dengue in thailand worskop 2012/diaden... · aedes albopictus vector /a secondary vector of viruses...
TRANSCRIPT
Theeraphap Chareonviriyaphap
Department of Entomology
Kasetsart University Bangkok, Thailand
DENGUE IN THAILAND
Dengue is a mosquito-borne viral disease
Viruses can be transmitted to humans by the bite of
infective female mosquitoes
Transmission by Aedes mosquitoes: Aedes aegypti &
Ae. albopictus
TRANSMISSION CYCLE
Transmission of Dengue Virus
1. Virus is transmitted to
human from mosquito saliva
2. Virus replicates in target
organs
3. Virus infects white blood cells and lymphatic tissues
4. Virus released and circulates in blood
www.cdc.gov/.../slideset/set1/i/slide05.htm
World distribution of dengue viruses, 2008
DISEASE POP AT POP ENDEMIC MORTALITY MORBIDITY
RISK INFECTED COUNTRY
(MILLION) (MILLION)
MALARIA 2400 >500 90 1.5-3 300-500
M/Y M/Y
CHAGAS 90 18 21 45000/Y 3 M
SCHISTO
SOMIASIS 600 200 74 20,000/Y 20 M
FILARIA 750 75 70
DENGUE 2000 MILLION >100 1-5% MILLIONS
DHF cases and case fatality rate in Asia, 2006-2008
Morbidity Rate of DF and DHF in Thailand (2003-2009)
0
10
20
30
40
50
60
70
80
90
2003 2004 2005 2006 2007 2008 2009
Year
Mo
rbid
ity R
ate
/ 100,0
00 P
op
.
DF
DHF
Morbidity Rate of DHF by region in Thailand (2003-2009)
0
20
40
60
80
100
120
140
2003 2004 2005 2006 2007 2008 2009
Year
Mo
rbid
ity R
ate
North
Central
Northeast
South
1 5 10 15 20 25 30 35 40 45 50
2009
Number of DHF cases by week of onset and region in Thailand, 2009
Rainy season Cool season
Hot season Cool season
0.01-10
>10-25
>25-50
>50-100
>100-200
Province:
Samutprakan, Chonburi,
Nakhonpathom, Rayong , Samutsakhon.
Morbidity Rate
Distribution of DHF in Thailand in 2009
Mosquitoes in Thailand (2006) Anopheles 73 species Aedes 164 species Culex 144 species Toxorhynchites 12 species Uranotaeniini 45 species
Dengue Vectors
http://www.cdc.gov/ncidod/dvbid/dengue/slideset/spanish/set1/i/slide07.htm
http://www.wbrcouncil.org/CatSubCat/CatSubCatdisplay.asp?p9=CSC1&p1=119&p7=36
Aedes aegypti Aedes albopictus
Aedes aegypti Ae. albopictus
2-3 days
2-3 days
7-12 days 4-6 weeks
Aedes aegypti A primary vector of dengue & chikungunya
Originated from Africa, spread around the word ,
mainly in urban area
Likely to rest and feed indoor / around human dwelling ( esp. dark area)
Primarily a daytime feeder
Lays eggs and produces larvae preferentially in artificial containers
Adult resting area
Larval breeding site in town
Larval survey in village
Larval breeding site in rural
Aedes albopictus Vector /a secondary vector of viruses such as dengue
viruses, Chikungunya, etc.
Origin in the forests of Southeast Asia mainly occurs in rural & suburban areas.
Exophagic and exophilic mosquito
The larval breeding sites of Ae. albopictus are very broad and range from natural sites to artificial containers
Tree hole
Bamboo stump Banana pedal
Palm plantation
Waterfall
Orchard
Public park
Rubber plantation
MOSQUITO CONTROL
Chemical Control
Physical control
Biological Control
Trap Technology
Repellent
Chemical control
Physical control
Biological control
Trap technology
Repellent
References
Bureau of Epidemiology, Department of Disease Control, Ministry of Public Health.
http://www.cdc.gov/ncidod/dvbid/dengue/slideset/spanish/set1/i/slide07.htm http://www.wbrcouncil.org/CatSubCat/CatSubCatdisplay.asp?p9=CSC1&p1=119&p7=36
KASETSART UNIVERSITY