Peter Piot Institute for Global Health 4 th December 2009 What I wish modelling could do for global health

ColonialPost-colonialEnd of cold war Globalisation Tropical medicine Geographic medicine International Health Global Health

[i] data: Extracted from 2006 Report on the Global AIDS Epidemic (UNAIDS, 2006) [ii] data: AIDS in the World II. Edited by Jonathan Mann and Daniel J. M. Tarantola (1996) Notes:[1] figures are for international funds only [2] Domestic funds are included from 2001 onwards Funding Total annual resources available for AIDS, 1986 ‒ US$ million billion Signing of Declaration of Commitment on HIV/AIDS, UNGASS ‘96‘97‘98‘99 ‘00 ‘01‘02‘03‘04‘051986‘87‘88‘89‘90‘91‘92‘93‘94‘95 Less than US$ 1 million World Bank MAP launch Global Fund PEPFAR 257 UNAIDS Gates Foundation ‘ billion 10 billion

Modelling for Global Health Interpretation Prediction and anticipation Creation of hypothesis Implications of policy options Evaluation Identification of data needs Advocacy

Behavioural change, impact in urban and semi- urban Zimbabwe Source: Hallett TB, et al. Epidemics 2009;1(2): Natural decline in incidence ~1990 Accelerated decline in incidence, due to behaviour change ~2000 M 0 : without behavioural change M 1 : assuming behavioural change, better fit to surveillance data

Cambodia, Number of new HIV infections by route of transmission Source: Peerapatanapokin and Brown, using Asia Epidemic Model

Real-time modelling FMD, SARS showed the potential of real-time modelling (statistical and dynamical). Initial goal – ‘now-casting’ – correcting for censorship/delays in case/mortality reporting Aims – estimate R, mortality, generation time distribution, predict future trends, evaluate sufficiency of control measures. Important new approach – inferring infection trees – developed in 2001 then further in 2003 for SARS. Require data though – need to set realistic expectations

Prediction and anticipation

World population by age groups, Source: United Nations Population Division “World Population Prospects: The 2006 Revision”

Predicted expansion of dengue in Africa This projection uses an scenario that delivers a three fold increase in CO 2 by 2100 Source: Hales S et al. Lancet. 2002;360(9336),

Geographic origins of emerging infectious diseases events from 1940 to 2004 Source: Jones KE et al. Nature 2008:451;

AIDS spending (share of gross domestic product) and adult HIV prevalence in 2030 Source: Hecht R et al. Health Affairs 2009;28(6):

Population impact of treatment as prevention Source: Granich RM, et al. Lancet 2009; 373: 48–57. Time trends resulting from application of universal voluntary HIV testing and immediate ART strategy for people who test HIV positive, in combination with other adult prevention interventions that reduce incidence by 40%

Policy impact of treatment as prevention Source: Bulletin des médecins suisses | Schweizerische Årztezeitung | Bolletino dei medici svizzeri | 2008;89:5 and

Policy options

Hep B vaccination strategies in the Netherlands Source: Kretzschmar M et al. Lancet Infectious Diseases 2008;8(2):  Will it be possible to increase coverage of risk groups to acceptable levels or is universal vaccination the way to ensure satisfactory vaccination coverage of high-risk groups? Universal vaccination of all neonates or all adolescents has the greatest potential at the cost of having to vaccinate large numbers of individuals Targeting vaccination to high-risk groups can be cost effective, despite being demanding in effort and logistics.

HPV vaccination - need for continued screening and appropriate health-care messages Source: Garnett GP et al. Vaccine 2006;24(3):S178-S186.

Long term view: Effects of Prevention on Future Costs of ART

Interaction of circumcision interventions with existing behaviour change programmes Source: Hallett TB, et al. PLoS ONE 2008;3(5): e2212 Projected effect of different prevention interventions on HIV incidence

Source: Jansen VAA, et al. Science 2003;301:904. Measles outbreaks in a population with declining vaccine uptake

Synergy needed Science Politics Money Programme delivery Source: Koplan JP et al. Lancet 2009;373:1993.

Recorded female deaths in South Africa and Brazil for ages years Source: Nathan Geffen. Statistics South Africa and Instituto Brasileiro de Geografia e Estatistica. Brazil, 2004.South Africa, 1997.South Africa, 2004

Need for real-life effectiveness evaluations Seguro Popular is a new set of health reforms aiming to provide health coverage to 50 million uninsured Mexicans. 23% reduction from baseline in catastrophic expenditures 30% reduction in poor households and 59% in experimental compliers Source: King G et al. The Lancet 2009: 373(9673):

Concurrent partnerships have been hypothesised as one of the main factors behind the HIV epidemics in sub-Saharan Africa for the past 15 years, with empirical evidence providing different conclusions. It was only a few days ago that the Working Group on Measuring Concurrent Sexual Partnerships (UNAIDS Reference Group on Estimates, Modelling, and Projections) published a consensus paper on indicators for concurrency. The Lancet, article in press: doi: /S (09) doi: /S (09) Data Needs: Concurrency and HIV Source: Morris M et al. AIDS 1997;11(5):

Source: Bollinger et al. Journal of the International AIDS Society :7. Total net cost of male circumcision programme (US dollars) Advocacy : cost and impact of male circumcision New adult HIV infections by scenario

A new agenda for global health New challenges for modellers Finalize the unfinished agenda! Chronic diseases and mental health Population growth, climate change, urbanization, water Deliver new prevention& treatment technologies More effective health systems

Projected deaths by cause for high-, middle-, and low-income countries Source: WHO World Health Statistics

Network analysis of obesity in the Framingham cohort Source: Christakis NA et al. NEJM 2007:357(4); Largest connected subcomponent of the social network in the Framingham Heart Study in Probability that an ego will become obese according to the type of relationship

Megacities of the world in 2015

What do we need more from modellers? Explore connections between disease dynamics and structural determinants Use more than one modelling approach per issue Regularly validate past and present modelling Engage with evaluation of complex health interventions to generate counterfactuals against which to compare observed trends.