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
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)
• Diurnal biting activity
• Exo/endophagic species
Aedes aegypti
bionomics in Madeira
0
0.5
1
1.5
2
2.5
6h 7h 8h 9h 10h 11h 12h 13h 14h 15h 16h 17h 18h 19h 20h 21h 22h 23h 00h 1h 2h 3h 4h 5hMe
an f
em
ale
Ae
. ae
gyp
ti/c
olle
cto
r
Hours
Daily female Ae. aegypti indoors biting pattern
0
0.5
1
1.5
2
2.5
6h 7h 8h 9h 10h 11h 12h 13h 14h 15h 16h 17h 18h 19h 20h 21h 22h 23h 00h 1h 2h 3h 4h 5hMe
an f
em
ale
Ae
. ae
gyp
ti/c
olle
cto
r
Hours
Daily female Ae. aegypti outdoors biting pattern
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
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)
Gru
po e
tári
o (
anos)
F
M
Outbreak outline
.000
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
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
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
• 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
0
0.5
1
1.5
2
2.5
3
3.5
4
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
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
0
50
100
150
200
250
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
–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
0
50
100
150
200
250
300
350
400
450
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
40_12 41_12 42_12 43_12 44_12 45_12 46_12 47_12 48_12 49_12 50_12 51_12 52_12 01_13 02_13 03_13 04_13 05_13 06_13 07_13 08_13 09_13
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)
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
2009 2012 2013
V1016I F1534C
(66) (87)
(91)(66)
(69)
(65)
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
P o p u la tio n s o f A e . a e g y p ti te s te d
nm
ol/
mg
ptn
/min
Ro
ckefe
ller
Fu
nch
al
Paú
l d
o M
ar
0
5 0
1 0 0
1 5 0
2 0 0
E n zy m a tic p ro file o f b e ta e s te ra s e a c tiv ity
P o p u la tio n s o f A e . a e g y p ti te s te d
nm
ol/
mg
ptn
/min
Ro
ckefe
ller
Fu
nch
al
Paú
l d
o M
ar
0
5 0
1 0 0
1 5 0
2 0 0
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?
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