Despite the importance of youth sexual behaviour for sexual and reproductive health and the severity of the HIV/AIDS there is relatively little empirical research on factors affecting the age at sexual debut in South Africa. In my dissertation I used survival analysis techniques to identify significant predictors of early sexual debut in a South African context. The results may assist in devising strategies and action plans to be used to educate adolescents in making informed and safe decisions regarding sexual debut.
We conducted surveys of travellers and their movement patterns in Mali, Burkina Faso, Zambia and Tanzania. We found that women travelling with children are a consistent group of relevance to malaria transmission. Our study also highlighted youth workers as a key traveller group of relevance to parasite dispersal in Mali.
The objective of my thesis was to develop a novel, parameterised mechanistic mathematical model which describes the dynamics of parasite invasion during the initial stages of malarial infection.
Common indicators such as the number of new sexual partners in a given year and the lifetime number of sexual partners are used in several analyses to predict the risk of contracting HIV. However, are these indicators consistent?
Intimate partner violence (IPV) is a public health problem that has drawn considerable research attention over the last few decades. Studies that have looked at age disparity as a risk factor of IPV show conflicting results regarding the direction of the association. It is due to these conflicting results that we sought to investigate if having an older partner is protective against IPV, compared to having a partner of closer age, in Sub-Saharan Africa using data from Demographic Health Surveys.
In the last week of June 2016, fifteen scientists converged on Stellenbosch for a week-long intensive workshop, hosted by SACEMA, aimed at sharing their knowledge of the problems and prospects associated with modelling the population dynamics of tsetse flies (Glossina spp) and the trypanosomes that they transmit in Africa to game animals, domestic livestock and humans.
The annual ‘Research Days’ meeting in Stellenbosch, to which all SACEMA funded students and their supervisors are invited, was this year extended to a four day training and research event and took place from 11 to 14 April 2016.
Botswana has made substantial progress towards meeting the UNAIDS 90-90-90 target by 2020 under which 90% of people living with HIV will know their status, 90% of these will be on anti-retroviral therapy (ART), and 90% of these will have viral loads below 400/µL. In this paper we use a previously published model for Botswana to assess the future impact of their HIV control programme on new HIV infections, AIDS related mortality and the costs of doing this. We show that while treatment will have a major impact on incidence and mortality and will lead to net cost savings, prevention will lead to further small reductions in incidence and mortality, but will entail significant cost increases.
A new formal ‘R Package’ to support incidence estimation is available on the Comprehensive R Archive Network (CRAN). This is the canonical way that the R community distributes stable packages to share functionality, and it is the heart and soul of the R coding environment. The new release through CRAN will make a substantial range of functionalities around incidence survey design and survey data analysis seamlessly and flexibly available to any skilled R programmer/analyst.
It is believed that most tumours are heterogeneous and many cancers contain small populations of highly tumorigenic and intrinsically drug resistant cancer stem cells (CSCs). Gaining deeper insights into the development of stem cells in general and CSCs in particular with the aim of interfering with the emerging CSC population for the purpose of bringing about its eradication poses challenges to biomedical research and engenders approaches from various viewpoints including by mathematical modelling. We used an ordinary differential equation formulation to study a nonlinear model that was based on normal and abnormal cells, including CSC, behaviour in the bone marrow and peripheral blood.