Contact details

Dr T Deirdre Hollingsworth

Junior Research Fellow
Division of Epidemiology, Public Health and Primary Care

Norfolk Place
St Mary's Campus

Tel: +44 (0)20 7594 3217
Email:

Dr Deirdre Hollingsworth

I am an Imperial College Junior Research Fellow in infectious disease epidemiology. The main focus of my research is developing mathematical models to inform the design of effective public health interventions for malaria.

Malaria

In recent years there has been a resurgence of efforts to mitigate the mortality due to malaria with the ultimate aim of eradication. I am currently developing models of endemic malaria transmission in areas of Africa to identify strategies which will be effective under particular local conditions.

Immunity to malarial disease develops with repeat infection, resulting in low rates of disease in the highest transmission areas and high rates of disease for intermediate levels of transmission. This interaction between infection, immunity and disease complicates the prediction of the long term impacts of intervention policies. Mathematical models can be used both to test hypotheses about these interactions and to inform the design of effective intervention strategies.

HIV

I also work with Professor Christophe Fraser  on models of HIV transmission which consider variability in the life history of disease and the implications for evolution and control.  We have developed epidemic models of HIV which study the evolution of virulence and the importance of the short period of high infectivity at the outset of an HIV infection (acute and primary infection) in transmission of the disease.

Emerging infections

Public health control policies for the containment of novel outbreaks and any future influenza pandemic have been strongly influenced by mathematical models. Reanalysis of data from the SARS outbreak in 2003 with Professor Roy Anderson, Professor Christl Donnelly and in collaboration with  Don Klinkenberg and Hans Heesterbeek  at the University of Utrecht has improved our understanding of outbreak dynamics and key issues and consequences for pandemic planning.

Travel advisories

The WHO issued several travel advisories during the course of the 2003 SARS epidemic, advising avoidance of non-essential travel to affected areas. These were controversial because of their adverse economic impact and the uncertainty about their effectiveness. International airlines reported serious drops in passenger numbers, but the change was gradual (Fig 1). In the event of a potential influenza-A pandemic, control is only possible within days of an outbreak. If within-country control measures fail following the emergence of a potentially pandemic variant of influenza, our analysis shows that only complete travel restrictions, rapidly implemented, will have a major impact on global spread.

Figure 1 Daily SARS case number in 2003 (thin red bars) and monthly daily percentage change (over previous year) in passenger volume (thicker bars). Four air passenger datasets are shown: global passengers (black), Asia-Pacific passengers (red), Hong Kong airport passengers (green) and Beijing international Airport (yellow). For further details see Hollingsworth et al Nat. Med. (2006).

Background

Before moving to Imperial I did a PhD in mathematical modelling of fungal growth through soil, supervised by Adrian Stacey and Professor Chris Gilligan, in the Epidemiology and Modelling Group within the Department of Plant Sciences, University of Cambridge. I investigated the effect of soil structure on fungal growth using stochastic models of the soil pore network (Figure 2). Prior to my PhD I did an MSc in Mathematical Modelling and Numerical Analysis, supervised by Andrew Fowler, and a BA  in Mathematical Sciences, both at Lincoln College, Oxford University. Between these two degrees I did an MMus (Master of Music) in 'cello performance.

 Figure 2 Abstracting a soil pore space (left) into a network of pores (right - spheres) and throats (cylinders) such that the pore network represents the physical structure of the soil

Teaching

I teach on the MSc in Modern Epidemiology and Imperial College’s professional short course, Introduction to Mathematical Models of the Epidemiology & Control of Infectious Diseases, which is aimed at public health professionals, policy-makers, researchers and health economists who want to learn about the basic principles and practical applications of mathematical modelling and modern quantitative methods.