Latest News Archive

Please select Category, Year, and then Month to display items
Previous Archive
11 December 2019 | Story Leonie Bolleurs
Aids read more

According to Global Statistics, there were approximately 37,9 million people across the globe with HIV/Aids in 2018. They also state that in 2018, an estimated 1,7 million individuals worldwide became newly infected with HIV. 

In the city of Masvingo, Zimbabwe, Claris Shoko is a Statistics lecturer at the Great Zimbabwe University. In her PhD thesis at the University of the Free State (UFS) in the Department of Mathematical Statistics and Actuarial Sciences, she presented the argument that the inclusion of both the CD4 cell count and the viral-load counts in the monitoring and management of HIV+ patients on antiretroviral therapy (ART), is helping in reducing mortality rates, leading to improved life expectancy for HIV/Aids patients. 

She received her doctoral degree at the December UFS Graduation Ceremonies, with her thesis: Continuous-time Markov modelling of the effects of treatment regimens on HIV/Aids immunology and virology. 

CD4 cell count and viral-load count

Dr Shoko explains: “When the human immunodeficiency virus (HIV) enters the human body, the virus attacks the CD4 cells in their blood. This process damages CD4 cells, causing the number of white blood cells in the body to drop, making it difficult to fight infections.”

“Clinical markers such as CD4 cell count and viral-load count (number of HIV particles in a ml of blood) provide information about the progression of HIV/Aids in infected individuals. These markers fully define the immunology and the virology of HIV-infected individuals, thereby giving us a clear picture of how HIV/Aids evolve within an individual.”

Dr Shoko continues: “The development of highly active antiretroviral therapy (HAART) has helped substantially to reduce the death rate from HIV. HAART reduces viral load-count levels, blocking replication of HIV particles in the blood, resulting in an increase of CD4 cell counts and the life expectancy of individuals infected with HIV. This has made CD4 cell counts and viral-load counts the fundamental laboratory markers that are regularly used for patient management, in addition to predicting HIV/Aids disease progression or treatment outcomes.”

In the treatment of HIV/Aids, medical practitioners prescribe combination therapy to attack the virus at different stages of its life cycle, and medication to treat the opportunistic infections that may occur. “The introduction of combined antiretroviral therapy (cART) has led to the dramatic reduction in morbidity and mortality at both individual level and population level,” states Dr Shoko.

Once HIV-positive patients are put on cART, the effectiveness of treatment is monitored after the first three months and a further follow-up is done every six months thereafter. During the monitoring stages, CD4 cell count and viral load is measured. Patients are also screened for any tuberculosis (TB) co-infection and checked for any signs of drug resistance. These variables determine whether or not there is a need for treatment change. 

She continues: “Previous studies on HIV modelling could not include both CD4 cell count and viral load in one model, because of the collinearity between the two variables. In this study, the principal component approach for the treatment of collinearity between variables is used. Both variables were then included in one model, resulting in a better prediction of mortality than when only one of the variables is used.”

“Viral-load monitoring helps in checking for any possibilities of virologic failure or viral rebound, which increases the rate of mortality if not managed properly. CD4 cell count then comes in to monitor the potential development of opportunistic infections such as TB. TB is extremely fatal, but once detected and treated, the survival of HIV/Aids patients is assured,” Dr Shoko explains.

Markov model

She applied the Markov model in her study. The model, named after the Russian mathematician Andrey Markov, represents a general category of stochastic processes, characterised by six basic attributes: states, stages, actions, rewards, transitions, and constraints. 

According to Dr Shoko, Markov models assume that a patient is always in one of a finite number of discrete states, called Markov states. All events are modelled as transitions from one state to another. Each state is assigned a utility, and the contribution of this utility to the overall prognosis depends on the length of time spent in each state. For example, for a patient who is HIV positive, these states could be HIV+ (CD4 cell count above 200 cells/mm3), Aids (CD4 cell count below 200 cells/mm3) and Dead.

“Markov models are ideal for use in HIV/Aids studies, because they estimate the rate of transition between multiple-disease states while allowing for the possible reversibility of some states,” says Dr Shoko, quoting Hubbard and Zhou.

“Relatively fewer HIV modelling studies include a detailed description of the dynamics of HIV viral load count during stages of HIV disease progression. This could be due to the unavailability of data on viral load, particularly from low- and middle-income countries that have historically relied on monitoring CD4 cell counts for patients on ART because of higher costs of viral load-count testing,” Dr Shoko concludes

News Archive

Inaugural lecture: Prof. Annette Wilkinson
2008-04-16

A strong plea for a pursuit of “scholarship” in higher education

Prof. Annette Wilkinson of the Centre for Higher Education Studies and Development in the Faculty of the Humanities at the University of the Free State (UFS) made as strong plea for a pursuit of “scholarship” in higher education.

She said in her inaugural lecture that higher education has to deal with changes and demands that necessitate innovative approaches and creative thinking when it concerns effective teaching and learning in a challenging and demanding higher education environment. She referred to a recent research report prepared for the Council for Higher Education (CHE) which spells out the alarming situation regarding attrition rates and graduation output in South African higher education and emphasises factors leading to the situation. These factors include socio-economic conditions and shortcomings in the school and the subsequent under preparedness of a very large proportion of the current student population. However, what is regarded as one of the key factors within the sector’s control is the implementation of strategies for improving graduate output.

She said: “The CHE report expresses concern about academics’ adherence to traditional teaching practices at institutions, which have not changed significantly to make provision for the dramatic increase in diversity since the 1980s.

“Raising the profile of teaching and learning in terms of accountability, recognition and scholarship is essential for successful capacity-building,” she said. “The notion of scholarship, however, brings to the minds of many academics the burden of ‘publish or perish’. In many instances, the pressures to be research-active are draining the value put on teaching. Institutions demand that staff produce research outputs in order to qualify for any of the so-called three Rs – resources, rewards and recognition.

“These have been abundant for research, but scarce when it comes to teaching – with the status of the latter just not on the same level as that of research. From within their demanding teaching environments many lecturers just feel they do not have the time to spend on research because of heavy workloads, that their efforts are under-valued and that they have to strive on the basis of intrinsic rewards.”

She said: “It is an unfortunate situation that educational expertise, in particular on disciplinary level, is not valued, even though in most courses, as in the Programme in Higher Education Studies at the UFS, all applications, whether in assignments, projects or learning material design, are directly applied to the disciplinary context. We work in a challenging environment where the important task of preparing students for tomorrow requires advanced disciplinary together with pedagogical knowledge.”

Prof. Wilkinson argued that a pursuit of the scholarship of teaching and learning holds the potential of not only improving teaching and learning and consequently success rates of students, but also of raising the status of teaching and recognising the immense inputs of lecturers who excel in a very demanding environment. She emphasised that not all teaching staff will progress to the scholarship level or are interested in such an endeavour. She therefore suggested a model in which performance in the area of teaching and learning can be recognised, rewarded and equally valued on three distinct levels, namely the levels of excellence, expertise and scholarship. An important feature of the model is that staff in managerial, administrative and support posts can also be rewarded for their contributions on the different levels for all teaching related work.

Prof. Wilkinson also emphasised the responsibility or rather, accountability, of institutions as a whole, as well as individual staff members, in providing an environment and infrastructure where students can develop to their full potential. She said that in this environment the development of the proficiency of staff members towards the levels of excellence, expertise and scholarship must be regarded as a priority.

“If we want to improve students’ success rates the institution should not be satisfied with the involvement in professional development opportunities by a small minority, but should set it as a requirement for all teaching staff, in particular on entry into the profession and for promotion purposes. An innovative approach towards a system of continuous professional development, valued and sought after, should be considered and built into the institutional performance management system.”

As an example of what can be achieved, Prof. Wilkinson highlighted the work of one of the most successful student support programmes at the UFS, namely the Career Preparation Programme (CPP), implemented fourteen years ago, bringing opportunities to thousands of students without matric exemption. The programme is characterised by dedicated staff, a challenging resource-based approach and foundational courses addressing various forms of under preparedness. Since 1993 3 422 students gained entry into UFS degree programmes after successfully completing the CPP; since 1996 1 014 of these students obtained their degrees, 95 got their honours degrees, 18 their master’s degrees and six successfully completed their studies as medical doctors.

Prof. Wilkinson said: “I believe we have the structures and the potential to become a leading teaching-learning university and region, where excellence, expertise and scholarship are recognised, honoured and rewarded.”

 

We use cookies to make interactions with our websites and services easy and meaningful. To better understand how they are used, read more about the UFS cookie policy. By continuing to use this site you are giving us your consent to do this.

Accept