Combatting Infections of National Priority

Source: van Schalkwyk, C et al. Scientific reports,

SACEMA contributes research, advice, and technical assistance to combat infections of national priority in South Africa. This includes mathematical modelling and epidemiological research on the impact of interventions against the spread tuberculosis, HIV/AIDS, and sexually-transmitted infections. An overview of specific projects and initiatives is provided under the respective project sections.

For more than twenty years, treatment options have been available that make it possible for most people living with HIV to control viral replication to the extent that they can live a normal, active life with few treatment side effects. For over ten years, these treatments were rationed and restricted to patients with very advanced disease, for fear of over-stretching systems, triggering side effects, and breeding drug resistance. These concerns are no longer seen as reasons to restrict antiretroviral therapy, but merely as issues to monitor and manage. Modelling the many trade-offs involved has been crucial to understanding that early treatment is not only in the best interests of HIV infected patients, but also the best currently available way to reduce their infectiousness. It is now largely understood that the only thing more likely to overwhelm the health care system than opening the doors to treatment for all, is the failure to open those doors. SACEMA was for years at the forefront of this debate. Models were used to indicate the relationships between interventions and their consequences, so that the long term benefits of more treatment could be sensibly weighed against the challenges, costs, and risks.

The long-standing primary infections of ‘national priority’ in South Africa are, of course, HIV and TB. Much of SACEMA’s work has focused on understanding the transmission dynamics of HIV and TB, and their interaction. The deeper point of understanding transmission is to find ways of limiting or, if possible, ultimately eliminating it. Our recent work on tuberculosis has focused on quantifying the mortality burden in South Africa and investigating the potential impact of interventions targeting previously treated individuals.

Source: BBC

The sexually transmitted human papillomavirus (HPV) causes cervical cancer – the second most common cancer and the leading cause of cancer death among South African women. Co-infection with HIV increases risk of progression from infection to cancer. At SACEMA, we have developed an individual-based population-level model to explore HIV and HPV transmission dynamics, and explore different HPV natural history structures. We use this model to estimate the impact that HPV vaccination and cancer screening will have on the incidence of cervical cancer in future.