I studied mathematics at the Universities of Mainz and Tübingen, Germany, followed by a doctorate in mathematics on a topic from biomathematics. After gaining my doctorate, I carried out post-doctoral work in the United States (Cornell University), Scotland (Strathclyde University, Glasgow), and the Netherlands (Centre for Mathematics and Informatics, Amsterdam). Presently, I hold a joint appointment as a professor of dynamics of infectious diseases at the Julius Centre for Health Sciences and Primary Care, University Medical Centre Utrecht, and as a chief science officer for mathematical disease modelling at the National Institute for Public Health and the Environment (RIVM), Bilthoven, both in the Netherlands.
A main focus of my research has been on transmission dynamics and intervention impact in sexually transmitted infections and HIV. More broadly my research involved the impact of sexual network structure on the transmission of sexually transmitted diseases and HIV. I have used individual based modeling approaches for describing dynamic network structure and its effects on transmission of HIV, chlamydia, and gonorrhea. I have also developed modeling approaches to study the impact of concurrent partnerships on HIV transmission dynamics. I contributed to the development of deterministic pair formation models that are used for modeling HIV and chlamydia infections and studied the impact of partnership duration on HIV transmission in deterministic models. The other main focus of my research has been on studying contact patterns and their relationship with transmission of infection. This could be sexual contacts as stated above, but also close contacts such as conversational contacts that are related to transmission of respiratory infections. In a recent project, we pioneered the use of respondent driven sampling methods for collecting contact network information. Finally, I have developed methodology for estimating disease burden for infectious diseases using disability adjusted life years and taking into account long term sequelae of acute infections. My aim has always been to gain understanding of the dynamics of infectious disease transmission in order to improve response and control strategies. My work is strongly interdisciplinary and bridges mathematics, epidemiology and public health.