persons and blood donors were determined. Furthermore, the sensitivity of a widely used HIV-1 rapid antibody kit was compared with those of Antigen/Antibody ELISA based methods. Participants were recruited from selected hospitals in Ibadan and Saki, Nigeria. The prevalence of early HIV infection among 1028 febrile persons (Ibadan: 2.22%; Saki: 1.36%) and blood donors (5.07%) studied were significantly different (P<0.03674). CRF02_AG was the predominant subtype detected with more diverse HIV-1 subtypes observed among febrile persons compared to blood donors. About 1.2% of the samples detected on Antibody based ELISA methods were undetectable on the HIV-1 rapid antibody kit. Genetic diversity of HIV-1 strains among infected individuals in Oyo State, Nigeria is still relatively high. This diversity is likely impacting on diagnosis.


1992 ◽  
Vol 336 (1277) ◽  
pp. 135-155 ◽  

A mathematical model of the transmission of H IV -1 within heterosexual populations in Sub-Saharan Africa is described and its properties analysed. The model incorporates epidemiological and demographic processes and extends previous work in this area via the inclusion of age and sex dependency in rates of sexual partner change, and sexual partner choice dependent on age. Parameter assignments are made on the basis of current data on the transmission dynamics of HIV-1 and the demography of hum an populations in Africa. Both age-dependent rates of sexual activity and the sexual contact of males with females younger than themselves act to enhance the predicted demographic impact. With realistic parameter values, the model suggests AIDS is able to reverse the sign of population growth rates from positive to negative values over a timescale of a few decades. The sensitivity of this prediction is examined in relation to changes in the pattern of sexual contact between different age classes of females and males, different patterns of change in the age-dependent rate of sexual partner change, different assumptions concerning the doubling time of the epidemic in its early stages, and the relative efficiencies of viral transmission between men and women, and vice versa. The impact AIDS is predicted to have on the number of young and elderly persons as a fraction of the number of productive adults (the dependancy ratio) is examined under various assumptions concerning the weighting to be applied to mirror the burden imposed by the care of those with AIDS. The paper includes an assessment of the influence of the timing of changes in sexual behaviour, or the promotion of the use of condoms, on the predicted course of the epidemic. The paper concludes with a discussion of data needs and the model refinements required to more accurately mirror current understanding of the epidemiology of HIV -1.


2017 ◽  
Author(s):  
Chirag J. Patel ◽  
Jay Bhattacharya ◽  
John P.A. Ioannidis ◽  
Eran Bendavid

AbstractBackgroundHIV-1 remains the leading cause of death among adults in Sub-Saharan Africa, and over 1 million people are infected annually. Better identification of at-risk groups could benefit prevention and treatment programmes. We systematically identified factors related to HIV-1 infection in two nationally representative cohorts of women that participated in Zambia’s Demographic and Health Surveys (DHS).MethodsWe conducted a comprehensive analysis to identify and replicate the association of 1,415 social, economic, environmental, and behavioral indicators with HIV-1 status. We used the 2007 and 2013-2014 DHS surveys conducted among 5,715 and 15,433 Zambian women, respectively (727 indicators in 2007; 688 in 2013-2014; 688 in both). We used false discovery rate criteria to identify indicators that are strongly associated with HIV-1 in univariate and multivariate models in the entire population, as well as in subgroups stratified by wealth, residence, age, and history of HIV-1 testing.FindingsIn the univariate analysis we identified 102 and 182 variables that are associated with HIV-1 in the 2007 and 2013-2014 surveys, respectively, among which 79 were associated in both. Variables that were associated with HIV-1 status in all full-sample models (unadjusted and adjusted) as well as in at least 17 out of 18 subgroups include being formerly in a union (adjusted OR 2007 2.8, p<10−16; 2013-2014 2.8, p<10−29), widowhood (adjusted OR 2007 3.7, p<10−12; 2013-2014 4.2, p<10−30), history of genital ulcers in the last 12 months (adjusted 2007 OR 2.4, p<10−5; 2013-2014 2.2, p<10−6), and having a woman for the head of the household (2007 OR 1.7, p<10−7; 2013-2014 OR 2.1, p<10−26), while owning a bicycle (adjusted 2007 OR 0.6, p<10−6; 2013-2014 0.6, p<10−8) and currently breastfeeding (adjusted 2007 OR 0.5, p<10−9; 2013-2014 0.4, p<10−26) were associated with decreased risk. Using the identified variables, area under the curve for HIV-1 positivity ranged from 0.76 to 0.82.InterpretationOur X-wide association study in Zambian women identifies multiple under-recognized factors correlated with HIV-1 infection in 2007 and 2013-2014, including widowhood, breastfeeding, and being the head of the household. These variables could be used to improve HIV-1 testing and identification programs.


Author(s):  
Peter Kayode Oniemola ◽  
Jane Ezirigwe

To achieve universal energy access will attract huge capital investments. If sub-Saharan Africa is to realize anything close to the ambitious goals set for its energy access, then new actors, innovative funding mechanisms and sustainable technologies will have to be attracted. Finance is needed for activities such as rural electrification, clean cooking facilities, diesel motors and generators, other renewable energy technologies, oil and gas infrastructures, etc. Finance is also needed in research and development of suitable technologies and funding options as well as investment in the capacity to formulate and implement sound energy policies. This chapter examines the varied financing options for energy access in sub-Saharan Africa. It argues that with appropriate laws in place and effective mechanism for implementation, African countries can significantly engage private sector financing, international financial institutions and foreign donors. The role of the law here will be in creating an enabling environment for financing.


In the chapter, Haq gives a snapshot of the human progress of South Asia, comparing it with other regions. He was worried about the region beginning to lag behind all other regions, including Sub-Saharan Africa. He highlights the role of the two largest economies in the region, India and Pakistan, in financing the major investment in education, health and nutrition for the people. Haq advocates some fiscal and monetary reforms are suggested to invest in human development.


2021 ◽  
Vol 22 (9) ◽  
pp. 5052
Author(s):  
Yue Zheng ◽  
Xian-Wen Yang ◽  
Dominique Schols ◽  
Mattia Mori ◽  
Bruno Botta ◽  
...  

Cassia abbreviata is widely used in Sub-Saharan Africa for treating many diseases, including HIV-1 infection. We have recently described the chemical structures of 28 compounds isolated from an alcoholic crude extract of barks and roots ofC. abbreviata, and showed that six bioactive compounds inhibit HIV-1 infection. In the present study, we demonstrate that the six compounds block HIV-1 entry into cells: oleanolic acid, palmitic acid, taxifolin, piceatannol, guibourtinidol-(4α®8)-epiafzelechin, and a novel compound named as cassiabrevone. We report, for the first time, that guibourtinidol-(4α®8)-epiafzelechin and cassiabrevone inhibit HIV-1 entry (IC50 of 42.47 µM and 30.96 µM, respectively), as well as that piceatannol interacts with cellular membranes. Piceatannol inhibits HIV-1 infection in a dual-chamber assay mimicking the female genital tract, as well as HSV infection, emphasizing its potential as a microbicide. Structure-activity relationships (SAR) showed that pharmacophoric groups of piceatannol are strictly required to inhibit HIV-1 entry. By a ligand-based in silico study, we speculated that piceatannol and norartocarpetin may have a very similar mechanism of action and efficacy because of the highly comparable pharmacophoric and 3D space, while guibourtinidol-(4α®8)-epiafzelechin and cassiabrevone may display a different mechanism. We finally show that cassiabrevone plays a major role of the crude extract of CA by blocking the binding activity of HIV-1 gp120 and CD4.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nancy S. Matowo ◽  
Jackline Martin ◽  
Manisha A. Kulkarni ◽  
Jacklin F. Mosha ◽  
Eliud Lukole ◽  
...  

AbstractAnopheles funestus is playing an increasing role in malaria transmission in parts of sub-Saharan Africa, where An. gambiae s.s. has been effectively controlled by long-lasting insecticidal nets. We investigated vector population bionomics, insecticide resistance and malaria transmission dynamics in 86 study clusters in North-West Tanzania. An. funestus s.l. represented 94.5% (4740/5016) of all vectors and was responsible for the majority of malaria transmission (96.5%), with a sporozoite rate of 3.4% and average monthly entomological inoculation rate (EIR) of 4.57 per house. Micro-geographical heterogeneity in species composition, abundance and transmission was observed across the study district in relation to key ecological differences between northern and southern clusters, with significantly higher densities, proportions and EIR of An. funestus s.l. collected from the South. An. gambiae s.l. (5.5%) density, principally An. arabiensis (81.1%) and An. gambiae s.s. (18.9%), was much lower and closely correlated with seasonal rainfall. Both An. funestus s.l. and An. gambiae s.l. were similarly resistant to alpha-cypermethrin and permethrin. Overexpression of CYP9K1, CYP6P3, CYP6P4 and CYP6M2 and high L1014S-kdr mutation frequency were detected in An. gambiae s.s. populations. Study findings highlight the urgent need for novel vector control tools to tackle persistent malaria transmission in the Lake Region of Tanzania.


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