Analysing the impact of migration on HIV/AIDS cases using epidemiological modelling to guide policy makers

Understanding HIV/AIDS dynamics: insights from CD4+T cells, antiretroviral treatment, and country-specific analysis

In this article, we present a mathematical model for human immunodeficiency virus (HIV)/Acquired immune deficiency syndrome (AIDS), taking into account the number of CD4+T cells and antiretroviral treatment. This model is developed based on the susceptible, infected, treated, AIDS (SITA) framework, wherein the infected and treated compartments are divided based on the number of CD4+T cells. Additionally, we consider the possibility of treatment failure, which can exacerbate the condition of the treated individual. Initially, we analyze a simplified HIV/AIDS model without differentiation between the infected and treated classes. Our findings reveal that the global stability of the HIV/AIDS-free equilibrium point is contingent upon the basic reproduction number being less than one. Furthermore, a bifurcation analysis demonstrates that our simplified model consistently exhibits a transcritical bifurcation at a reproduction number equal to one. In the complete model, we elucidate how the control reproduction number determines the stability of the HIV/AIDS-free equilibrium point. To align our model with the empirical data, we estimate its parameters using prevalence data from the top four countries affected by HIV/AIDS, namely, Eswatini, Lesotho, Botswana, and South Africa. We employ numerical simulations and conduct elasticity and sensitivity analyses to examine how our model parameters influence the control reproduction number and the dynamics of each model compartment. Our findings reveal that each country displays distinct sensitivities to the model parameters, implying the need for tailored strategies depending on the target country. Autonomous simulations highlight the potential of case detection and condom use in reducing HIV/AIDS prevalence. Furthermore, we identify that the quality of condoms plays a crucial role: with higher quality condoms, a smaller proportion of infected individuals need to use them for the potential eradication of HIV/AIDS from the population. In our optimal control simulations, we assess population behavior when control interventions are treated as time-dependent variables. Our analysis demonstrates that a combination of condom use and case detection, as time-dependent variables, can significantly curtail the spread of HIV while maintaining an optimal cost of intervention. Moreover, our cost-effectiveness analysis indicates that the condom use intervention alone emerges as the most cost-effective strategy, followed by a combination of case detection and condom use, and finally, case detection as a standalone strategy.

An ALP enzyme-based electrochemical biosensor coated with signal-amplifying BaTiO3 nanoparticles for the detection of an antiviral drug in human blood serum

Tenofovir (TFV) is an antiviral drug used to treat the co-infections of HIV/HBV viruses. Accurate monitoring of TFV drug levels is essential for evaluating patient adherence, optimizing dosage, and assessing treatment efficacy. Herein, we propose an innovative electrochemical sensing approach by using the alkaline phosphatase (ALP) enzyme with the support of BaTiO3 nanoparticles. An attractive sensitivity and selectivity of the developed sensor towards TFV detection were achieved. First, the nanoparticles were synthesized by following a single-step sol-gel method and characterized through various analytical techniques, including SEM, EDX, FT-IR, BET, zeta potential, XRD, and UV-vis and Raman spectroscopy. The suggested mechanism demonstrated the formation of a strong bond between TFV and the ALP enzyme, primarily through the phosphate group, resulting in enzyme inhibition. Various parameters like nanoparticle amount, electrode modification time with enzyme and BaTiO3 nanoparticles, and drug incubation time were optimized. The biosensor demonstrated an outstanding limit of detection (LOD) of 0.09 nM and recovery percentages of 98.6-106% in human blood serum, indicating adequate repeatability and selectivity. The proposed biosensor can be converted into a portable device for measuring small sample volumes and observing patients for immediate medical care or personalized therapies. It achieved better sensitivity compared to existing methods, making it suitable for precise drug detection in microdoses.

"It was protected, except, it wasn't [with] a condom": a mixed-methods study of BBVs/STIs protective practices among International University Students in Sydney, Australia

BACKGROUND

A number of previous sex-related studies among international students in Australia and other Western societies may be limited by conflating students from conservative and non-conservative sexual backgrounds. Such conflation leads to situations where nuances and complexities around sex-related experiences are lost or, at most, tangentially investigated. To address this research problem, this study used a mixed-methods design to examine protective practices against blood-borne viruses and sexually transmissible infections (BBVs/STIs) among Sydney-based East Asian and sub-Saharan African international students.

METHODS

This mixed-methods study generated quantitative data using anonymous online survey (n = 149), and qualitative data through in-depth interviews (n = 20). The main recruitment strategy involved advertising the study through paper and electronic flyers. Quantitative data were analysed using logistic regression, while interviews data were analysed using reflexive thematic analysis.

RESULTS

Self-reported BBVs/STIs protective practices in the last 12 months include abstinence (28.7%), consistent condom use (19.9%), occasional condom use (18.7%), single partner fidelity (25.1%), other strategies (1.8%), and nothing (5.8%). Further, findings from the bivariate analysis showed higher BBVs/STIs prevention knowledge, lower acculturation into Australian sexual culture, greater access to sexual health information, less conservative sexual norms, greater emotional social support and older age were significantly associated with increased protective practices. Variables significant at bivariate level were entered into a logistic regression. The model was statistically significant, (X²(6) = 31.33, p < 0.01) and explained 33.1% of the variance in BBVs/STIs protective practices. However, only acculturation to sexual norms in Australia (OR = 0.883, 95% CI = 0.820-0.952) was found to be independent predictor of BBVs/STIs protective practices. The results of the study based on the quantitative data, indicated condom use (consistent and occasional) was the most reported BBVs/STIs protective behaviour among sexually active participants. Therefore, interviews data was used to explore condom-use motives and practices. The interviews results showed participants primary concern as regards condom use was around pregnancy and not BBVs/STIs. Thus, some participants described safe sex largely as contraception, with BBVs/STIs constituting a secondary concern or no concern at all.

CONCLUSIONS

Based on the results of this study, tailored sexual health interventions for international students; which incorporate strategies for modifying perceived sexual norms in Australia, are advocated. In addition, this study recommends sexual health interventions that promote dual protection of condoms for both contraception and BBVs/STIs.

Are Unequal Policies in Pre-Exposure Prophylaxis Uptake Needed to Improve Equality? An Examination Among Men Who Have Sex with Men in Los Angeles County

Racial and ethnic minority men who have sex with men (MSM) are disproportionately affected by HIV/AIDS in Los Angeles County (LAC), an important epicenter in the battle to end HIV. We examine tradeoffs between effectiveness and equality of pre-exposure prophylaxis (PrEP) allocation strategies among different racial and ethnic groups of MSM in LAC and provide a framework for quantitatively evaluating disparities in HIV outcomes. To do this, we developed a microsimulation model of HIV among MSM in LAC using county epidemic surveillance and survey data to capture demographic trends and subgroup-specific partnership patterns, disease progression, patterns of PrEP use, and patterns for viral suppression. We limit analysis to MSM, who bear most of the burden of HIV/AIDS in LAC. We simulated interventions where 3000, 6000, or 9000 PrEP prescriptions are provided annually in addition to current levels, following different allocation scenarios to each racial/ethnic group (Black, Hispanic, or White). We estimated cumulative infections averted and measures of equality, after 15 years (2021-2035), relative to base case (no intervention). By comparing allocation strategies on the health equality impact plane, we find that, of the policies evaluated, targeting PrEP preferentially to Black individuals would result in the largest reductions in incidence and disparities across the equality measures we considered. This result was consistent over a range of PrEP coverage levels, demonstrating that there are "win-win" PrEP allocation strategies that do not require a tradeoff between equality and efficiency.