institute of parasitology (ipz) medical and vetsuisse...

19.01.2011

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Durch Arthropoden übertragene Pathogenein der Schweiz:

neue Arthropoden, neue Pathogene, neue Liaisons (aber immer noch das selbe alte Land)

Alexander MathisVektor Entomologie Gruppe

Institut für Parasitologie Vetsuisse und Medizinische Fakultät

Institute of Parasitology (IPZ)Medical and Vetsuisse Faculty

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Arthropods at IPZ:

• Research projects (e.g. sheep scab, Babesia spp.)

• Teaching (Veterinary and Medical Faculty UZH)

• Identification (diagnostic unit)

• 2006: Report on veterinary entomology in Switzerland (FVO) (Authors: Mathis and Deplazes)

Conclusion: ‚knowhow is scant and scattered‘

• Since 2007: National reference laboratory for epizootic-associated vectors (FVO)

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Vector entomology in Switzerland

2006: „Knowhow is scant and scattered“

2007: National Reference Laboratory for Epizootic-Associated Vectors: IPZ University of Zurich (FVO)

2009: Centre National de Référence pour les Maladies Transmises par les Tiques, Université de Neuchâtel (FOPH)(Dr. O. Péter)

2010: Start-up conference ‚Swiss Vector Entomology Group‘

Initiative: P. Müller, C. Lengeler (Swiss TPHI); F. Schaffner, A. Mathis (IPZ UZH); Christoph Hatz (IFSPM UZH/STI);Peter Lüthy (ETHZ)

Invite/involve all potentially interested Swiss research groups

Institute of Parasitology (IPZ)Medical and Vetsuisse Faculty

Vector Entomology Group

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Alexander Mathis, Prof. Dr. sc nat ETH

Francis Schaffner, Dr., PhD, senior research associate, entomologist

Christian Kaufmann, Dr., PhD, postdoc, entomologist

Irene Steinmann, veterinarian, doctoral student Claudia Tritschler, master student (veterinarian)Alexandra Blaser, maser student (veterinarian)Stefanie Wagner, master student (biologist)

Jeannine Hauri, technician

Funding FVO; Forschungskredit/Investitionskredit UZH, EU (EDENext) (current grant proposals: SNF, UZH)

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Arthropod-borne pathogens in Switzerland: new arthropods, new pathogens, new liaisons

(but the same old country)

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1) Big surprise: subtropical Babesia bigemina in fatal disease outbreak in cattle

2) Spillover of a cattle parasite to chamois?

3) The ‚oriental eyeworm‘ on the way: exploiting an extraordinary insect vector

4) Asian invasion: emergence of Aedes japonicus

in Central Europe

5) Indigenous midges as vectors of the African bluetongue virus

1) Big surprise: Babesia bigemina in fatal disease outbreak in a cattle herd in Chur

• cattle herd (›300 animals) of an animal trader

• 29 animals died

• clincal signs: fever, anorexia, agalactia, dullness, anaemia and occasionally hemoglobinuria

• Anaplasma marginale, A. phagocytophilum, Babesia sp. and Theileria sp. (tick-borne pathogens)

• all animals culled (ruling by the FVO)Hofmann-Lehmann et al., JCM 42:3775-80, 2004

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Fatal disease outbreak in a cattle herd in Switzerland


Ectoparasites:

- few Ixodes ricinus

- massive infestation with sucking lice Haematopinus eurysternus

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Identification by PCR/sequencing:

Babesia bigemina

first identification in Central Europe

large Babesia sp.

B. bigemina: reports from Europe

CHUR

Mediterranean

Spain

Por

tuga

l

France

Germany

Austria

Great Britain

Chur

Tick vectors of B. bigemina: Boophilus spp., Rhipicephalus evertsi

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Genotyping of Babesia bigemina isolates

Isolates from Switzerland (Chur), Italy, Spain, Turkey, Kenya, Zimbabwe, Mexico

Genotyping at three loci– rDNA ITS2; rap1c; gp45

Swiss isolate: distinct from Italian isolates

clustering with a Spanish isolate (no isolatesfrom the Balkans available)

(Hilpertshauser et al., 2007)

Survey on the occurrence of Babesia spp. in Switzerland

• identification of Babesia spp. from clinical cases (n=13) in cattle in Switzerland (PCR/sequencing)

No B. bigemina (all B. divergens)

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Ticks (2017) collected from cattle

– morphological identification

99.2% Ixodes ricinus, D. marginatus, H. punctata

Boophilus spp., R. evertsi (known vector species of B. bigemina) not found

Dermacentor sp.Haemaphysalis sp.

Ixodes sp.(Hilpertshauser et al., 2006)


Ticks (2017) collected from cattle

– PCR-detection of Babesia spp. in collected ticks

4 Babesia spp. identified in 26/700 ticks, (B. divergens/capreoli, B. major, Babesia EU1, Babesia CH1)

no B. bigemina

Dermacentor sp.Haemaphysalis sp.

Ixodes sp.(Hilpertshauser et al., 2006)

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Big surprise: Babesia bigemina in fatal disease outbreak in a cattle herd in Chur

• B. bigemina and its tick vector species not established in Switzerland

• The way of introduction remains obscure

introduction of infected ticks (imported fodder)?

2) Spillover of a cattle parasite to chamois?

(in collaboration with Marie Pierre Ryser, Institute of Animal Pathology, BE)

Sources: Internet

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Spillover of a cattle parasite to chamois?

• adult chamois found dead in two regions from the Swiss alps

Gantrisch BE (2175 m)Tösstock ZH (1154 m)


• adult chamois found dead in two regions from the Swiss alps

• game wardens: increased mortality in recent years

• pathology: haemolytic anaemia

• blood smear:

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Tentative diagnosis: blood agent

• Anaplasma spp.: negative

• Babesia spp.: positiveSequencing (400 bp 18S rRNA gene):

99.6-100% identity with GenBank entries

B. divergens (many): cattle

B. capreoli (1): roe deer

B.divergens/capreoli-like organism

Babesia divergens in cattle in Switzerland

2004, IPZ

2005/06, IPZ

2002, IPB

2006/07, IPZ; B. divergens/capreoli-like in dead chamois

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Babesia divergens/capreoli-like in chamois

1) The cattle track (Tösstock area)

No indication for cattle infections with Babesia spp.

• Survey (local farmers, vets): – clinical disease not known in cattle

• Cattle (n=430) IFAT; PCR (Schmid et al., 2008)

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Babesia divergens/capreoli-like in chamois

1) The cattle track

No indication for cattle infections with Babesia spp.

• Survey (local farmers, vets): – clinical disease not known in cattle

• Cattle (n=430) IFAT; PCR (Schmid et al., 2008)

2) The roe deer track

Prevalence in healthy roe deer:

26% (12/46) (Hoby et al., 2008)

24.6% (55/223) (Michel et al., 2010)

Genotyping B. divergens/capreoli-like: rDNA locus

rDNA ITS ITS 1 ITS 2 28S

Cattle JUCattle GRRoe deer ZHRoe deer BEChamois ZH

Cattle, CH

Roe deer, east CHRoe deer, west CHChamois, east CH

(Schmid et al., 2008)

B. capreoli

B. divergens

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Elevation range of wild ungulates (48 chamois, 46 roe deer) from the Tösstock and Gantrisch area

(Hoby et al., 2009)

negative positive negative positiveBabesia capreoli Ixodes ricinus

B. capreoliroe deer 12/46; chamois 1/48

Elevation range of wild ungulates (48 chamois, 46 roe deer) from the Tösstock and Gantrisch area

(Hoby et al., 2009)

Spillover of B. capreoli from roe deer to chamois in overlapping habitat in the foothills of the Alps


Habitat range

Roe deer

Chamois

frequent occurrence of chamois and roe deer on pastures

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Risk for spread of B. capreoli to alpine chamois?

(Hoby et al., 2009)


Habitat range

Roe deer

Alpine chamois habitat1800-3000 m

Ticks

B. capreoli: Outlook

Very closely related (serology, genetics) with cattle

B. divergens, but distinct host specificity and

pathogenicity

• Determinants of pathogenicity

(metagenomics; proteomics; metabolomics)

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3) The ‚oriental eyeworm‘ on the way: exploiting an extraordinary insect vector

Thelazia callipaeda‚Oriental eyeworm‘Nematode

Phortica spp. (5 mm)

Fruit fliesDrosophilids

Zoophilic behaviourFeeding on lacrimal secretions

Distribution of Thelazia callipaeda‚Oriental eyeworm‘

China: 1910 (dog), 1917 (human)

Thailand, India, Indonesia, Taiwan, Japan, Korea

2008 human thelaziosis (Italy, France)

1989

2003

2007

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The ‚oriental eyeworm‘ is also a Swiss eyeworm

Thelazia-prevalences

dogs (6.2%)

cats (n=5)

foxes (11.1%)(black: shot foxes)

Malacrida et al. 2008

Retrospective analysis:First 2 cases in dogs in 2000

Cross-sectional studyCanton Ticino:

Extrapolation: total 1055 infected dogs in Ticino

Phortica drosophilid flies within and outside a recently identified endemic area of the eye worm (Thelazia callipaeda) in Switzerland

Catching methods

Netting around bait (2 h)

eye of dog bag filled with overripe fruit

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Catching methods

Evaluation of passive traps

1.5 l PET bottles, baited with overripe fruit

entry


Phortica catches (May-Nov.)

Site 1 (Gentilino): N=674

Site 2 (Bodio): N= 980

Site 4 (Airolo): N=1

Site 5 (Zürich): n=40Zurich

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Genetic analysis of Phortica flies from Switzerland

Dendrogramm of Phortica spp. from Ticino and Zurich based on partial mt coxI gene sequences:

Phortica from Ticino and Zurich genetically indistinguishable

Roggero et al. (2010)

Spread of Phortica-transmitted Thelazia eyeworms?

Southern Ticino (high abundance of Phortica)Yes

North of the alps (low abundance of Phortica)Occasionally

First case of autochthonous transmission of Thelazia callipaeda in a dog in Baden-Württemberg!

Genotype different from the one in Southern Europe.

(Magnis et al., 2010)

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4) Asian invasion: emergence of Aedes japonicus in Central Europe

Emergence of Ae. japonicus in Central Europe

• July 2008: complaints about insect nuisance (canton Aargau); mosquito specimen resembling Ae. albopictus (tiger mosquito)

• Same area from which Ae. albopictus was reported in 2007 based on photography of incomplete insect

Distribution of Ae. albopictus, January 2008

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Emergence of Ae. japonicus in Central Europe

• July 2008: complaints about insect nuisance (canton Aargau); mosquito specimen resembling Ae. albopictus (tiger mosquito)

• Same area from which Ae. albopictus was reported in 2007 based on photography of incomplete insect

• Morphology, mt COXI sequence: Aedes japonicus (first finding in Switzerland)

Ae. japonicus: diagnostic characters of adults

Black and white mosquito, usually large, similar to Ae. albopictus, but differs in ornamentation of:

- mesonotum- palpi extremity - fourth tarsomere

Ae. albopictus

Ae. japonicus

Cx. pipiens

Ae. albopictus Ae. japonicus

Workshop Bestimmungsübungen, Samstag(Francis Schaffner: Neues zu Culicidae)

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Ae. japonicus: diagnostic characters of adults

Ae. albopictus

Ae. japonicus

Cx. pipiens

Ae. albopictus Ae. japonicus

Tigermücke in Wohlen9. Sept. 2007

Aedes japonicus

‘Asian bush mosquito’

Aedes (Finlaya) japonicus (Theobald, 1901) (=Ochlerotatus japonicus sensu Reinert et al. 2004)

Breed in rock pools as well as in artificial container habitats

Eggs: resistant to desiccation, winter diapause

Native range: Japan, Korea, China

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Ae. japonicus – an invasive vector species

Transported by human activities, e.g. used tyre trade

Known as an invasive species

www.issg.org

Ae. japonicus – recent territorial expansion

• Intercepted in New Zealand (1993, 1998 & 1999) (Laird et al. 1994; Fonseca et al. 2001)

• First established outside its native range in the USA in 1998, spread to 22 states incl. Hawaii, and parts of Canada (Williges et al., 2008)

• Europe:

– France (Normandie), 2000: detected on a platform for imported used tyres (then eliminated) (Schaffner et al., 2003)

– Belgium, since 2002: established, but so far only on two storages of used tyres (Versteirt et al., 2009)

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Ae. japonicus – vector role

Vector role under natural conditions unknown

• Laboratory vector of several

arboviruses e.g. JEv, WNv

• WNv regularly detected in

field-caught Ae. japonicus

• Feeds on mammals and birds

(good bridge vector candidate)

WNv

Ae. japonicus in Central Europe: field investigations

Focus on larval collections in potential breeding sites

flower vases in cemeteries particularly useful

• Most of the checked cemeteries

(86.6%, n=134) provided 3 or

more vases containing water

• Vases generally positive when

the species is present (91.2 %, n=34)

• Cemeteries easily accessible

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Mosquito species collected in man-made breeding sites, Switzerland, 2008

Ae. geniculatus 9Ae. japonicus 160

An. maculipennis 5An. plumbeus 36

Cs. annulata 3Cs. longiareolata 3

Cx. pipiens, Cx. hortensis 501Cx. territans 1Cx. torrentium 3

617 / 3542 investigated breeding vessels with mosquito larvae

Distribution of Ae. japonicus in Central Europe 2008

Country Switzerland (Canton) Germany (Kreis) France (Dép.)

Administrative unit (NUTS3) AG BL BS BE LU SZ SO ZG ZH Lörrach Waldshut Haut-Rhin Total

Ae. japonicus present 29 2 0 0 1 0 1 0 3 0 2 0 38

Ae. japonicus absent 22 6 1 2 5 2 6 1 30 4 3 3 85

Total no 51 8 1 2 6 2 7 1 33 4 5 3 123

Tab.: Investigated municipalities per country and administrative unit level 3

Ae. japonicus in CH in area of approx. 1,400 sq km

present in bordering Germany (Baden-Württemberg)

Fig.: Positive and negative sites observed in the investigated area (CH, DE and FR),Aug. 14th to Nov. 6th, 2008

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Abundance of mosquito species

Vase index = percentage of cemetery vases with mosquito larvae

Vases All mosquitoes Ae. japonicus Cx. pipiens, Cx. hortensis

no total

no pos. mean index no pos. mean index no pos. mean index

Ae. japonicus present (n=33)

833 193 29.1 118 21.4 96 11.8*

Ae. japonicus absent (n=93)

2186 244 10.0 n.a. n.a. 231 9.4

Whole studied area 3019 437 15.0 118 5.6 327 10.0

Tab.: Occurrence of mosquitoes in vases in cemeteries pos. = mosquitoes present

* significantly lower index values compared to index values for Ae. japonicus (Friedman-test: P<0.01; post hoc test: p<0.05)

Ae. japonicus, if present, is more abundant in vases than the most common species Cx. pipiens

Aedes japonicus in Switzerland: a threat to native biodiversity?

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Country Switzerland G F

Administrative unit (NUTS3) AG BL BS BE LU NW SH SO SZ ZG ZH Lö Wh H-R Total

Ae. japonicus present 29+3 2+1 0 0 1+1 0 0 1+1 0 0 3+7 0 2 0 38+13

Ae. japonicus absent 21 7 1 2 7 2 1 6 5 2 26 4 3 3 91

Total no 53 10 1 2 9 2 1 8 5 2 36 4 5 3 142

Tab.: Investigated municipalities per country and administrative unit level 3, 2008-09

2009: 50 municipalities investigated

13 new positive

Territorial extension in all direction

Ae. japonicus in CH in area of approx. 2,500 sq km

Winterthur

Wädenswil

Pratteln

Lucerne

Egerkingen

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Schaffhausen

Schänis

Allschwil

Sarnen

Biel

Aedes japonicus: Summary and outlook

First finding of proliferation and spread of an invasive mosquito in Central Europe.

Invasive and vector potentials render this species a potential threat for animal and human health.

Need for further studies:

Dispersal/pattern of expansion, introduction site(s)

Vector capacity in the local environment (host preference, abundance, vector competence, e.g. West Nile virus)

Control

(Funding requested from national and international agencies)

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5) Indigenous midges as vectors of the African bluetongue virus

Culicoides spp. (biting midges)

Ceratopogonidae, Culicoides spp.(biting midges)

Smallest haematophagous insects(‚no-see-ums‘)

1-3 mm

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Foto Susanne Schneider

Insect bite hypersensitivity


Nuisance


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Vectors

•Bluetongue virus

•African Horse Sickness virus

•Toggenburg Orbivirus

•Epizootic Haemorrhagic Disease virus


Expansion of African BTV vector C. imicola northwards?

Native vectors of BTV !!!

Bluetongue in Europe

Bluetongue 2006

Bluetongue 2007/2008

??

?

? ? ?

prior

1998

after

1998

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“Bluetongue disease vectors (Culicoides spp.): Defining parameters which determine ‘vector free periods/areas’ in CH”

– Entomological monitoring

– Develop standardized Culicoides vector identification

Research project funded by FVO (no. 1.08.10)

Montoring of midges in Switzerland:choice of trapping sites

EU grid (45 x 45 km)

45 km

Swiss Federalism (26 cantons)

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Trapping sites in the 12 Swiss climatic regions

(Trans-) JuraMidland(Pre-, High-, Inner-) AlpsSouthern Switzerland

ZHBS

BE

GE

Trapping sites in the 12 Swiss climatic regions

• 12 farms with livestock

• Trapping weekly– Overnight

• All year round

• 3 years

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Trapping of Culicoides spp.

• Onderstepoort blacklight traps

Morphological identification

Sorting of Culicoides spp.:

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Morphological identification of Culicoides spp.

• Obsoletus group

– C. obsoletus– C. scoticus– C. dewulfi– C. chiopterus

• Pulicaris group

– C. pulicaris– C. impunctatus– C. punctatus– C. grisescens– C. newstaedi– ...more

• Other Culicoides

Develop standardised molecular vector identification

(multiplex real time PCR, MALDI-TOF)

0

2000

4000

6000

8000

10000

12000

Jan Feb Mrz Apr Mai Jun Jul Aug Sep

2008

Nu

mb

ers

of

Cu

lico

ides

Total Culicoides spp.Obsoletus groupPulicaris groupOther Culicoides

Monthly average of trapped Culicoides spp. in Dittingen (BL) (altitude 364 m)

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0

500

1000

1500

2000

2500

Jun Jul Aug Sep

2008

Nu

mb

ers

of

Cu

lico

ides

Total Culicoides spp.

Obsoletus groupPulicaris group

Other Culicoides

Monthly average of trapped Culicoides spp. in Juf (GR) (altitude 2126 m)

June 08

Monthly average of trapped Culicoides spp. in Switzerland, 2008

270 M.ü.M. 360 M.ü.M.

420 M.ü.M. 500 M.ü.M.

630 M.ü.M. 670 M.ü.M.

1010 M.ü.M.940 M.ü.M.

1710 M.ü.M.

1560 M.ü.M.1110 M.ü.M.

2130 M.ü.M.

Kaufmann et al., 2009; Tschuor et al., 2009

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Percentage of Culicoides groups with increasing altitude

0

10

20

30

40

50

60

70

80

90

100

Novazz

ano

Dittin

gen

Comm

uguy

Gra

nges

Wäd

ensw

il

Müh

leth

urne

n

Châtea

u d'O

ex

Engelb

erg

Chaum

ont

Davos

Samed

anJu

f

Cu

lico

ides

(%

)

Obsoletus group

Pulicaris group

Other

Altitude: 270 m 2130 m

Kaufmann et al., 2009

Culicoides spp. in Switzerland

Vector-free period: 15 December 2008 to 20 April 2009

No midges-free zones in all of the agriculturally utilized areas (including alpine summer pastures)

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BTV Vectors in Central Europe

No co-evolution of European midge vectors and African BTV

Co-evolution vs. ‚ecological fitting‘

(Colonization of novel environments by exploiting few conserved features)

Unpredictable outcome of novel vector-pathogen associations in new environments

Culicoides spp.: What we need to know

...host preferences

Resting places...

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Breeding places...

Emergence traps

Soil samples

Defined breeding substrates

Establish colonies of indigenous species (alpine, lowland origin)


Bionomics, vector competence, vector capacities ...

C. nubeculosus colony (Pirbright)

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Toggenburg-orbivirus TOV (Barbara Thür, IVI): - midges collection/identification - virus pre-propagation in midges

Insect bite hypersensitivity (Eliane Marti, Institut of Clinical Research, Uni BE)

Identification of responsible antigens in colony-reared and wild-caught midges

Culicoides collaborative projects

Durch Arthropoden übertragene Pathogene in der Schweiz:


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Arthropod-vector pathogen host

- Babesia bigemina cattle

Ixodes ricinus ticks Babesia capreoli chamois

Phortica variegata flies Thelazia eye worm dog, cat, fox

Aedes japonicus mosquito ?

Culicoides spp. midges bluetongue virus ruminants

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Verdankungen

UniversityZurichUZH

institute of parasitology (ipz) medical and vetsuisse...

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