MINISTRY OF HEALTH THE SOCIALIST REPUPLIC OF VIETNAM NATIONAL INSTITUTE OF MALARIOLOGY-PARASITOLOGY AND ENTOMOLOGY --- Independence – Freedom – Happiness --- Ph.D THESIS SUMMARY SU
Trang 1MINISTRY OF HEALTH THE SOCIALIST REPUPLIC OF VIETNAM NATIONAL INSTITUTE OF
MALARIOLOGY-PARASITOLOGY
AND ENTOMOLOGY
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Independence – Freedom – Happiness
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Ph.D THESIS SUMMARY SUBMITTING TO THE WEBSITE OF THE MINISTRY OF EDUCATION AND TRAINING
Thesis title: “Studies on distribution, behaviour and insecticide susceptibility status of Aedes aegypti and Aedes albopictus in Binh Dinh and Gia Lai provinces (2016-2018)”
The objectives of the study are:
1 Determination of the distribution, behaviour and prevalence of Dengue virus in Aedes aegypti and Aedes albopictus at study sites in Binh Dinh and Gia Lai provinces (2016-2018)
2 Evaluation of the susceptibility to some insecticides and kdr gene mutation of Aedes aegypti and Aedes albopictus in study sites
Major: Entomology; Code: 62.72.01.16
Ph.D Student: Do Van Nguyen
Promotors:1 Dr Nguyen Xuan Quang 2 Dr Huỳnh Hồng Quang
Training institution: National Institute of Malariology, Parasitology and Entomology (NIMPE)
Main findings of the thesis:
1 Distribution, behaviour and Dengue virus infection rate of Aedes aegypti and Aedes albopictus at study
sites in Binh Dinh and Gia Lai provinces (2016-2018)
1.1 Distribution and Dengue vector indices
Aedes aegypti and Aedes albopictus populations were found in all landscapes of Binh Dinh and Gia Lai provinces, except mountainous landscapes where Aedes albopictus was not found
Binh Dinh province: Aedes aegypti and Aedes albopictus accounted for 97.1% and 2.9% respectively The highest density index of Ae aegypti was recorded in urban areas (0.9 mos/house), flatlands (0.83
mos/house) in 10/2016, in mountainous areas in 10/2016 (0.7 mos/house) Similarly, in urban areas the
BI index was the highest in 10/2017, in flatlands and mountainous area the highest BI index was recorded
in 10/2016 (BI: 56); In Gia Lai province, Aedes aegypti and Aedes albopictus accounted for 88.1% and 11.9% respectively The DI index of ae aegypti was the highest in urban areas in 8/2017 (0.6 mos/house), rural areas 1 in 10/2016 (0.7 mos/house), rural areas 2 in 6/2016 and 8/2017 (0.45 mos/house) BI of Ae aegypti was highest in urban areas in 10/2017 (74), rural areas 1 in 12/2016 (92) and rural areas 2 in 12/2016 (77)
1.2 Behaviour and larve sources of Aedes aegypti and Ae albopictus
Binh Dinh province: Adult of Ae aegypti were collected mainly indoor (99.4%) and resting in clothes
(75.7-86% follow landscapes), bed net (10.9%-17.9% follow landscapes) and found resting on the wall in urban (1.3%) The key breeding sites were ornamental plant pot, buckets, jars, tires and flower pots
Gia Lai province: the rate of adult Ae aegypti collected indoor (95.4%) and outdoor (4.6%), for Ae albopictus the collecting of indoor and outdoor were 12.5% and 87.5% respectively Ae aegypti rest mainly in bed nets (33-53.2%), clothes (30.2%-60.8%) and 0.3% mosquitoes was found resting on the wall Ae albopictus was also found resting on the wall in the rural areas 1 (3.9%) The key breeding sites
were cement tanks, drums, buckets, tires and flower pots
1.3 The dengue virus infection rate of Aedes aegypti and Ae albopictus
Only Ae aegypti samples collected from urban were found infected with dengue virus The dengue virus infection rate of Aedes aegypti and Ae albopictus were 0.82% in Binh Dinh and 0.95% in Gia Lai
2 Susceptibility of Aedes to insecticide
Aedes aegypti and Ae albopictus collected from Binh Dinh and Gia Lai provinces was found resistant to
alphacypermethrin, lambdacyhalothrin, deltamethrin, permethrin However, both of species were still susceptible to malathion
Ae aegypti and Ae albopictus populations from Binh Dinh and Gia Lai provinces were resistant to
lambdacyhalothrin, deltamethrin, permethrin and alphacypermethrin However, both species remained
sensitive to malathion in all the sites of the two provinces
The proportion of samples of Ae aegypti with mutation were 52% in urban areas, 48% in flatlands and 28
in mountainous areas of Binh Dinh and 56% in urban areas, 48% in rural areas 1 and 32% in rural areas 2
of Gia Lai province
Binh Dinh province: Two kdr mutations (L982W and V1016G) in domain II were identified in Ae aegypti populations from urban areas and flatlands, but only found V1016G mutation in the mountainous
Trang 2samples Furthermore, co-occurrence of kdr mutations (L982W and V1016G, 7.7%) appearedin one
same sample of Ae aegypti mosquito in urban In Gia Lai, only kdr mutation L982W (100%) were
detected in all the samples
Promotors
1 Dr Nguyen Xuan Quang
2 Dr Huynh Hong Quang
Hanoi, July 10th, 2019
Ph.D Student
Do Van Nguyen