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Vector-borne diseases - Dengue outbreak in Madeira Island

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Vector-borne diseases - Dengue outbreak in Madeira Island

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Vector-borne diseases - Dengue outbreak in Madeira Island

  1. 1. 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 * casousa@ihmt.unl.pt
  2. 2. Madeira: the garden island • For Aedes aegypti too…
  3. 3. Aedes aegypti in Madeira Island • 2005: First record of the mosquito– Funchal (St.Luzia) • Rapid dispersal in the southern part of the island
  4. 4. 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)
  5. 5. • Seasonality pattern Aedes aegypti bionomics in Madeira
  6. 6. • 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 5h MeanfemaleAe.aegypti/collector 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 5h MeanfemaleAe.aegypti/collector Hours Daily female Ae. aegypti outdoors biting pattern
  7. 7. • Man-biting rates Aedes aegypti bionomics in Madeira
  8. 8. Aedes aegypti bionomics in Madeira Pictures: ECDC -2012  Main breeding sites – Peridomestic containers – Abandoned houses (?!?!)
  9. 9. • 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
  10. 10. 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
  11. 11. Origin of A. aegypti population One (?) single haplotype for both COI and ND4 (N=15) Distribution of kdr mutation 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
  12. 12. Dengue outbreak in Madeira
  13. 13. Dengue outbreak in Madeira • First transmission areas – St. Luzia and Nazaré
  14. 14. • Affected areas according to patients residence Dengue outbreak in Madeira
  15. 15. • Affected areas according to patients residence Dengue outbreak in Madeira
  16. 16. Dengue outbreak in Madeira Number of disease cases between week 39 of 2012 and week 3 of 2013 Alert Outbreak Sporadic cases Sporadic cases
  17. 17. 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
  18. 18. • 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) Grupoetário(anos) F M
  19. 19. 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
  20. 20. • 82 dengue cases in 14 countries imported from Madeira
  21. 21. 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
  22. 22. Epidemiological monitoring and information gathering Epi-bulletin
  23. 23. Madeira Dengue Surveillance System (MDSS) Hospitals and public health centres E- Bulletin Private health centres Web form Bi-weekly extraction during the outbreak Weekly extraction on-going Data Management IASAUDE,I-RAM- DSPAG/UTEIS/UES CC DROTA Time Person Place Stakeholders Regional Nacional International Authorities Time-space analyse Vector control Vector monitoring activities
  24. 24. Intra/inter-sectorial collaboration INSA
  25. 25. • 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
  26. 26. 0 0.5 1 1.5 2 2.5 3 3.5 4 Mean number of Ae. aegypti females collected from January 2012 to January 2013 on BG traps Female aegypti Bimensal work basis Daily work basis Vector monitoring
  27. 27. 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
  28. 28. • 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. Luzia 12-11-2012 Vector monitoring (and control)
  29. 29. • Infestation indexes (2009) Funchal Câmara de Lobos St Cruz All counties N. houses surveyed 273 125 22 420 N. of containers inspected 1681 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
  30. 30. • Educational campaigns for aegypti source reduction Vector control during Dengue outbreak “She hanging around!” Flyers and posters Internet update information
  31. 31. • Educational campaigns for aegypti source reduction Vector control during Dengue outbreak TV spot RTP Madeira 2012
  32. 32. • 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
  33. 33. –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
  34. 34. –Flushing of storm drains with sea water. Vector control during Dengue outbreak
  35. 35. –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
  36. 36. 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
  37. 37. Post-outbreak activities • On-going heath education programs • Search for an efficient mosquito adulticide • Studies on resistance mechanisms • Alternative strategies for vector control
  38. 38. • Highly resistant Aedes aegypti population to pyrethroids, carbamates, organochlorines and organophosphates
  39. 39. • 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)
  40. 40. Metabolitic resistance E n zy m a tic p ro file o f a lfa es teras e ac tivity P o p u la tio n s o f A e . a e g y p ti te s te d nmol/mgptn/min R o c k e fe lle r F u n c h a l P a ú l d o M a r 0 5 0 1 0 0 1 5 0 2 0 0 E n zy m a tic p ro file o f b eta es te ra s e ac tiv ity P o p u la tio n s o f A e . a e g y p ti te s te d nmol/mgptn/min R o c k e fe lle r F u n c h a l P a ú l d o M a r 0 5 0 1 0 0 1 5 0 2 0 0
  41. 41. Alternative strategies for vector control • Auto dissemination of Pyriproxifen (juvenile hormone): DENFREE consortium – Pilot study in Paúl do Mar
  42. 42. Alternative strategies for vector control • Water treatment in cemeteries with Bti (mosquito biocide)
  43. 43. Alternative strategies for vector control • Evaluation of salt as a control strategy for storm drains treatment. – Funchal county
  44. 44. 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?
  45. 45. Obrigada

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