Training for health professionals
Module – vector borne diseases
Introduction
• The incidence of vector-borne diseases
(VBD) in Europe is much greater than is
generally recognized
• As a result, diagnosis and treatment are
often delayed
• Health authorities often fail to allocate
funding for the surveillance and control
2
VBD & climate change in Europe
Tick-borne
Mosquito-borne Other insect-borne
Lyme disease
Chikungunya / Dengue* Leishmaniasis
Tick-borne encephalitis Malaria*
Chandipura virus
Human ehrlichiosis
West Nile virus
Sicilian virus
Tularaemia
Tularaemia
Tularaemia
Crimean-Congo*
Yellow fever*
Toscana virus
Sindbis viurs
Tahyna virus
* This disease is currently not present in Europe
3
Module vector-borne diseases
Training topics
• Tick borne diseases
• West Nile fever (mosquito borne)
• Dengue fever (mosquito borne)
• Chikungunya fever (mosquito borne)
• Leishmaniasis (sandfly borne)
4
Outline training
•
•
•
•
Objective
Definitions
Effect climate change on VBD
Specific information for each VBD (top-5)
–
–
–
–
•
Health effects
Current situation
Future situation
Actions needed
Summary
5
Training objective
• To learn how to be prepared for changes
in public health due to climate change
• Take home message
– Health impact
– Mitigation and adaptation
– Preventive measures on individual &
community level
6
Definitions [1]
• Mitigation = reducing the severity of
climate change (reducing greenhouse gas
concentrations)
• Adaptation = preparing for change
(adjusting our systems to reduce harm
from climate effects)
7
Definitions [2]
• Vector-borne disease (VBD) = an illness
caused by an infectious microorganism
(pathogen) that is transmitted to people by
a vector, usually arthropods
• Arthropod = an invertebrate animal
having an exoskeleton (e.g. insects or
arachnids)
8
Definitions [3]
• Types
Types of
of VBD
VBD transmission
transmission
– Anthroponotic infections
• Mosquitoes (Malaria), Ticks (Lyme
(Lyme disease)
disease)
– Zoonotic infections
• Rodents (plague), Birds (Q-fever)
Humans
Animals
Vector
Vector
Vector
Vector
Humans
Animals
Humans
9
Definitions [4]
• Common (arthropod) vectors
– Ticks
– Mosquitoes
– Sandflies
10
VBD & climate change
• Climate change will affect the distribution
of VBD in three ways:
– directly, by the effect on virus/parasite
development and vector competence
– indirectly, by the effect on the range and
abundance of the species that act as vectors
– indirectly, through socio-economic changes
that affect the amount of human contact with
the transmission cycles
11
VBD & climate change
• Most important climate factors
– Temperature
– Precipitation
12
Temperature effects
• Vector
– Survival decrease/increase depending on the
species
– Changes in rate of vector population growth
– Changes in the susceptibility of vectors to some
pathogens
– Changes in feeding rate and host contact
13
Temperature effects
• Example
– Summer: more days with high(er) temperature
• Longer lifespan
• Longer reproduction period
• Longer activity period
– Winter: less days with low temperature
• Benefits overwintering
• Shorter overwintering
14
Temperature effects
• Pathogen
– Decreased extrinsic incubation period of
pathogen in vector at higher temperatures
– Changes in the transmission season
– Changes in geographical distribution
– Decreased viral replication
15
Precipitation effects
• Vector
– Survival: increased rain may increase larval
habitat
– Excess rain can eliminate habitat by flooding
– Low rainfall can create habitat as rivers dry into
pools (dry season mosquitoes)
– Decreased rain can increase containerbreeding mosquitoes by forcing increased water
storage
16
Precipitation effects
• Vector (continued)
– Heavy rainfall events can synchronize vector
host-seeking and virus transmission
– Increased humidity increases vector survival
and vice-versa
• Pathogen
– Few direct effects but some data on humidity
effects on parasite development
17
Summary effects climate change
• Climate change has the potential to
– Increase range or abundance of animal
reservoirs and/or arthropod vectors
– Enhance transmission
– Increase importation of vectors or pathogens
18
Module – vector borne diseases
Tick-borne diseases
Tick-borne diseases
• Ticks are a distinct group of mites
• As blood feeding parasites, ticks are able
to transmit a wide variety of pathogens
• This may cause tick-borne infections and
diseases affecting
– Animals
– Humans
20
Tick-borne diseases
• Stages of the tick life-cycle
1. Egg
2. Larva
3. Nymph
4. Adult
• Ticks can transmit disease during the
three last life-cycle stages.
21
Tick-borne diseases
• Tick-borne diseases to be aware of in
Europe include:
– Lyme borreliosis (LB)
– Tick-borne encephalitis (TBE)
– Tick-borne relapsing fever (TBRF)
– Crimean-Congo haemorrhagic fever (CCHF)
22
Current situation - ticks
• In Europe, 90% to 95% of all tick bite
incidences in humans are caused by
– Ixodes ricinus
– Ixodes persulcatus
23
Current situation
• Yearly number of cases in Europe
– Lyme borreliosis: ~ 85,000
– Tick-borne encephalitis: ~5,000-8,000
– Tick-borne relapsing fever: rare
– Crimean-Congo haemorrhagic fever:
endemic in Bulgaria since 1950 (‘50-’08:
1,568 cases; 17% mortality), recently new
area’s
24
Climate & ticks
• Climate suitability for the tick I. ricinus
- Stable trends
25
Climate & ticks
• Climate suitability for the tick I. ricinus
- Random trends
26
Future situation ticks
• Climate change
– Distribution to higher latitudes and altitudes
• Climate conditions
– Temperature
• During summer: temperature > 5-8 ºC
• During winter: high enough to continue life cycle
– Humidity
• Sufficient to prevent both eggs and ticks from
drying out
27
Tick borne disease
- Lyme borreliosis -
Lyme borreliosis (LB)
• Lyme borreliosis = a bacterial infection
caused by member of the genus Borrelia
• Vector borne
– Bite by infected tick (B. burgdorferi)
– Tick species I. ricinus (Europe)
• Bacteria resevoir host
– many species of small mammals
– ground-feeding birds
29
LB – health symptoms
• Health symptoms
– Local skin rash (80-90% of cases)
– Neuroborreliosis (main complication, 10%)
– Meningoencephalitis (less common)
• Risk groups
– All persons exposed to risk of tick bites are at
risk of becoming infected.
30
LB – geographical distribution
• In Europe, the mean prevalence of
B. burgdorferi infected ticks is about 12%
• Regions with highest tick infection rates
are located in central Europe
– Austria, Czech Republic, Southern Germany,
Switzerland, Slovakia and Slovenia
– Nymphs > 10%, adults > 20%
31
LB - available warning systems
• Lyme borreliosis is not a notifiable disease
in the European Union (in contrast to USA)
• No licensed vaccine is currently available
• Main methods of preventing infection are
avoiding tick bites and early removal of
attached ticks.
32
Tick borne disease
- Tick-borne encephalitis -
Tick-borne encephalitis (TBE)
• Tick-borne encephalitis = disease
caused by a virus of the Flaviviridae family
• Vector borne
– Bite by infected tick
– Tick species I. ricinus (Europe)
• Virus reservoir host
– Mainly small rodents
– Also insectivores and carnivores
34
TBE – transmission mode
• Other transmission modes
– By consumption of infected unpasteurised
dairy products.
– Not directly from human to human, apart from
mother to the foetus
– Laboratory accidents (needle-stick injuries or
aerosol infection)
35
TBE – health symptoms
• Health symptoms
– Two third of human TBE virus infections is
asymptomatic
– Clinical cases
• 1st fase: nonspecific symptoms (fever, fatigue etc.)
• 2nd fase: central nervous system affected
• Several TBE virus infection subtypes
– European, Far Eastern, Siberian
36
TBE – health symptoms
• European subtype
– Milder compared to other subtypes
– 20-30% of patients experiencing the 2nd phase
– Severe neurological sequelae in 10% of
patients
– Mortality rate 0.5-2%
• Risk groups
– All persons exposed to risk of tick bites are at
risk of becoming infected.
37
TBE – geographical distribution
• TBE has become a growing public health
challenge in Europe and other parts of the
world
• The number of human cases of TBE in all
endemic regions of Europe has increased
by almost 400% in the last 30 years
• The risk areas have spread and new foci
have been discovered
38
TBE – geographical distribution
• TBE is present in
– Southern Scandinavia
– Central and Eastern Europe
• Risk of contracting the disease from a
single bite is 1 in 600 in endemic regions
39
TBE - available warning systems
• Notifiable disease in 16 European
countries, including
– 13 European Union (EU) Member States
– 3 non-EU Member States
• A vaccine is available
• People at high risk of an infection are
vaccinated in Sweden and other countries
40
Tick borne disease
- Tick-borne relapsing fever -
Tick-borne relapsing fever (TBRF)
• TBRF = a bacterial infection caused by
member of the genus Borrelia
• Vector borne
– Bite by infected tick
– Tick species Ornithodoros
• Bacteria reservoir host
– Ticks
– Small mammals/birds/reptiles/bats
42
TBRF – health symptoms
• Health symptoms
– High fever (> 39-40°C)
– Other symptoms include
• Intensive asthenia, headache, arthralgia, myalgia,
neck stiffness, stomach ache and nausea.
• Splenomegaly and hepatomegaly, usually
associated with jaundice, and elevated pulse and
blood pressure are common.
• Following the initial fever episode further
relapses will occur
43
TBRF – risk groups
• Two epidemiological types of TBRF have
been described:
– Sporadic TBRF
• Observed in ‘at-risk’ groups like soldiers, hunters,
campers, field workers or travellers
• Developed countries
– Endemic TBRF
• Caused by rare but regular contact with infected
ticks directly living in rural human dwellings
• Developing countries
44
TBRF – geographical distribution
• The greatest endemic risk in Europe lies in
the Iberian Peninsula, particularly in the
Mediterranean part, and in Asia Minor
• Reports of imported TBRF cases have
come from the UK, Belgium and France
• The number of cases is underestimated
because most infections are benign, and
no diagnosis is made
45
TBRF – available warning systems
• TBRF is not a notifiable disease in the
European Union
• No licensed vaccine is currently available
• Main methods of preventing infection are:
– Avoiding tick-infested areas
– Avoiding tick bites
46
TBRF – available warning systems
• Main methods of preventing infection
(continued)
– Removal or decreasing tick vectors and
natural vertebrate reservoirs from buildings
• Chemical treatments
• Natural predators like domestic cats
• Limiting rodent-friendly environments inside and
around buildings
47
Tick borne disease
- Crimean-Congo
haemorrhagic fever -
Crimean-Congo haemorrhagic
fever (CCHF)
• CCHF = a viral infection caused by the
genus Nairovirus, Bunyaviridae family
• Vector borne
– Bite by infected tick (nymph or adult)
– Tick species Hyalomma
• Virus resevoir host
– Immature ticks: hares and hedgehogs
– Mature ticks: domestic animals (cattle etc.)
49
CCHF – transmission mode
• Other transmission mode:
– direct contact with infected blood or body
fluids
– contaminated medical equipment or supply
50
CCHF- health symptoms
• Health symptoms
– A sudden onset of febrile illness with
headache, myalgia, backache and joint pain,
abdominal pain and vomiting.
– Frequently followed by:
• Haemorrhagic manifestations
• Necrotic hepatitis may occur
• Large ecchymosis and uncontrolled bleeding from
venipuncture sites are common features.
51
CCHF – health symptoms
• Mortality rate of CCHF is ~ 30% with death
occuring in the 2nd week of illness
• Risk groups
– Farmers, veterinarians and abattoir workers in
endemic areas
– Healthcare workers (when nursing CCHF
patients)
– Outdoor activities in endemic areas
52
CCHF - geographic distribution
• The geographic range of CCHF virus is
known to be the most extensive of the tick
borne viruses important to human health.
• In Europe, cases have been reported from
Albania, Bulgaria, Kosovo, Turkey and the
former Soviet Union
• In Greece, the first human case of CCHF
infection was reported 2008
53
CCHF – available warning systems
• CCHF is not a notifiable disease on
European Union level
• No validated specific antiviral therapy for
CCHF.
• Main methods of preventing infection are:
– Avoiding tick-infested areas
– Avoiding tick bites
54
CCHF – available warning systems
• Main methods of preventing infection
(continued)
– Removal or decreasing tick vectors and
natural vertebrate reservoirs from buildings
• Chemical treatments
• Natural predators like domestic cats
• Limiting rodent-friendly environments inside and
around buildings
55
Summary – tick borne diseases
• Tick borne disease & climate change
– Distribution to higher latitudes and altitudes
• Tick-borne diseases to be aware of in
Europe
– Lyme borreliosis
– Tick-borne encephalitis
– Tick-borne relapsing fever
– Crimean-Congo haemorrhagic fever
56
What actions are needed?
• Public health surveillance at the European
level (compulsory notification system in all
countries)
• Educate the public on interventions
against ticks
• Further research on tick distribution
57
Module – vector borne diseases
Mosquitoes borne diseases
West Nile – Dengue - Chikungunya
Mosquitoes-borne
• This training
– Culex mosquitoes  West Nile fever
– Aedes mosquitoes  Dengue fever
– Asian Tiger mosquitoes Chikungunya fever
(Aedes albopictus)
59
Mosquito borne disease
- West Nile fever -
West Nile – mosquito borne
• West Nile fever = disease caused by a
virus of the Flaviviridae family (West Nile
virus, WNV)
• Vector borne
– Bites of infected mosquitoes
– Culex mosquitoes species
• Virus reservoir host
– Birds
61
West Nile – transmission mode
– Direct transmission between animals has been
seen experimentally
– Infected humans and horses do not seem to
spread the virus to other mammals
– Person-to-person transmission has not been
reported
– In rare cases, the virus has been spread by
blood transfusions, organ transplants, and
transplacental transmission
62
West Nile – health effects
• Asymptomatic infections (~80%)
• Clinical symptoms
– Mild
• Flu-like symptoms, including fever, headache and
body aches.
• Most uncomplicated infections resolve in 3-6 days
– Severe clinical cases
• Neuro-invasive disease: there may be signs of
encephalitis, meningo-encephalitis or meningitis.
63
West Nile – health effects
• An estimated 1 out of 140 - 320 infections
results in meningitis or encephalitis.
• The case fatality rate in patients with
neuro-invasive illness ranges from 4% to
14%; it can reach 15–29% in patients over
70 years old.
• Concurrent disorders such as diabetes or
immunosuppression increases the risk of
death.
64
West Nile – mosquito borne
• Culex species (Cx. spp.)
– Large number of spp. world wide (> 700)
– About 20 spp. are present in Europe
– Infection and transmission rates are variable
• Example: mosquitoes from the Rhone delta, France
Cx. modestus
Infection rate:
89.2%
Transmission rate:
54.5%
65
Cx. pipiens
38.5%
15.8%
Current situation
• Worldwide distribution Cx. mosquitoes
– Distributed worldwide
– They can be found in tropical and temperate
climate zones on all continents except
Antarctica
• Europe distribution Cx. mosquitoes
– Wetland areas of high biodiversity
– Cx. pipiens spp. urban/city dweller
66
Current distribution - mosquito
Distribution of the Culex pipiens complex and its sibling species
Source: Smith 2004
67
West Nile – health impact
• West Nile Fever worldwide
– West Nile Fever is distributed worldwide
– Outbreaks may occur in humans, birds, and horses in
Africa, Europe, Russia, India, and Australia
• West Nile Fever Europe
– Erratic and spatially and temporally limited
phenomena
– Occurring quite unpredictably, even if all conditions
appear to be present in a definite place
68
West Nile – health impact
• Risk groups
– People over 50 years old are at higher risk of
developing severe neurological disease and
should take special care to avoid mosquito
bites.
69
Current distribution West Nile
70
Available warning systems
Country Control measures
Greece
• Enhanced surveillance for human cases
• Adulticiding (ultra-low volume spraying) of mosquitoes in villages
with human cases
• Public education campaigns for personal protection
• Education and guidance to school teachers and health care
personnel
Romania
• Seasonal surveillance for human cases
• Blood safety measures
Turkey
• Improved surveillance (active and passive) for human cases
• Inclusion of WNV as a notifiable disease for 2011 season
71
Available warning systems
• West Nile fever is a notifiable disease in
the European Union
• The ECDC is responsible for the
surveillance of infectious diseases in the
European Union.
72
Future situation
• Current situation Europe
– Autochthonous WNV infections in several
countries during the transmission season
• Future situation & climate change
– The dynamics of transmission of WNV are
complex  difficult to predict the situation for
Europe in the coming years
– Data indicate that the epidemiology of WNV in
Europe is changing
73
What actions are needed? [1]
• Development of a vaccine
• Need for integrated multidisciplinary
surveillance systems and response plans
• Raising the awareness of clinicians and
veterinarians of the clinical presentation of
WNV disease in humans and horses
– Particularly during the mosquito season from
June to October
– Primarily in areas considered as at major risk
surrounding (irrigated areas and river deltas)
74
What actions are needed? [2]
• More research to
– Suitable habitats for birds that would increase
the bird-mosquito-human interface
– Competent vector species
– Establish limits around WNV affected areas
– Identify potential new at-risk areas
– Study the cycle of transmission and the
maintenance of WNV in the environment over
the years
75
Mosquito borne disease
- Chikungunya fever - Dengue fever -
Chikungunya & Dengue
• Chikungunya fever = disease caused by
a virus of the Togaviridae family (CHIKV)
• Dengue fever = disease caused by a virus
of the Flaviviridae family (dengue virus;
DENV)
• Vector borne
– Transmitted from human to human by bites of
infected mosquitoes
77
Chikungunya & Dengue
• Vector borne (continued)
– Aedes mosquitoes species (both CHIKV and
DENV)
• Virus reservoir host
– Humans
78
Transmission mode
• Bites of infected mosquitoes
• Direct contact with infected blood or body
fluids
• Contaminated medical equipment or
supply
• Can be transmitted from mother to child
79
Climate change & Aedes
mosquitoes
- Chikungunya fever - Dengue fever -
Chikungunya & Dengue
• Aedes mosquito species
– Ae. aegypti
• Diurnal biting habits
• Once endemic in Europe, disappeared after WWII
– Ae. albopictus (Asian tiger mosquito)
• Not host-specific
• Present in southern Europe
81
Albopictus
Aegypti
Current situation
• Worldwide distribution Aedes mosquitoes
– Climate conditions
• Overwintering conditions: 0°C January isotherm
with ≥ 500 mm annual rainfall
• Development: monthly mean temperature ≥ 10°C
• Transmission: monthly mean temperature ≥ 20°C
– Risk zones Chikungunya/Dengue fever
• Originally, Africa, Southeast Asia, Indian
subcontinent and islands in the Indian Ocean
• Increasing presence of Aedes mosquitoes in
Southern Europe  new risk zone?
82
Current distribution - mosquito
Ae. aegypti
Ae. albopictus
83
Future situation – minimum impact
Year
2030
Year
2030
Climate change & long term impact on
Ae. Albopictus distribution
84
Future situation – maximum impact
Year
2030
Year
2030
Climate change & long term impact on
Ae. Albopictus distribution
85
Future situation
• Maps show the risk of establishment of Aedes
albopictus
• The maps do not report the risk of transmitting
exotic viruses, nor can one extrapolate from them
to assess any such risk
• Analysing this risk would require a significant
number of additional datasets, e.g. vector
capacity in the given eco-climatic settings which
are currently not available
86
Mosquito borne disease
- Chikungunya -
Chikungunya – health effects
• Clinical symptoms
– Incubation time of 4-7 days (range 1-12)
– Sudden onset of high fever (>38.5°C)
– Other (flu-like) symptoms:
• Headache, backpain, myalgia, arthralgia, rash
 Similar to Dengue fever
• Treatment
– Symptoms generally resolve within 7-10 days
– No vaccine or medication currently available
88
Chikungunya – health effects
• Possible complications
– Gastro-intestinal complications, cardiovascular decompensation or meningoencephalitis
– Fatalities have been reported mainly in aged
patients or where the patient’s immune
system was weakened by underlying
conditions
89
Chikungunya – health impact
• World wide
– ‘52: Tanzania
– ‘60s: Southeast Asia: India ~ 1.39 million cases
– ‘80s: Small outbreaks: Thailand < 12,000 cases
– ‘01-’07: Major outbreaks islands Indian Ocean
(1/3 of population) and India ~ 1.42 million cases
• Europe
– ‘07: outbreak in Italy  247 cases
90
Chikungunya – health impact
• Risk groups
– There are no particular risk groups: anyone
exposed to the infected vector may become
infected with the virus
• Vulnerable population for severe illness
– Pregnant women
– Children under 12 years old
– People with immune disorders or server
chronic illnesses
91
Current distribution – Chikungunya
92
Available warning systems
• Chikungunya is not a notifiable disease in
most of the European countries.
• There is no commercial chikungunya
vaccine
• Prevention of chikungunya is currently
based on individual protection against
mosquito bites
93
Mosquito borne disease
- Dengue fever-
Dengue – health effects
• Asymptomatic infections (40-80%)
• Clinical symptoms
– Mild fever
– “Classic” dengue fever
• Server flu-like symptoms: high fever, severe
headache, pain behind the eyes, muscle and joint
pains and rash
– Dengue haemorrhagic fever / Dengue shock
• <5 % of all cases, mostly children and adolescents
• Increase of vascular permeability that can lead to
life-threatening hypovolemic shock
95
Dengue – health impact
• World wide
– 2.5 billion people (two fifths of the world's
population) are now at risk from dengue
– WHO estimates there may be 50 million
dengue infections every year
• Europe
– Last endemic was in 1927-78 in Greece
– However, imported cases frequently reported
(travellers that have visited endemic areas)
96
Dengue – health impact
• Risk groups
– There are no particular risk groups: anyone
exposed to the infected vector may become
infected with the virus
• Since there are four virus serotypes, it is
possible to get dengue multiple times
within a lifetime
97
Current distribution - Dengue
98
Available warning systems
• Dengue is not a notifiable disease on
European Union level
• There is no dengue vaccine, but this is an
active field of research
• Prevention of dengue is currently based
on individual protection against mosquito
bites
99
Future situation
- Chikungunya fever - Dengue fever -
Future situation
• Current situation Europe
– Mosquito biting activity is highest in midafternoon.
– Incidental, travellers that visited endemic areas
• Future situation & climate change
– At present, no good prediction models
available
101
What actions are needed? [1]
• Short term
– Providing information to all people traveling from the
affected areas with high disease incidence
– Providing dengue/chikungunya virus fact sheets to
physicians, as returning travelers may present with
the disease,
– Reminding medical staff of the need to follow
universally accepted precautions when handling
samples from all patients
– Advising European Union member states on blood
donation policies
– Assessing the capability and capacity of laboratories
in Europe to diagnose dengue/chikungunya fever
102
What actions are needed? [2]
• Long term
– Further studies and documentation of vector
competence and capacity of Ae. albopictus would be
useful in areas in Europe where these vectors are
known to be present.
– Areas at risk of vector establishment need to be
identified and regularly monitored, and vector
surveillance implemented or strengthened in these
areas.
– Measures to prevent the introduction of Ae. albopictus
through the used tyre trade and plants transported in
water (e.g. Dracaena species) should be considered.
103
Summary – mosquito borne [1]
• Aedes species (dengue and chikungunya virus)
– It can be concluded that the temperate strains of
Aedes albopictus are here to stay — and that they
will spread (Southern Europe)
– New Aedes populations may become established in
other parts of Europe
• Culex species (West Nile virus)
– Autochthonous transmission of West Nile fever in
several European countries
– Data indicate that the epidemiology of WNV in
Europe is changing
104
Summary – mosquito borne [2]
• Actions
– Surveillance of the introduction and spread of this
vector, in particular in areas at risk, is important in
order to be prepared for the mosquito’s role in the
transmission of diseases
– Education of public (risk areas and travelers) and
health professionals
• Preventive measures
• Health effects
• Treatment
– Advising European Union member states on blood
donation policies
105
Module – vector borne diseases
Leishmaniasis – sandfly borne
Leishmaniasis – sandfly borne
• Leishmaniasis = disease caused by
Leishmaniasis parasite
• Vector borne
– zoonotic or anthroponotic
– usually by the bite of a phlebotomine sandfly
species
• Parasite reservoir hosts
– Wild animals (fox, rodents, wolves etc.)
– Domestic animals (dogs)
107
Transmission mode
• Bite by an infected sandfly
• Can be transmitted from mother to child
• Contaminated medical equipment or
supply (shared syringes)
108
Leishmaniasis – health effects
• Asymptomatic leishmania infections
• Forms of leishmaniasis
– CL: Cutaneous (most common)
– ML: Mucocutaneous
– VL: Visceral (most severe, affecting organs)
– Canine leishmaniasis (dogs)
109
Leishmaniasis – sandfly borne
• 500 phlebotomine species, but only about
30 transmit leishmaniasis
• Only the female sandfly transmits the
parasites
• 8 medically important in Europe
110
Current situation
• Worldwide distribution of parasite &
sandflies
– Areas that have at least one month with a
mean temperature of 20°C
• European distribution of parasite &
sandflies
– South of latitude 45oN and less than 800 m
above sea level
– Recent data suggest that the area has been
expanded
111
Current distribution – sandfly
P. papatasi
P. perfiliewi
P. ariasi
P. neglectus/syriacus
112
Current distribution – sandfly
P. tobbi
P. perniciosus
P. sergenti
P. similis
113
Leishmaniasis – health impact
• World wide
– An estimated 12 million people are infected
– 2 million estimated new cases/year
• Europe
– Incidence of leishmaniasis in humans is
relatively low (0.02- 0.49/100,000)
– 700 estimated new cases/year for Southern
European countries (3,950 if Turkey is
included)
114
Leishmaniasis – health impact
• Risk groups leishmania infections
– There are no specific risk groups for
leishmania infections
• Risk groups leishmaniasis
– HIV-positive people (visceral leishmaniasis)
– Intravenous drug users who share syringes
115
Current distribution – Leishmaniasis
116
Current distribution – Leishmaniasis
Source: Dujardin 2008
117
Available warning systems
• Compulsory notification system
– Portugal: compulsory for VL
– Spain: compulsory for VL in 12/17
autonomous communities
– Greece: compulsory for VL and CL
– Cyprus: compulsory for VL and CL
– Turkey: compulsory for VL and CL
118
Future situation
• Current situation Europe
– Sandfly biting activity is strongly seasonal, restricted to
summer months in most areas
– Southern Europe, below 800m above sea level
• Future situation & climate change
– Prolonged activity periods and shorter diapause
periods (overwintering)
– Extend northwards and into higher altitudes
– At present, no good prediction models available
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What actions are needed?
• Public health surveillance at the European
level (compulsory notification system in all
countries)?
• Educate the public on interventions
against sandflies
• Further research
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What actions are needed?
• Interventions against sandflies
– Insect repellents such as DEET
– Insecticides
– Use of insecticide impregnated nets and bed
nets
– Dog: topical applications and deltamethrinimpregnated collars
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What actions are needed?
• Further research on
– Alternative modes of transmission
– Effective vaccine for human leishmaniasis
• immunisation strategy for Mediterranean
populations
– Effective vaccine for canine leishmaniasis
• to control the infections in vector reservoir dogs
– Better predictive modelling of disease
transmission
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Summary – sandfly borne [1]
• Currently, Leishmaniasis infected sandflies
are present in Southern Europe (max.
800m above sea level)
• Climate change may extend this risk area
northwards and into higher altitudes
• Actions
– Surveillance of the introduction and spread of
this vector
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Summary – sandfly borne [2]
• Actions (continued)
– Education of public (risk areas and travelers)
and health professionals
• Preventive measures
• Health effects
• Treatment
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Module – vector borne diseases
SUMMARY
Training objective
• To learn how to be prepared for changes
in public health due to climate change
• Take home message
– Health impact
– Mitigation and adaptation
– Preventive measures on individual &
community level
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Summary – module VBD [1]
• Health impact climate change
– Tick borne disease  highest tick infection
rates in central Europe  may spread to
northern areas
– Mosquito borne disease 
• West Nile virus  spatially and temporally limited.
However, autochthonous transmissions.
• Chikungunya  outbreak in Italy in 2007. In future,
Southern Europe may be at risk.
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Summary – module VBD [2]
• Health impact climate change (continued)
– Mosquito borne disease 
• Dengue  currently not present in Europe. In
future, Southern Europe may be at risk.
– Sandfly borne disease  Leishmaniasis is
endemic in Southern Europe. In future, risk
area may extend northwards and into higher
altitudes
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Summary – module VBD [3]
• Adaptation
– Surveillance of the introduction and spread of
the vector, in particular in areas at risk
– Providing information to all people traveling
from the affected areas with high disease
incidence
– Providing fact sheets to physicians
– Reminding medical staff of the need to follow
universally accepted precautions when
handling samples from all patients
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Summary – module VBD [4]
• Adaptation (continued)
– Advising European Union member states on
blood donation policies
– Assessing the capability and capacity of
laboratories in Europe to diagnose vector
borne disease
– Development of vaccines
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Summary – module VBD [5]
• Preventive measures on individual level
– Avoiding risk areas (if possible)
– When staying in affected areas
• Wear long-sleeved shirts and long trousers, and
trousers tucked into socks
• Use insect repellents such as DEET
• If possible, sleep under bed nets pre-treated with
insecticides
• If possible, set the air conditioning to a low
temperature at night
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Summary – module VBD [6]
– When staying in affected areas (continued)
• Good screens on windows and doors
• Remove tick within 24 hours (hard ticks)
132
Summary – module VBD [7]
• Preventive measures on community level
– Blood donation restrictions have to be
considered in areas where a vector borne
virus is circulating
– Limiting vector friendly environments (next
slides)
133
Summary – module VBD [8]
• Ticks
– Chemical treatment
– Natural predators like domestic cats
– Limiting rodent-friendly environments inside
and around buildings
– Acaricides may be useful on domestic
animals to control CCHF virus-infected ticks if
used 10–14 days prior to slaughter or to
export of animals from enzootic regions
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Summary – module VBD [9]
• Mosquitoes
– Insecticides
– Removal of breeding sites around buildings:
emptying stagnant water in and around the
houses on a weekly basis
• Limiting vector friendly environments sandflies
– Dog: topical applications and deltamethrin
impregnated collars
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More information
Websites
• www.climatetrap.eu
• www.ecdc.eu
• www.who.int/globalchange/en/
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