Takken-KNMVD2015 [Compatibility Mode]

IMPORT OF VECTORS AND VECTOR-BORNE
DISEASES
Prof. Willem Takken
Laboratory of Entomology
Wageningen Universiteit en Research Centrum
The plague
The approximate sequence of spread of bubonic plague (The
Black Death) in Europe, between its entry from Asia in 1346 and
its eventual spread, via the Baltic region, into Russia in 1348.
Around one-third of the European population perished.
Louse-borne typhus
Published:
1994
Sleeping sickness
Dengue
Malaria
Plague
Lyme disease
Tick-borne encephalitis
Chikungunya
Human vector-borne diseases with risk for
travelers
Malaria
Dengue
Yellow fever
Leishmaniasis
African trypanosomiasis
Chagas disease
West Nile virus
Chikungunya
Lyme borreliosis
Tick-borne encephalitis (TBE)
Rickettsiae fevers
Mosquitoes
Mosquitoes
Mosquitoes
Sandflies
Tsetse flies
Bloodfeeding bugs
Mosquitoes
Mosquitoes
Ticks
Ticks
Ticks
Human vector-borne diseases with risk for
travelers
Malaria
Dengue
Yellow fever
Leishmaniasis
African trypanosomiasis
Chagas disease
Japanese encephalitis
West Nile virus
Chikungunya
Lyme borreliosis
Tick-borne encephalitis (TBE)
Rickettsiae fevers
Extent of risk
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*
*
*
**
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Human vector-borne diseases in Europe
Malaria
Leishmaniasis
Plague
Yellow fever
West Nile virus
Chikungunya virus*
Dengue**
Typhus
Lyme borreliosis
Tick-borne encephalitis (TBE)
Toscana virus meningitis
Human granular ehrlichiosis
Rickettsiae fevers
Bartonella
* first time in Europe in 2007
** first time in Europe in 2010
Mosquitoes
Sandflies
Fleas
Mosquitoes
Mosquitoes
Mosquitoes
Mosquitoes
Body lice
Ticks
Ticks
Sandflies
Ticks
Ticks
Body lice
Emerging VBD threats for travelers in Europe
Disease
Vector species
Distribution
Occurrence in
Europe
Control possible?
Leishmaniasis
Sandfly
(Phlebotomus
spp.)
Mediterranean
countries
common
Treatment of
infected hosts
Tick-borne
encephalitis
Ixodes ricinus
Central and
Northern Europe
common
Vaccination
Rickettsiosis
Ixodes ricinus
Western Europe
emerging
Antibiotics
Lyme disease
Ixodes ricinus
Europe, N. Africa
common,
emerging
Prevention of tick
bites, antibiotics
West Nile
Culex pipiens et al.
Southern/Eastern
Europe
rare (1996, 1999,
2003, 2004, 2010,
2011)
No (vaccine
development in
progress)
Ockelbo disease
Culicidae spp.
Scandinavia,
France
common
???
Toscana virus
meningitis
Sandfly
(Phlebotomus
spp.)
Mediterranean
countries
???
Avoid sandfly
bites
Dengue
Aedes albopictus
Tropics
accidental
introductions
Difficult once
introduced
Chikungunya
Aedes albopictus
(sub)tropics
accidental
introductions
Difficult once
introduced
Babesiosis
Dermacentor
reticulatus
Southern Europe,
Africa
common
Antibiotics
MALARIA
sexual stages of malaria parasites in red blood cells
Malaria risk
Malaria in the Netherlands
Disease
outbreak
Summer
Spring
Autumn
Anopheles atroparvus:
3 generations per year,
overwintering as adult
Winter
Malaria
infection
Malaria in Wormerveer
1902 - 1920
A – Malaria house
B – Infected mosquito
C – Heavily infected house
Nikolaas Swellengrebel
1944: Introduction of DDT
Malaria 2014
Medicines and
bed nets
Impact of bed nets: estimated number of fever cases
seen at public health facilities in Africa in 2010
Source: WHO 2011
Estimated trends in malaria incidence rate and
mortality rate , 2000-2015
Source: WHO 2014
Emerging vector-borne diseases
Species
Disease
Invaded region
When?
Asian tiger mosquito
Chikungunya
Italy
France
Culicoides spp.
Bluetongue
North Europe
2006
Culicoides spp.
Schmallenberg
N.W. Europe
2011
Dermacentor
reticulatus
Babesiosis
North-Europe
????
Culex pipiens
West Nile virus
North America
Europe
1999
2010-2014
Asian tiger mosquito
Dengue
Americas
Europe
1986
2010-2014
Various mosquito spp.
Usutu virus
Europe
2007 & 2010,
2014
2000???
Recent example: Q-fever 2007-2010
Q-fever
The Netherlands
in 2009 (source: RIVM)
West Nile virus USA
1999-2014
1999
2014
Source: CDC 2015
Human cases of West Nile virus, USA – 1999 - 2014
West Nile virus
transmission
Culex pipiens pipiens
West Nile virus
outbreaks in Europe
2004
WNV
WNV
WNV
WNV
2010-2014
WNV
WNV
Aedes albopictus:
dengue vector in Europe
2005
2004
2014
2010
2004
2007
1988
2010: Chikungunya &
2007: Chikungunya
dengue fever
Distribution of Aedes
albopictus in Europe
2014
Lyme disease
Increase of Lyme disease in The Netherlands - 1994-2009
EM per
100.000
inhabitants
1994
2001
2005
200000
prognosis
175000
150000
125000
2009
100000
100000
92,639 tick bites
2
R = 0.9948
75000
75000
EM
50000
50000
Bites
2
R = 0.9889
25000
25000
0
22,020 patients with
erythema migrans
0
1994
2000
2010
2020
jul-11
mei-11
mrt-11
jan-11
35
30
25
10.0
20
15
10
1.0
5
0
0.1
Mean no. of nymphs per 200 sqm
% infected
nov-10
sep-10
jul-10
mei-10
mrt-10
jan-10
nov-09
sep-09
jul-09
mei-09
mrt-09
jan-09
nov-08
sep-08
jul-08
mei-08
mrt-08
jan-08
nov-07
sep-07
jul-07
mei-07
mrt-07
jan-07
nov-06
sep-06
jul-06
Percentage of ticks with Borrelia infections
Seasonal variation in tick densities and Borrelia
infections in The Netherlands
mean no. nymphs/site
100.0
Diseases transmitted by Ixodes ricinus
• Tick-borne encephalitis (TBE)
• Borrelia spp.
• Rickettsia helvetica
• Anaplasma spp.
• Babesia spp.
• Bartonella spp.
Geographic distribution of Ixodes ricinus complex
Geographic distribution of tick-borne encephalitis
ECDC 2012
Upper temperature for developmentof Ixodes scapularis in
Canada (source: Int J Parasitol 2006;36: 63–70)
Vectorborne diseases in
Europe
Eradicated:
Pest, Typhus, Yellow
fever, Malaria, Dengue
Present:
TBE, Leishmaniasis,
Ockelbo disease,
Theileria, Babesia
(cattle), Onchocerca
(cattle)
New:
West Nile virus,
dengue, Chikungunya,
Usutu, Bluetongue,
African horse sickness
Possible:
Emerging:
Lyme borreliosis,
Anaplasma, Rickettsia,
Tosca virus
CCH fever, Babesia,
Bartonella, Rift Valley
Fever
Emerging infectious diseases (Nature, 2004)
2006
Bluetongue virus
20142007
Chikungunya
2007fever
Chikungunya
2010
Leishmaniasis
Dengue
2005
Chikungunya fever
Rising global
temperatures
favourable for
vectors and
parasites /
pathogens
Source: IPCC 2014
Conclusions (1)
− Vector-borne diseases continue to remain a health risk for
travelers;
− Vector-borne diseases increase globally;
Reasons: trade, transport, travel, climate change
− VBDs are rapidly becoming a relatively high risk for travelers in
temperate climate zones;
− Monitoring is poorly organized;
− Preventive or management strategies in Europe are inadequate;
− Increasing poverty in least developed countries is obstacle to
lasting solution for vector-borne diseases;
Conclusions (2)
− Some vector-borne diseases are strongly climate restricted
(dengue, leishmaniasis, malaria);
− Higher temperatures favour arthropod vectors;
− Higher temperatues favorable for pathogen development in
the vector (e.g. tick-borne encephalitis; Chikungunya;
dengue; Rift Valley fever; West Nile virus)
− Development of risk models required;
Thank you
Further info: WUR\ENTO\UK.COM