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Invasive mosquito vectorsan overview

Invasive mosquito vectorsan overview

Roger Eritja

ECDC/RKI, Berlin, Jan 2012

IMPORTED VECTORS

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Moving thousands per year: +95 mosquito species foundon aircraft surveys, 1920-1970(Gratz et al.)

May help vector establishmentCan enable transmission cycles

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Asian invasive species

Readily bites humans

Aedes albopictusThe Asian Tiger Mosquito

Readily bites humans

Likely to colonize commercial goods

Occurs in urban landscapes

Adapted to container breeding

TIGER IMPACTS

Mostly breeds within private propertiesPublic MCS cannot carry on control measures

Daytime biting species - from May to NovemberPermanent exposure to nuisance in gardens and yards

Aggressive repetitive biterReally difficult to cope with dense populations

Dermic problems are frequentIt takes some time to immunize to exotic saliva

Uses manmade containersAbundant, difficult to spot, not perceived as wrong

It’ tl td biti iIt’s mostly an outdoor biting speciesCommon household pesticides are useless

AS A RESULT..

People receive all-day high biting rates (30 to 90+ per hour)from aggressive mosquitoes preventing any outdoor activity.

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Not at all a large mosquito (4-5 mm) :

MORPHOLOGY OF AEDES ALBOPICTUS

Black-and-white aspect

White kneesWhite knees

MORPHOLOGY OF AEDES ALBOPICTUS

Striped aspectStriped aspect

Diagnostic white sagital stripe Diagnostic white sagital stripe over head and thoraxover head and thorax

BlackBlack--andand--white striped legswhite striped legs

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FLAVIVIRUSES

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BUNYAVIRUSES

VECTORIAL COMPETENCES OF AEDES ALBOPICTUS

Dengue West NileYellow FeverJapanese Encephalitis

ALPHAVIRUSES

Western Equine EncephalitisEastern Equine Encephalitis

Jamestown CanyonKeystoneLaCrosseOropouchePotosiFiebre Rift ValleySan AngeloTrivittatusCache ValleyTensaw

(Mitchell 1994, Nayar & Knight 1999, Gerhardt et al. 2001, Holick et al. 2002)

q pVenezuelan Equine EncephalitisChikungunyaSindbisMayaroRoss River fever

NEMATODA

Dirofilaria immitis

CHIKUNGUNYA OUTBREAK, ITALY 2007

Index case: traveller from India, June

Most of the affected people in 2 locations: Castiglione di Cervia & Castiglione di Ravenna, 3.700 pooled inhabitants.

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EUROPEAN ALBOPICTUS-MEDIATED OUTBREAKS

COUNTRY LOCATION CASES VIRUS YEAR TIMECOUNTRY LOCATION CASES VIRUS YEAR TIME

Italy Cervia 217 Chikungunya 2007 June - Sept

France Nice 3 Dengue 2010 September

France Fréjus 2 Chikungunya 2010 September

Croatia Podobuce 3 Dengue 2010 August-Sept

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Week 32 (2nd week of August)Peak Aedes albopictus densities

ENTOMOLOGICAL OUTBREAK FACTORS

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1 2 3 4 5 6 7 8 9 10111213141516171819202122232425262728293031323334353637383940414243444546474849505152

Week 17 (last week of April)First Aedes albopictus

Week 46 (mid-November)Last Aedes albopictus

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SPREADSPREAD

WORLDWIDE INVASION BY AEDES ALBOPICTUS

1985: U.S.A.

A theoretical limit to the North

Before 1905

1979: Albania

1990: Italy

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TIGER SHIPPING

Lucky Bamboo (Dracaena sanderiana)

Used tires

AN INTERCONTINENTAL VIEW OF TWO PATHWAYS

1985, Tires

ChinaAlbania Japan

US - TexasItaly

US - California

1979, goods

1991, Tires

2001, Lucky Bamboo

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DETECTION IN SPAIN (AUGUST 9, 2004)

Carles Aranda captures two adult mosquitoes in a house in downtown

Sant Cugat del Vallès, near Barcelona

Th f th id tifi d A d They are further identified as Aedes albopictus (Aranda et al. 2006).

FINAL 2004 ASSESSMENT

• The mosquito population was already established at least two years ago

• Widespread within the municipality and one additional neighbour town

• Eradication impossible

• Warning reports issued to Catalan and Spanish governments

• Immediate action required to stop dispersal to other municipalities

• Cost for emergency measures estimated at 0.5 M €:

LarvicidingLarvicidingAdulticidingSanitationRaising public awarenessEnvironmental managementMonitoring

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SOURCES:Consell Comarcal Baix LlobregatA. Torrell - Generalitat de CatalunyaE. Marquès - MMVSCMBRBT

WHAT HAPPENED LATER?

2010 183 5,641,016 4,0792009 128 5,053,473 3,111

2006 27 2,763,749 612

Year Mun Hab Km2

2004 2 132,103 79

2007 55 3,922,072 1,0382008 98 4,614,962 2,200

2005 11 2,106,174 341

Used tire dumping placeUsed tire dumping place

ROAD NETWORK AS A PREDICTORA7 (from France & Italy)A7 (from France & Italy)

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LOCAL FACTORS

Mean temperatureMean temperatureHipsometryHipsometry

Secondary homesSecondary homesHuman population densityHuman population density

CONTROLCONTROL

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INTEGRATED CONTROL AGAINST AE.ALBOPICTUS

CHEMICAL CONTROL: AN EMERGENCY TOOL

Used for eradication (wherever possible), density reduction in public areas (parks, cemeteries) or emergency resource.

Not really sustainable but necessary; limited by the new EU Directive on urban pesticiding.

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BIOLOGICAL CONTROL: BIORATIONAL LARVICIDES

• Insect Growth regulators (IGRs)

• Chitin synthesis inhibitors such as Diflubenzuron;

• Juvenoid hormone mimics such as Pyriproxyfen

• Microbial larvicides

• Bacillus thuringiensis(serotype israelensis)

• Bacillus sphaericus

They are safe and effective, highly selective and have an excellent toxicological profile.

However, only 20 to 40% of the breeding places are in public areas

So that they are not the primary tool against Aedes albopictus.

BIOLOGICAL CONTROL: BIORATIONAL LARVICIDES

They are safe and effective, highly selective and have an excellent toxicological profile.

However, only 20 to 40% of the breeding places are in public areas

So that they are not the primary tool against Aedes albopictus.

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COMMUNITY-BASED INFORMATION CAMPAIGNS

AEDES ALBOPICTUS CONTROL IN THE BAIX LLOBREGAT

BIOCIDES• Adulticiding in public, sensitive places: cemeteries, schools, parks.

• Systematically larviciding catch basins & other urban foci: 135,500 catch basins treated in 2011 with biorational pesticides.

TECHNICALINSPECTIONS

• Visiting homes at no cost upon homeowner request: 411 visits in 2011.

• Studying and performing specific physical actions (i.e. treeholes in urban vegetation, cemetery vases, advising about design of urban structures).

• Monitoring mosquito population densities.

INFORMATION EDUCATION

• Broadcasting messages, mass media, public chats to interest groups.

• Person to person information to all houses, using local citizenship agents: 183,000 leaflets distributed in hand since 2009.

Workshops at primary schools: 6 850 primary students since 2009• Workshops at primary schools: 6,850 primary students since 2009

• Promotion of legislative changes.

RESEARCH

• 2007: Assessment of efficacy of metallic copper in local cemeteries.

• 2008-09: Testing ground-based, aerial larviciding using bacterial larvicides.

• 2008-11: Social psychology/entomology project on social behaviour relative to the Tiger mosquito: responses to public campaigns, and relationship to any reduction of mosquito density.

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INFORMATION: THE MAILBOX ATTACK

THE MAILBOX ATTACK

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AEDES ALBOPICTUS AS A SOCIOLOGICAL PROBLEM

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Estadístics setmanals d'activitat per Ae.albopictusDades ponderades - Tots els anys sumats

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Ous per trampa Queixes per tigre Comunicacions web Tmean

PROBLEMS IN ALBOPICTUS CONTROL

Legal issuesBy law, public pest control in Spain is the fate of municipalities, although an invasive species is not exactly a local problem. Thus, governments are not forced to draw any attention on this.

Jurisdiction Most breeding places cannot be larvicided as they are in private properties and anyway couldn’t be weekly treated. We need inhabitants getting rid of containers.

CultureMany inhabitants keep containers because they do not beieve they are a problem. Then, mosquito densities raise at home. As a result, they increasingly claim for adulticiding.

Comm nicationPublic awareness campaigns are well established. However, one needs to ensure th th h d th t l k it l bl d i Thi i Communication the message passes through, and that people keep it as a valuable advice. This is not achieved by just printing leaflets; social communication is necessary.

Leadership

Attitudes in Public Administration are not always as proactive as they might be. As an example, easy solutions for cemetery vases such as drilling are not widely implemented yet, due to administrative fears. Impossible to persuade homeowners if municipalities don’t do their homework!

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THE NEW INVASIVES MAYBE NOT THAT NEW ?

THE NEW INVASIVES MAYBE NOT THAT NEW ?

Aedes albopictusAlbania 1979 Established and

spreadingSouthern Europe 1990-2011

France † 2000 Accidental

INVASIVE MOSQUITO SPECIES (IMS) 1979-2011

Aedes japonicus

Belgium 2002

Established and spreading

Switzerland 2008

Germany 2008

Austria 2011

Slovenia 2011

Russia 2001

EstablishedMadeira 2004Aedes aegypti

EstablishedMadeira 2004

Georgia 2007

Netherlands 2010 Accidental

Aedes koreicusBelgium 2008

EstablishedItaly 2011

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OTHER EVENTS OF IMPORTED MOSQUITO SPECIES

Aedes atropalpus Italy 1996 Established, not spreading

France 2003 Accidental

Netherlands 2009 Established, not spreading

Aedes triseriatus France 2004 Accidental

To o h nchites Toxorhynchites rutilus France 2004 Accidental

Orthopodomyia signifera France 2004 Accidental

A close relative: Aedes aegypti

in Spain by the XVIIIth c.

A close relative: Aedes aegypti

in Spain by the XVIIIth c.

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AN OLD, WELL-KNOWN RELATIVE

Aedes aegyptiAedes aegyptiAedes aegyptiAedes aegyptiAedes albopictusAedes albopictusAedes albopictusAedes albopictus

Laboratory-competent Dengue vector Considered the main Dengue vector in the field

Asian origin Believed African origin

© CDC© CDC

Hibernating strains Non-hibernating

Present in Mediterranean area Extinct from the Mediterranean

Rural & urban habitats Urban habitat

Attacks birds & mammals Strongly anthropophilic

Sylvatic peri-urban Urban

Invasive-present Invasive in the past

Historic spreadof Aedes aegypti

(indirectly tracked by Yellow Fever)

Historic spreadof Aedes aegypti

(indirectly tracked by Yellow Fever)

Yellow Fever in Yellow Fever in Europe

No evidences before XVIIIth c.

It is hypothesized that both vector and the disease were introduced to the New World through African slave trade.

Aedes aegyptiSupposedly of African origin with some Asian

populationsYellow Fever in the

New WorldNeither Columbus nor

his contemporaries describe YF; first

evidence is from XVIth.

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Historic spreadof Aedes aegypti

(indirectly tracked by Yellow Fever)

Historic spreadof Aedes aegypti

(indirectly tracked by Yellow Fever)

Increasing goods commerce from the New World imports the vector within vessel water reserves –

d th di ithi th

Yellow Fever in the New World

First documented epidemy: 1648 – Yucatán

Yellow Fever in Europe

First epidemies: Gibraltar 1649, Canary is. 1701, Cádiz 1731.

and the disease within the crew.

YELLOW FEVER IN SPAIN (1700-1850)

Barcelona Barcelona 18701870

* More than 500,000 dead by YF (1800-1850)* Added 5% Dengue mortality

Lisboa Lisboa 17231723

Barcelona Barcelona 18211821

CádizCádiz1730~1730~17641764

Baleares Baleares

Lisboa Lisboa 18561856

Madrid Madrid 18781878

Baleares Baleares 18701870

(Rico-Avelló y Rico, 1953)

MálagaMálaga17411741

Canarias Canarias 1701 1701

Baleares Baleares 17441744

CádizCádizSevillaSevillaJerezJerez

1800~18031800~180360.000 60.000

muertosmuertos

AlicanteAlicante1804,1804,18111811

GibraltarGibraltar16491649

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AEDES AEGYPTI CITED IN SPAIN (1899-1944)

PlasenciaPlasencia1944 (?)1944 (?)Romeo Romeo

ViamonteViamonte

Huesca Huesca 1929 (?)1929 (?)(Elvira)(Elvira)

TarragonaTarragonay Levante y Levante

19121912(Pittaluga)(Pittaluga)

Barcelona Barcelona 19391939

(Margalef)(Margalef)

GibraltarGibraltar18991899

(Birt & (Birt & Yomber)Yomber)

MenorcaMenorca19111911(Arias (Arias

Encobet)Encobet)

Canarias Canarias 19051905

(Pittaluga)(Pittaluga)

HYPOTHESIS ABOUT THE EXTINCTION OF AEDES AEGYPTI

• Malaria control programs affected also Ae.aegyptiUnlikely, as biotopes were totally disjunct

• Stopping continuous re-introduccions by maritime commerce

• Enhancements of health conditions in urban settlements

• Lack of adaptation to temperate climateUnlikely by itself at the regional level, as in the Americas the species does very well in Mediterranean-like climatic areasdoes very well in Mediterranean like climatic areas

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PRESENT DISTRIBUTION OF AEDES AEGYPTI (2000)

Madeira 2004establishedMadeira 2004established

Netherlands 2010eradicatedNetherlands 2010eradicated

Ukraine 2001- ?establishedUkraine 2001- ?established

IS AN EUROPEAN RE-INVASION BY AEGYPTI POSSIBLE?

• Its adaptation to cold is lower than of Aedes albopictus(4,4o C vs. 0o C), which would confine it to certain areas

lonly.Save climatic change issues and modelling the Madeira local conditions, where it is established since 2004.

• Possible competition with albopictus if already present, at least in rural areas.

• Lack of hibernating physiology.

• Believed lower abilities in colonizing commercial goods such as tyres.However, the Madeira invasion could have been mediated by vegetal shipments. Additionally, it has been commonly found in airplanes.

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Prospectives in invasive mosquito species

Updating entomological information across Europe

Promoting monitoring, especially in countries at risk.Establishing reliable climate and socio-geographical models that could be used for

prevention.prevention.

Realistically assessing health risks

Making a unique European’s mind (if there’s such a thing) about the associated health risks, also considering loss of quality of life.

Assessing thoroughly the vector capacity of new species and of Aedes albopictus under local conditions.

Promoting control action

Promoting research on new control methods and productsPromoting research on new control methods and products.Promoting legislative changes at the EU level to support mosquito control operations –

not to suppress them.

Setting up coordination networks

Establishing guidelines for monitoring and early eradication interventions.Pushing member countries to support active operations from municipality to state

level.