HIV/AIDS, even at the cusp of the fourth decade after its detection among humanbeings, still bedevils medical science and poses serious threats to human health. Globally,specifically in sub-Sahara Africa, the disease remains one of the major causes ofdeath. The battle to eradicate or control HIV/AIDS, which started as soon as the detectionof HIV, is far from being won, though there have been significant advances atvarious fronts. HIV/AIDS epidemic is a multifaceted problem with social, behaviouraland biological aspects, and it is generally agreed that in the absence of a cure, theburden of disease prevention and control falls significantly and predominantly on individualbehavioural change. Empirical studies have found heavy alcohol consumptionto be a fuelling factor for HIV/AIDS infection and progression. Motivated and enlightenedby these findings, Thomas and Lungu have previously constructed one-sex and two-sex  models for the influence of alcohol consumption on the spreadof HIV/AIDS with two stages for disease progression. In this chapter, a staged progression(SP) and differential infectivity (DI) mathematical model, with and withoutdifferential susceptibility (DS), is constructed with four stages for disease progression,as an extension of . Our model with differential susceptibility exhibits thephenomenon of backward bifurcation, and we find that the choice of incidence functionis not as decisive as the choice of differential susceptibility, for the phenomenonof backward bifurcation to occur. Numerical simulations explore the benefits of ongoingrecovery from heavy-drinking habits among the people living with HIV/AIDS(PLWHA) and the corresponding decline in the number of HIV population, new HIVinfections, number in need of anti-retroviral therapy (ART), etc. We conclude thatefforts to bring in behaviour change among the population will fall short of achievingtargeted goals, unless the problem of heavy alcohol consumption, among both the HIV negative and HIV positive individuals, is adequately recognized and addressedas a driver of the epidemic. Although our model can be applied in many situations,it is specially relevant to sub-Sahara Africa where heavy alcohol consumption amongyoung people is on the increase, age of onset of alcohol use is on the decrease andHIV/AIDS is highly prevalent.
|Title of host publication||A Treatise of Biological Models|
|Publisher||Nova Science Publishers, Inc.|
|Number of pages||37|
|Publication status||Published - Dec 1 2012|
All Science Journal Classification (ASJC) codes