Transcript Document 439486

Symposium on Vector Biology, Ecology and Control:
Celebration of Professor Mir Mulla's 50 Years at Riverside
Strategic Considerations for Global Tropical
Disease Research:
Continued need for innovative vector research
Robert Ridley (Director WHO/TDR)
Symposium on VBEC
HMI, Riverside, CA May 29-June 1, 2007
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Publications demonstrate need for:
• Investment in health to alleviate poverty
• Investment in Research to ensure advances
in health and appropriate policy decisions
• Investment in capacity building so research
sustainable and can be driven by DEC's
Symposium on VBEC
HMI, Riverside, CA May 29-June 1, 2007
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Critical trends
in global research environment
Epidemiological
Changes
Infectious
disease burden
remains high
Growing regional
variation
Enhanced
research
capabilities in
DEC's
Global research
environment for
tropical diseases
DEC's left
behind in
priority setting
Complexity and
fragmentation
Momentum
through new
players / initiatives
Rise in
pharmaceutical
product
development
Symposium on VBEC
HMI, Riverside, CA May 29-June 1, 2007
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Vision
An effective global research effort
on infectious diseases of poverty
in which disease endemic
countries play a pivotal role
Symposium on VBEC
HMI, Riverside, CA May 29-June 1, 2007
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Implications for TDR
 To foster the vision
 To focus activity where there is need and
where TDR has a comparative advantage
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HMI, Riverside, CA May 29-June 1, 2007
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Modelling the system to address TDR's role
Empowerment, pivotal role …
EDCTP
GAELF
MMV
Grand Challenges
New
New
knowledge /
knowledge /
discoveries
NIH, Trust,
discoveries
Research
councils, etc…
Trachoma
Microbicides
New
and
DNDi
improved
tools
GATB
IAVI
New and
improved
interventions
RBM
New and
improved
strategies
StopTB
Global Fund
APOC
FIND
Stewardship, effective global effort ..
Symposium on VBEC
HMI, Riverside, CA May 29-June 1, 2007
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Implications
New
knowledge /
discoveries
New and
improved
tools
Foster innovation for
products,
emphasizing DEC
engagement
New and
improved
interventions
Foster research to
develop and evaluate
interventions in
real-life settings
New and
improved
strategies
Foster research
for access to
interventions
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HMI, Riverside, CA May 29-June 1, 2007
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Working with all stakeholders to achieve
Innovation
Interventions
Access
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HMI, Riverside, CA May 29-June 1, 2007
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Business Lines and Gaps
Capacity,Empowerment
Empowerment, led by
BL 4: Innovation
for PD in DEC
BL 11: Integrated
delivery strategies
BL 9: Malaria/fever treatment policy
BL 8: Treatment for HIV/TB
BL 3: Discovery
BL 7: Drugs for helminths
BL 6: Diagnostics
BL 10: VL elimination
BL 5: Innovative vector control
Effective global
effort, Stewardship…
Stewardship
Symposium on VBEC
HMI, Riverside, CA May 29-June 1, 2007
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Business Lines – vector related
Capacity,Empowerment
Empowerment, led by
BL 4: Innovation
for PD in DEC
BL 11: Integrated
delivery strategies
BL 10: VL elimination
BL 5: Innovative vector control
Effective global
effort, Stewardship…
Stewardship
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HMI, Riverside, CA May 29-June 1, 2007 10
Outline of the presentation
• Global perspectives, issues and challenges
for control of vector-borne diseases
• TDR contribution to vector-borne disease
research
• Some critical issues for future direction of
vector research for tropical diseases
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Global perspectives, issues and
challenges for control of vector-borne
diseases
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Vector-borne diseases affect about half of
world's population
• They occur in more than 100 countries, affect nearly
half of the world's population, and result in high
morbidity and mortality
• They are responsible for more than 500 million
clinical cases per year (nearly one person in ten).
Their total burden is about 56 million Disability
Adjusted Life Years (DALYs).
• Malaria remains the dominant disease globally
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Climate Change and Human Health. 2002. by A.J. McMichael, D.H. Campbell-Lendrum, C.F. Corvalán, K.L. Ebi, A. Githeko,
J.D. Scheraga and A. Woodward, 2003, 322 pages: http://www.who.int/globalchange/publications/climchange.pdf, p. 50
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http://www.who.int/globalchange/en/
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The Economist, 12 May 2007, p. 41
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Progress in reducing the global burden of malaria has been slow
GLOBAL STATUS
.Deaths: 1.09 million annually
(most deaths occur in children
under the age of 5)
.Cases: 550 million clinical cases annually
.Disease burden: 44.99 DALYs)
. At risk: 40% of the global population (>2.1 bn)
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HMI, Riverside, CA May 29-June 1, 2007 17
Continent-wide distribution of malaria burden
Africa
Asia
Americas
Estimated proportion of
population at risk
66%
49%
14%
Estimated contribution to the
global burden of clinical cases
59%
38%
3%
Estimated contribution to the
global mortality burden
89%
10%
<1%
http://rbm.who.int/wmr2005
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Research Priorities
• New tools (to address resistance)
– Drugs, diagnostics, vaccines, insecticides (IRS, ITN,
other)
• How to use these tools effectively
– Dosing, packaging, rotation, combination into
packages
• How to ensure interventions are accessed in
poor settings
– Distribution mechanisms, community approaches
•
Cost effectiveness of interventions and impact
– Health economics, burden of disease measurements
etc.. ,
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Dengue: Annual DHF cases
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Other Vector-Borne Diseases
• African
trypanosomiasis
• Chagas disease
• Leishmaniasis
• Lymphatic filariasis
• Onchocerciasis
• (Schistosomiasis)
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Human African Trypanosomiasis (HAT)
• Control limited by reduced vector control efforts and
inadequacy of other existing interventions e.g., drugs are not
adequate.
• Several vector control methods (traps, screens, application
of insecticides on traps or livestock, sequential aerial
application of insecticides, sterile insect technique, and
community-based vector control interventions) were
developed over the years, but …
– Are they optimised?
– Can they be scaled up cost-effectively and sustainably?
• Opportunities for new tools?
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Chagas disease
• Successful vector control achieved in the Americas
based on the application of insecticides to control
domestic triatomine populations.
• However, this approach has been ineffective
against the invasion of bugs from peridomestic and
sylvatic areas.
• New tools and approaches needed that prevent reinfestations of triatomine populations.
– genetically-engineered bacterial symbionts and biological
control agents?
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Need for integrated vector management approach
•
Integrates all available resources to
achieve a maximum impact on vectorborne disease.
•
Evidence-based requiring capacity to
generate local data on disease
epidemiology and vector ecology.
»
•
Collaboration within the health sector and
with other public and private sectors that
impact on vectors.
»
•
Engagement with local communities and
other stakeholders;
»
•
A public health regulatory and legislative
framework.
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Continued need for innovation
• Environmental management for integrated vector control
• Tool development (chemical and non-chemical) for vector control
– Exploiting advances in biotechnologies for the development of improved
vector control tools and strategies
– Vector genetic transformation as a potential method for vector control
• Research on cost-effective delivery
• Translating research findings into policy and action
• Building capacity in disease endemic countries for the exploitation of new
technologies
• Need for $$$$$$$$$$$?
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Some TDR contributions and future
perspectives on Vector Research
www.who.int/tdr for more publications
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Some contributions
• 1982: Onchocerciasis - Bacillus thuringiensis israelensis H-14 in
disease control use for blackfly control of onchocerciasis at critical
moment to counter pesticide resistance
• 1989: African trypanosomiasis - Insecticide impregnated tse tse fly traps
in disease control use. (biconical and monoconical)
• 1990: Chagas disease - Fumigant canisters, insecticidal paints and
Triatomine detection boxes in disease control use
• 1991: Onchocerciasis - DNA probes for Onchocerca volvulus (OCP) in
control use
• 1991: Malaria – Tucson meeting initiates activity on genetically modified
mosquitoes
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Some contributions
• 1994: Malaria - Insecticide-impregnated bednets in disease control use
following results of large-scale trials in Africa showing 20% mortality
reduction.
• 2002: Malaria - Genome sequencing of Anopheles gambiae completed
by TDR-fostered consortium and announced simultaneous to the
sequencing of Plasmodium falciparum).
• 2004: African trypanosomiasis -A TDR-led consortium of organizations
form the International Glossina Genomics Initiative (IGGI) in an
international effort to fully sequence the tsetse fly genome
• 2005: Methodology to facilitate pupal surveys for dengue
• 2006: Evidence that community directed provision of bednets can
demonstrably enhance uptake
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Genetically modified vectors
Malaria (since 1994),
Dengue (added in 1999)
and HAT (added in 2006)
Catteruccia, Nature, 2000:
A. stephensi transformed using Minos TE
Grossman et al., Insect Molec. Bio. 2001:
A. gambiae transformed using piggyBac
Ito et al., Nature, 2002; Ghosh et al., PNAS, 2001
Mosquitoes refactory to P. berghei
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HMI, Riverside, CA May 29-June 1, 2007 31
Training Courses and Consultation
ICIPE – July 2004
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Recent TDR publications on dengue
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Achievement – Entomological sampling for Dengue

Pupal and demographic surveys enable assessment of dengue
vector densities and threshold levels for Dengue transmission

Pupae serve as proxy for adult mosquitoes

Allows focus on most productive containers making surveys more
cost effective

Multi-country study validates hypothesis
Traditional view:
Bottles
main source
Round tanks
Tires
Bottles
Other tanks
Trays
Div. Medium
Div. Small
Div. Large
Don't know
Revised view:
Round tanks
Tyres
main source
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Insecticide Treated Curtains Can Reduce Dengue
House index (% of infested houses)
presented as an example from Mexico.
Blue bars representing nearby control
clusters "benefit" from intervention clusters .
Far away external control clusters
show unchanged vector densities.
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Elimination of visceral leishmaniasis on
Indian sub-continent
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Integrated community directed interventions
• Many (APOC) countries
familiar with CDTivermectin
– Takes 5 years for APOC to
introduce sustainably
– Over 100,000 communities
engaged
– 60 million reached
– 100 million by 2010
• Can this CDI be expanded
and more broadly utilised?
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HMI, Riverside, CA May 29-June 1, 2007 38
Community engagement and ownership of distribution
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Underfive children sleeping under an ITN
the night before the interview
Underfive children sleeping
under an ITN last night (%)
RBM
target
60
P<0.001
50
40
35.1
30
20
9.1
10.7
10
0
Comparison district,
classical ITN
CDI district, but
classical ITN
ITN through CDI
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HMI, Riverside, CA May 29-June 1, 2007 40
Ivermectin Treatment Coverage
P<0.001
Treated with ivermectin (%)
80
70
71
73.5
APOC
target
61.1
60
50
40
30
20
10
0
Comparison
districts
CDI districts,
Vitamin A + ITN
CDI districts,
HMM + DOTS
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Some critical issues for vector research
• Impact of climate change and water management
• Resistance to insecticides
• Integration of vector control into combined, multidisease interventions
• Sustainability of vector control interventions
• Entomology capabilities, especially in developing
countries
• Managing innovation through multi-disciplinarity of
future research
• Interface between research, control and policy
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HMI, Riverside, CA May 29-June 1, 2007 42
Vision
An effective global research effort
on infectious diseases of poverty
in which disease endemic
countries play a pivotal role
Symposium on VBEC
HMI, Riverside, CA May 29-June 1, 2007 43