Threat of dengue in Europe and strategic measures to control its spread

1. Threat of dengue in Europe and strategic
measures to control its spread
© Francis Schaffner/IPZ
Dr Raman Velayudhan
Coordinator, Vector Ecology and
Management unit
Control of Neglected Tropical Diseases
World Health Organization
Geneva

2. Average /number of Dengue cases reported
to WHO per year
3000000
2500000
2000000
1500000
1000000
500000
0
2010 2011 2012 2013
Number of cases recorded from four WHO regions
EMR
AMR
WPR
SEAR
1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

3. Number of Dengue deaths reported
to WHO per year
4500
4000
3500
3000
2500
2000
1500
1000
500
0
995
1747 1654
1820 1786
2453
1828
3267
2292
3484
4248
2798
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Number of deaths reported
YEAR

4. Malaria 1 Dengue
WHO RECENT 2
Population at risk 3.2 billion 2.5
billion
3.9 billion
Endemic countries 97 >100 128
Infections /year 219 million 50-100
million
390
million
Severe Cases 3 million 2.1 million
Deaths/ year 627,000 20,000 21,000
1) Global Malaria Report 2013
2) http://www.pdvi.org/about_dengue/GBD.asp and Brady et.al. PLoS Negl Trop
Dis 2012; 6: e1760

5. Some historical reports of large outbreaks in
Europe, with Aedes spp. as vector.
► Dengue epidemic, Greece, 1927–1931*
The total number of deaths from the epidemic ranged from 1 in cities like
Giannitsa or Tripolis to 631 in Athens.
► 19th century yellow fever epidemics (Spain, France, UK) **
Barcelona, Spain, 1821: estimated 20,000 deaths
* Louis C. Daily newspaper view of dengue fever epidemic, Athens, Greece, 1927–1931. EID Journal,
2012, 18 (1).
** Morillon M. et al. Yellow Fever in Europe during the19th Century. In Ecological Aspects of Past
Settlement in Europe, European Anthropological Association, 2002 Biennal Yearbook. Eötvös University
Press, Budapest. p 211-222

6. Increased activity of mosquito-borne
diseases (Aedes spp.) in Europe
► Chikungunya virus outbreak, Ravenna, Emilia-Romagna
region, Italy, July–September 2007 (257 cases)
► First 2 autochthonous dengue virus infections, Nice, France,
September 2010
► First autochthonous dengue virus infection, Pelješac, Croatia,
August 2010
► First dengue fever outbreak, Madeira, Portugal,
September 2012 – February 2013 (2164 cases)
►Dengue in France, Montpellier (October 2014)
Sharp increase in number of imported dengue cases in UK and
Switzerland

7. Return of old foes
The history of dengue and yellow fever in Europe is evidence that
conditions are already suitable for transmission. The establishment of
Ae. albopictus has made this possible, and the possibility will increase
as the species expands northwards, or if Ae. aegypti is re-established.
In Europe, dengue cases are second only to malaria in causing
hospitalizations of travellers (imported cases)
Source: Reiter P. Yellow fever and dengue: a threat to Europe? Eurosurveillance,
2010, 15(10) (http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=19509).

8. Public Health Response
Global/Regional response
► Global strategy for dengue prevention and
control, 2012–2020
► WHO meetings on invasive mosquito species,
The Hague, Netherlands (June 2012) and Copenhagen, Denmark
(November 2012 and May 2013)
► Technical support (e.g. European Centre for Disease Prevention and
Control (ECDC) mission, Madeira, 2012)
► WHO Regional Office for Europe framework for surveillance and control
of invasive mosquito vectors and re-emerging vector-borne diseases
(reviewed by Standing Committee of the Regional Committee, March 2013)

9. The global strategy for dengue prevention and control (2012- 2020)
Goal: To reduce the burden of dengue
Objectives:
• To reduce dengue mortality by at least 50% by 2020*
• To reduce dengue morbidity by at least 25% by 2020*
• To estimate the true burden of the disease by 2015
Technical element
1: Diagnosis and
case management
Technical element
2:
Integrated
surveillance and
outbreak
preparedness
Technical
element 3:
Sustainable
vector control
Technical
element 4:
Future
vaccine
implementation
Technical element
5:
Basic operational
and
implementation
research
Enabling factors for effective implementation of the global strategy:
 Advocacy and resource mobilization;
 Partnership, coordination and collaboration;
 Communication to achieve behavioral outcomes;
 Capacity building; and
 Monitoring and evaluation

10. Regional framework
► Framework for action, in line with Health 2020
► Intersectoral, building on partnerships (e.g. ECDC, European Mosquito Control
Association (EMCA), the Netherlands); EURO/EMRO collaboration.
► Aims
 Raising awareness
 Integrating surveillance
 Preventing introduction
 Preventing disease transmission
 Capacity building: regional networks and human
resource development (e.g. entomologists!)

11. WHO response
European and global commitments
• Regional framework for surveillance and
control of invasive mosquito vectors and
re-emerging vector-borne diseases, 2014–
2020
• Executive board of WHO Jan 2015
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11 Vector-borne diseases

12. High
Political impact
12
Dengue, avenues for advocacy
● A growing threat to public
health
● Generates distress among
citizens
● High economic costs for
governments and citizens
● Disrupts national health
systems
● Impacts tourism & overall
economy
● Contributes to human suffering &
poverty on a global scale
● High medical need remains
unaddressed
● Negative impact on health
authorities performance
● Increases media, civil society &
international community pressure
on government's performance
● Public discontent
Disastrous
Disease consequences
Source: internal disease ladder exercise conducted in Q4 2010 by Sanofi Pasteur Dengue teams

13. Dengue, advocacy
Factors contributing to a high
sense of priority
• Broad geographic distribution &
spread
• Frequent occurrence of
outbreaks
• Recurrent risk of infection each
transmission season
• Disease severity & difficulty of
diagnosis & management
• Urban outbreaks
• Burden on hospitals & public
health infrastructure
• Economic toll on governments
& families

14. Public health action
3 phases of vector and disease prevention
and control
• Control the vector
• Prevent the disease
• Limit the spread
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15. Phase 1. Control the vector (1)
• Integrated vector control to prevent the introduction,
establishment and spread of the vector
• Measures for early detection and containment
• Robust methods for monitoring and evaluation
• Social mobilization for vector control
• Information for the public on how to
reduce vectors in the environment
through risk communication and
community mobilization
• Increased capacity for vector control
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16. Phase 1. Control the vector (2)
Advice on:
• long-lasting insecticide-treated bed
nets (where necessary)
• indoor residual spraying
• outdoor spraying
• environmental management
(reduction of breeding habitats,
biological control, genetic control
and waste management)
• housing modifications
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17. Phase 2. Prevent the disease
Action needed where the introduction of
vectors could not be avoided
• Coordination of disease surveillance in the
population at risk is with vector surveillance, to
prevent outbreaks
• Advice on personal protection measures
(clothing, insect repellents, etc.), prevention,
and source reduction
• Blood and body fluid safety
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18. Phase 3. Limit the spread
Measures to avoid large outbreaks, particularly
in newly affected areas
• Inform and educate the public
• Raise awareness among health professionals
• Ensure laboratories are equipped
for early diagnosis
• Ensure early detection and case
management
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19. Individuals and families can
contribute
• Know which vectors carry disease
• Use proven vector-control tools
• Cooperate with local authorities in
vector control
• Take part in health education in the
community
• Ensure environmental management
around and in homes
© Francis Schaffner/IPZ
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19 Vector-borne diseases

20. Current challenges
• Emerging insecticide resistance
• Lack of expertise in vector control
• Integrated surveillance
• Sanitation
• Pesticide safety
• Environmental change
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20 Vector-borne diseases

21. WHO Regional Office for Europe
response
• Working with partners including the European
Commission, the European Centre for Disease
Prevention and Control (ECDC) and the European
Mosquito Control Association (EMCA)
• Assisting countries in disease surveillance,
prevention and control, following the International
Health Regulations
• Providing training and guidelines on case
management and vector control
• Advocacy for surveillance of mosquitoes (ECDC)
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22. Thank you