Vector-borne diseases - Dengue outbreak in Madeira Island

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Sousa C.A.*, Seixas G., Novo M.T., Vacas D. , Clairouin M. , Viveiros B. Magalhães M., Baptista M., Valente C., Gonçalves Y. , Gonçalves Silva J.J., Antunes L.C. , Araújo D., Silva A.C Dengue outbreak in Madeira island * [email protected]

Transcript of Vector-borne diseases - Dengue outbreak in Madeira Island

Sousa C.A.*, Seixas G., Novo M.T.,

Vacas D. , Clairouin M. , Viveiros B.

Magalhães M., Baptista M., Valente C.,

Gonçalves Y. , Gonçalves Silva J.J.,

Antunes L.C. , Araújo D., Silva A.C

Dengue outbreak in

Madeira island

* [email protected]

Madeira: the garden island

• For Aedes aegypti too…

Aedes aegypti in Madeira Island• 2005: First record of the mosquito– Funchal (St.Luzia)

• Rapid dispersal in the southern part of the island

Vector Monitoring

Since 2005-6, IHMT is participating in mosquito related activities with local health authorities (IASAUDE)

• Identification of mosquito presence in the island.

• Bionomics studies

• Surveillance/monitoring activities

• Insecticide susceptibility bioassays (WHO)

• Genotpying of knockdown resistance (kdr) mutations

– AS-PCR and sequencing

• Population structure and history (mtDNA and microsatellites)

• Seasonality pattern

Aedes aegypti bionomics in

Madeira

• Diurnal biting activity

• Exo/endophagic species

Aedes aegypti

bionomics in Madeira

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Daily female Ae. aegypti indoors biting pattern

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Daily female Ae. aegypti outdoors biting pattern

• Man-biting rates

Aedes aegypti bionomics in

Madeira

Aedes aegypti bionomics in Madeira

Pictures: ECDC -2012

Main breeding sites– Peridomestic containers

– Abandoned houses (?!?!)

• Main breeding sites

– Storm drains.

Aedes aegypti bionomics

Total number of storm drains (ST) 434

% of dry ST 56,6%

% of negative ST 27,9%

% of ST with mosquito immature 15,7%

% of ST with Ae. aegypti 12,2%

% Absolute breeding index for aegypti 0,28

WHO insecticide resistance tests- 2009 DDT 4.0% - 33.3% mortality

Malathion 5.0% - 99.0% mortality (diagnostic dosage 0.8% /1h- 2012)

Permethrin 0.75%, - 29.4% mortality

Deltamethrin 0.05% - 65.2% mortality

Detection of 4 kdr mutations (N=35) Presence of only one mutation, V1016I

In homozygosity, in an one DDT-resistant individual

In heterozygosity, in 2 permethrin-resistant individuals

Origin of A. aegypti population

One (?) single haplotype for both COI and ND4 (N=15)

Distribution of kdrmutation V1016I

Probable origin of Ae. aegypti

Madeira

Venezuela

México

Senegal

BrazilPeru

EUA

Guatemala

Colonization by insecticide resistant mosquitoes

Stream traffic of people and goods

mtDNA analysis

Dengue outbreak in Madeira

Dengue outbreak in Madeira

• First transmission areas – St. Luzia and Nazaré

• Affected areas according to patients residence

Dengue outbreak in Madeira

• Affected areas according to patients residence

Dengue outbreak in Madeira

Dengue outbreak in Madeira

Number of disease cases between week 39 of 2012 and week 3 of 2013

Alert

Outbreak

Sporadic cases

Sporadic cases

Outbreak outline

• W39 2012 –W06 2013 : 20 weeks

• Probable cases : n= 2168– 3 municipalities : n= 2069 cases 95 % cases

• Sex ratio (M/F) = 0.69

• 128 hospitalizations

• NO FATALITIES

Dengue outbreak in Madeira

Female

Male

• Incidence rate/ gender/ age group

Outbreak outline

39.3

59.9

110.1

128.3

70.6

70.9

73.5

68.5

57.3

72.1

75.9

54.8

69.2

67.8

77.9

25.5

34.7

45.6

31.9

49.4

78.4

117.6

90.8

82.4

96.3

92.0

111.1

108.2

132.7

118.9

113.3

73.0

68.0

70.8

55.1

39.9

0.0 20.0 40.0 60.0 80.0 100.0 120.0 140.0

0-4

5-9

10-14

15-19

20-24

25-29

30-34

35-39

40-44

45-49

50-54

55-59

60-64

65-69

70-74

75-79

80-84

85+

Taxa de incidência (/10.000 hab)

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Outbreak outline

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10.000

20.000

30.000

40.000

50.000

60.000

70.000

80.000

90.000

100.000

Febre

Mialgia

Cefaleia

Exantema

Dor retro Orbitária

Altralgia

Manifestações Hemorrágicas

Diarreia

Positivos Negativos

• Lab : 3285 samples analysed

• 82 dengue cases in 14 countries imported from Madeira

Outbreak response activities

• Epidemiological monitoring and information gathering

- Case definition for surveillance, epi-bulletin.

• Prevention and treatment

- Door-to-door campaigns and residence visits, public awareness

- Vector monitoring and control

- Specific dengue patient care management (severe and non-severe cases)

- Blood safety: challenge at the start o the outbreak (PCR)

• Intra/inter-sectorial collaboration

• Communication plan: different media / prevention and control breeding sites

• Internal and external evaluation

Epidemiological monitoring and information gathering

Epi-bulletin

Madeira Dengue Surveillance System (MDSS)

Hospitals and public health centresE- Bulletin

Private health centres

Web form

Bi-weekly extraction during the outbreak Weekly extraction on-going

Data Management

IASAUDE,I-RAM- DSPAG/UTEIS/UESCC DROTA

Time Person Place

StakeholdersRegionalNacional

International Authorities

Time-space analyse

Vector control Vector monitoring activities

Intra/inter-sectorial collaboration

INSA

• Aedes aegypti monitoring during the outbreak

– 16 Bg-sentinel traps in the most affected areas.

– 141 ovitraps located in Aedes aegypti distribution area.

– Door-to-door larval sampling in the areas with higher

number of disease cases

Vector monitoring

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Mean number of Ae. aegypti females collected fromJanuary 2012 to January 2013 on BG traps

Female aegypti

Bimensal work basis Daily work basis

Vector monitoring

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Population dynamics of Aedes aegypti

Mean eggs/trap Mean Aegypti F

Vector monitoring

• Door-to-door activities - Educational Health

program • Breeding sites reduction

• Measures for personal protection against aegypti bites and

virus infection

– Monitoring and elimination of breeding sites

• Infestation indexes

St. Luzia12-11-2012

Vector monitoring (and control)

• Infestation indexes (2009)

FunchalCâmara de

LobosSt Cruz All counties

N. houses surveyed 273 125 22 420

N. of containers inspected1681 1298 431 3410

House Index (%) 32.9 12.0 45.5 27.4

Container Index (%) 12.8 3.8 3.5 8.2

• Abandoned/closed

houses

• Educational campaigns for aegypti source

reduction

Vector control during Dengue

outbreak

“She

hanging

around!”

Flyers and posters

Internet update information

• Educational campaigns for aegypti source

reduction

Vector control during Dengue

outbreak

TV spot

RTP Madeira

2012

• Educational campaigns for aegypti source

reduction

– TV and Radio Programs

– 11 Radio-spots

Information on airports and passenger

harbour (5 languages)

Vector control during Dengue

outbreak

Information to tourists in hotels and other accommodation facilities

– Increased mosquito surveillance in airport

and harbours

–Cleaning of public artificial lakes and

ponds and dispersal of carnivorous

autochthonous fishes

–Flushing of storm drains with sea water.

Vector control during Dengue

outbreak

–Flushing of storm drains with sea water.

Vector control during Dengue

outbreak

–Application of larvicides and adulticides

at specific locations:

Vector control during Dengue

outbreak

Hospital Dr. Nélio Mendonça

Centro de saúde Bom Jesus

Escola Secundária

Francisco Franco

Impact of vector control measures

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Aedes aegypti adult densities and dengue cases

Mean Aegypti F Dengue cases

Post-outbreak activities

• On-going heath education programs

• Search for an efficient mosquito adulticide

• Studies on resistance mechanisms

• Alternative strategies for vector control

• Highly resistant Aedes aegypti population to pyrethroids, carbamates, organochlorines and organophosphates

• F1534C mutation is fixed (0.98-1.00)• V1016I mutation is increasing (0.07-0.17)

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V1016I F1534C

(66) (87)

(91)(66)

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Metabolitic resistance

E n zy m a tic p ro file o f a lfa e s te ra s e a c tiv ity

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Alternative strategies for vector control

• Auto dissemination of Pyriproxifen

(juvenile hormone): DENFREE

consortium

– Pilot study in Paúl do Mar

Alternative strategies for vector control

• Water treatment in cemeteries with Bti (mosquito

biocide)

Alternative strategies for vector control

• Evaluation of salt as a control strategy for storm

drains treatment.

– Funchal county

Remarks & perspectives

• No autochthonous dengue cases reported in Madeira since February

2013

• Well established recently introduced Aedes aegypti population

– Distribution appears to be regressing (Central/south)

• mtDNA analysis inconclusive

– Single introduction?

– South American (Venezuela) origin?

– Human migratory flux with Brazil and Venezuela

• High levels of resistance to pyrethroid insecticide

– Environmental control (flushing storm drains w/ sea water )

– Alternative insecticides (ongoing pyriproxyfen pilot-study)

– Genetic control?

Obrigada