UOA05-10: Mapping vector-borne diseases to inform global planning for control and elimination
Submitting InstitutionUniversity of Oxford
Unit of AssessmentBiological Sciences
Summary Impact TypeHealth
Research Subject Area(s)
Medical and Health Sciences: Medical Microbiology, Public Health and Health Services
Summary of the impact
Innovative research into the spatial ecology of vector-borne disease at the University of Oxford led
to the setting up of the Malaria Atlas Project (MAP), a programme which has provided
sophisticated models of malaria distribution to inform planning and policy decisions of national
governments and international agencies. MAP data underpinned the 2012 World Health
Organization World Malaria Report and has influenced WHO's policy on malaria. Mapping has also
been used in planning and resource allocation by other key players in the fight against malaria: the
African Leaders Malaria Alliance, the Roll Back Malaria partnership, the Global Fund and the
Global Health Group. More recent research to map the global distribution of dengue risk has been
used in vaccine planning by the GAVI Alliance in conjunction with the Gates Foundation.
Vector-borne diseases constitute some of the biggest threats to global public health. Malaria risk
affects almost half the world's population; the WHO World Malaria Report 2012 estimates that in
2010 there were 219 million cases of malaria and 660,000 deaths. Dengue fever is ranked by
WHO as the most important mosquito-borne viral disease in the world; a 30-fold increase in
incidence over the last 50 years means it now threatens around 2.5 billion people worldwide. The
effective targeting of available resources in order to control and eliminate these diseases requires
accurate and detailed information about their global distribution.
Research led by Professors David Rogers and Sarah Randolph at the University of Oxford's
Department of Zoology investigated the ecology and epidemiology of vector-borne diseases such
as the African trypanosomiases, yellow fever and malaria. A paper published in 1993 was one of
the first to address key factors such as the impact of increasing urbanisation, international trade
and climate change on the global spread of vector-borne diseases. The paper identified the need
for more complex maps of disease distribution that incorporated, for example, satellite data on
weather that might help predict changes in vector distribution1.
A collaboration developed with Professor Robert Snow, Professor of Tropical Public Health at the
University of Oxford, who had also recognised the need to map malaria risk more accurately.
Research published in 1998 by Rogers, Simon Hay (also by this time at the Department of
Zoology) and Snow represented the first attempt to use remote sensing and geographical
information system techniques, in conjunction with data on malaria endemicity to examine the
clinical consequences of vector, parasite and human contact in Kenya. Previous studies had
merely mapped mosquito habitats and predicted insect numbers. The 1998 paper demonstrated
for the first time that a significant correlation existed between the timing of meteorological and
vegetation changes (recorded by satellite sensors) and the relative changes in prevalence of
In 2005 a groundbreaking paper provided an entirely empirical approach to the global distribution
of malaria using a combination of epidemiological, geographical and demographic data3. It showed
that there were an estimated 515 million episodes of clinical Plasmodium falciparum malaria (the
most dangerous form) worldwide in 2002 — up to 50% higher than those reported by WHO, and
200% higher for areas outside Africa. These results reflected the extent to which WHO was relying
on passive national reporting for these countries and revealed Africa as the dominant contributor to
the global burden of malaria, while highlighting a hidden burden in Asia. It also emphasised the
need for an informed understanding of the cartography of malaria risk in order to properly evaluate
the global extent of the disease. The interest generated by this paper led directly to the founding of
the Malaria Atlas Project (MAP) in 20064. The Wellcome Trust provided funding, and in 2009 a
paper was published describing the research behind the first new global malaria map for 40 years,
which showed P. falciparum endemicity in 20075. Hay's novel contribution to this was to apply a
Bayesian statistical framework in order to create continuous spatial estimates of malaria
distribution from the nearly 8,000 fixed-point parasite rate surveys. The research showed that, of
the nearly 1.4 billion people exposed to stable P. falciparum risk worldwide in 2007, around 55%
lived in conditions of very low endemicity with the potential for malaria to be eliminated altogether.
It also identified the areas of high risk where a much more aggressive control strategy was needed.
More recently Professor Hay and his group have expanded the scope of their research to study the
distribution of many different diseases and identify those with the strongest rationale for mapping.
A 2013 paper from the IDAMS Consortium, led by Hay, analysed the global distribution of dengue
fever risk, and used mapping techniques to estimate that there were 390 million dengue infections
per year, of which 96 million manifested clinically — more than three times the dengue burden
estimate of the World Health Organization6.
References to the research
1. Rogers DJ, Packer MJ. (1993) Vector-borne diseases, models, and global change. Lancet
342: 1282-1284. doi: 10.1016/0140-6736(93)92367-3 Paper identifying the need for more
complex maps of disease distribution incorporating remotely-sensed data.
2. Hay SI, Snow RW, Rogers DJ. (1998) Predicting malaria seasons in Kenya using multitemporal
meteorological satellite sensor data. Trans Royal Society of Tropical Medicine and Hygiene 92:
12-20. doi: 10.1016/S0035-9203(98)90936-1 First demonstration of a correlation between
changes in weather and vegetation data obtained from satellites, and relative changes in
prevalence of clinical malaria.
3. Snow RW, Guerra CA, Noor AM, Myint HY, Hay SI. (2005) The global distribution of clinical
episodes of Plasmodium falciparum malaria. Nature 434: 214-217. doi: 10.1038/nature03342
Key paper describing the global distribution of malaria and highlighting areas in which
existing data was inaccurate or missing. Winner of the Research Paper of theYear award
from the Malaria Foundation International in 2006.
4. Hay SI, Snow RW. (2006) The Malaria Atlas Project: Developing global maps of malaria risk.
PLoS Medicine 3: 2204-2208. e473. doi: 10.1371/journal.pmed.0030473 Paper launching
the Malaria Atlas Project, underlining the need for improved maps of malaria distribution
5. Hay SI, Guerra CA, Gething PW, Patil AP, Tatem AJ, Noor AM, et al. (2009) A world malaria
map: Plasmodium falciparum endemicity in 2007. PLoS Medicine 6: 0286-0302. e1000048.
doi: 10.1371/journal.pmed.1000048 Paper describing the research and methods behind the
first comprehensive global malaria map for 40 years.
6. Bhatt S, Gething PW, Brady OJ, Messina JP, Farlow AW, Moyes CL, et al. (2013) The global
distribution and burden of dengue. Nature 496: 504-507. doi: 10.1038/nature12060 First
systematic mapping of the global distribution of dengue fever.
Funding for research: Grants in excess of £4M have been received for this work since 1998 from
the Wellcome Trust, the Bill and Melinda Gates Foundation, the Global Fund and a number of
Details of the impact
The critical impact of Professor Hay and colleagues' research has been in the provision of detailed,
accurate and evolving information about the distribution of vector-borne diseases (particularly
malaria). The information has enabled the more effective targeting of available resources.
Worldwide, control of malaria is high on the political agenda, but WHO estimates that the large
amount of international funding spent each year on control measures (US$2.5 billion in 2010) is
less than half of what is ideally required.
Since the first map of P. falciparum transmission, the Malaria Atlas Project has gone on to develop
increasingly sophisticated models of the spatial and temporal patterns of global malaria, based on
the research described above. MAP, which continues to operate out of the Department of Zoology,
now provides a definitive and continuously updated open access mapping resource describing the
distribution of malaria in every affected country in the world7. The MAP website receives an
average of 70,000 hits from around 216 nations every year (including visits from 97 of the 100
malaria endemic countries), and since 2008, MAP data have been used to help shape malaria
policy and practice. For example, in 2012 the African Leaders Malaria Alliance (ALMA), an alliance
of 49 Heads of State and Government, used analyses based on MAP's open access map of P.
falciparum transmission to explore how effectiveness of insecticide treated nets (LLINs) might vary
from country to country. This analysis highlighted priority areas in Africa for targeting of LLINs and
through the Global Fund (an international financing institution dedicated to attracting and
disbursing resources to prevent and treat HIV/AIDS, TB and malaria) resulted in significant
additional resourcing: 38 million LLINs in two countries, and US$117M for LLINs in three others.
The Chief Technical Advisor to the ALMA Secretariat confirms that the data provided `was vital in
convincing partners as to the seriousness of the situation in the identified countries' and `extremely
useful to ALMA in making the case for targeted investment in filling the LLIN gaps in several
Since 2008, MAP has had its biggest impact in terms of influencing WHO policy on malaria. While
WHO's role is primarily advisory, it is powerfully influential at the level of national governments and
sets the health agenda at a global level. The prevention and control of malaria is, together with
HIV/AIDS and tuberculosis, at the top of WHO's list of priorities. Since 2012 MAP has made
substantial contributions to WHO's annual World Malaria Report9, which is `used widely in
international and national level policy decision making' according to the Director of WHO's Global
Malaria Programme. He also confirms that `as well as their maps of malaria transmission and
estimates of clinical incidence, MAP have provided information on the equitable distribution of
funding for malaria control, the rational distribution of insecticide treated bednets ... and a range of
other analyses provided responsively.' This demonstrates the extent to which WHO considers MAP
data to represent the `gold standard' for malaria mapping. MAP is in the process of becoming a
WHO Collaborative Centre to cement a joint approach to malaria burden estimation10.
MAP data also underpin the strategies of the Roll Back Malaria (RBM) partnership which was
launched in 1998 by WHO, UNICEF, the UN Development Programme and the World Bank, in an
effort to provide a coordinated global response to the disease. For example, the maps used from
March 2010 in several of RBM's `Progress and Impact' reports are provided by MAP, and
Professor Hay was a co-author of the report on `Mathematical Modelling to Support Malaria Control
and Elimination', in which RBM stressed that `mathematical modelling can play a critical role in
navigating complex public health decisions'11. The Global Fund uses MAP numbers and maps to
analyse where interventions are needed, assess the level of intervention required and evaluate
subsequently the usefulness of interventions. In 2012 it collaborated closely with Hay and others
on a comprehensive review of funding for malaria control, which established that current patterns
of funding were inadequate and unequal12.
As well as supplying open-access data, MAP works with interested parties to create maps
revealing specific information. They have been engaged in a large-scale project with the Global
Health Group at the University of California, San Francisco, whose goal is to stimulate practical
international and local action to solve critical health challenges. Supported by grants from the Bill &
Melinda Gates Foundation and ExxonMobil, its Malaria Elimination Initiative aims to identify and
assess the countries which could feasibly become malaria-free in the near future. MAP has
provided in-depth mapping and assessment for all countries that are determining their path toward
malaria elimination and the collaboration has generated two malaria elimination atlases13. The
Director of the Global Health Group states that `the atlases [for which he confirms that MAP
provided the detailed mapping] have contributed to national and regional malaria elimination
strategy, and have strengthened political and financial support for malaria elimination'14.
Recent research into the global distribution of dengue fever risk has already led to a significant
impact with the GAVI Alliance, a public-private partnership focused on increasing access to
immunisation in developing countries. Detailed maps were produced to show levels of dengue risk
in all 54 GAVI-eligible countries, and to identify where data were in most urgent need of update to
improve dengue burden predictions15. In conjunction with the Gates Foundation, GAVI has used
the results of the research to inform its planning strategy; the Senior Program Officer for Neglected
Infectious Disease at the Bill & Melinda Gates Foundation states that Hay's work `has helped build
the evidence base that the Bill & Melinda Gates Foundation, in partnership with GAVI alliance and
others, is using to evaluate the pros and cons of including a future dengue vaccine to its vaccine
portfolio for developing countries. Our strategy development has been guided and informed by
having this robust data platform'16.
Sources to corroborate the impact
7. Malaria Atlas Project. Available from: http://www.map.ox.ac.uk/ The MAP website is the
gateway to the assembled data and cartographic products widely available in the public
domain (>3000 available). Data on website hits can be corroborated by staff at the
Department of Zoology.
8. Supporting statement from the Chief Technical Adviser to the ALMA Secretariat, confirming the
contribution that MAP data made to effective and efficient malaria prevention and control
interventions in Africa (held on file).
9. WHO's World Malaria Report 2012 (held on file), and also available for download from
http://www.who.int/malaria/publications/world_malaria_report_2012/en/ Corroborates in the
Acknowledgements pages the contributions made by MAP.
10. Supporting statement from the Director of WHO's Global Malaria Programme, corroborating the
contributions made by MAP to WHO documents and decisions (held on file).
11. Roll Back Malaria Progress and Impact Series. Available from:
http://rbm.who.int/ProgressImpactSeries/ (also held on file). In addition to key cited report,
MAP data is used in `Defeating Malaria in Asia, the Pacific, Americas, Middle East and
Europe' and `A Decade of Partnership and Results'.
12. Pigott DM, Atun R, Moyes CL, Hay SI, Gething PW. (2012) Funding for malaria control 2006-
2010: a comprehensive global assessment. Malaria J. 11: 246. doi: 10.1186/1475-2875-11-246
Review examining the way malaria control funding is allocated, confirming financial
support from the Global Fund, and also close collaboration: co-author Professor Rifat
Atun was Head of Monitoring and Evaluation at the Global Fund when the review was
13. University of California, San Francisco Global Health Group. Publications — Malaria Elimination
Group 2009. Available from: http://www.malariaeliminationgroup.org/publications Both the
Atlas of Malaria Eliminating Countries 2011 and the Atlas of the Asia Pacific Malaria
Eliminating Network are confirmed as having been produced in partnership with MAP.
14. Supporting statement from the Director of the Global Health Group, University of California,
San Francisco (held on file), corroborating the significant contribution made by MAP to the
atlases detailed in reference 13.
15. Messina JP, Brady OJ, Hay SI. Dengue risk and burden estimates in GAVI countries. Spatial
Ecology and Epidemiology Group, Department of Zoology, Oxford University. Available from:
13).pdf Hay and colleagues' detailed mapping of the dengue burden worldwide.
16. Letter from Senior Program Officer for Neglected Infectious Disease at the Bill & Melinda Gates
Foundation, corroborating the contribution Hay's research made to their dengue strategy.