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

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

© Francis Schaffner/IPZ

Dr Raman VelayudhanCoordinator, Vector Ecology and Management unitControl of Neglected Tropical DiseasesWorld Health OrganizationGeneva

Average /number of Dengue cases reported to WHO per year

2010 2011 2012 20131995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

0

500000

1000000

1500000

2000000

2500000

3000000

Number of cases recorded from four WHO regions

EMR

AMR

WPR

SEAR

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 20110

500

1000

1500

2000

2500

3000

3500

4000

4500

995

1747 16541820 1786

2453

1828

3267

2292

3484

4248

2798

YEAR

Num

ber o

f dea

ths

repo

rted

Number of Dengue deaths reported to WHO per year

Malaria 1 DengueWHO 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 20132) http://www.pdvi.org/about_dengue/GBD.asp and Brady et.al. PLoS Negl Trop Dis 2012; 6: e1760

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

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

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).

Return of old foes

Public Health 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)

Global/Regional response

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

The global strategy for dengue prevention and control (2012- 2020)

► 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!)

Regional framework

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

World Health Day 2014Vector-borne diseases11

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

High Political impact

Disastrous Disease consequences

Source: internal disease ladder exercise conducted in Q4 2010 by Sanofi Pasteur Dengue teams

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

Dengue, advocacy

Public health action

3 phases of vector and disease prevention and control

• Control the vector

• Prevent the disease

• Limit the spread

World Health Day 2014Vector-borne diseases14

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

World Health Day 2014Vector-borne diseases15

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

World Health Day 2014Vector-borne diseases16

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

World Health Day 2014Vector-borne diseases17

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

World Health Day 2014Vector-borne diseases18

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

World Health Day 2014Vector-borne diseases19

Current challenges

• Emerging insecticide resistance

• Lack of expertise in vector control

• Integrated surveillance

• Sanitation

• Pesticide safety

• Environmental change

World Health Day 2014Vector-borne diseases20

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)

21

Thank you