Establishment of Wolbachia Strain wAlbB in Malaysian Populations of Aedes aegypti for Dengue Control

Vector control using insecticide is a major effort to control Dengue Haemorrhagic Fever. The excessive use of insecticides leads to insecticide resistance in Aedes aegypti. This study aimed to determine the resistance status of Aedes aegypti in North Sumatra and Jambi Province to malathion, deltametrin, cypermethrin, lambda cyhalothrin and alpha cypermethrin. A cross sectional study was conducted during 2015, the research location covers North Sumatera area (Tebing Tinggi, Deli Serdang, and Pematang Siantar) and Jambi (Muaro Jambi, Jambi, and Batang Hari). Susceptibility test using WHO kits was applied on F1 generation and interview with Local Public Health Officer was carried out to obtain information about the usage of insecticide in both provinces. Resistance to malathion, cypermethrin, and lambda cyhaltorhin was observed in Ae. aegypti populations from all study area. Tolerant status to deltamethrin only found in Aedes aegypti from Deli Serdang, whilst the other strains were resistant. Ae. aegypti population from all study area were tolerant to alpha cypermethrin. Malathion and cypermethrin were the only insecticide ever used in both provinces. We conclude that alpha cypermethrin was effective to combat Ae. aegypti and can be used as an alternative insecticide for dengue control program in Northern Sumatera and Jambi Province.

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Wolbachia-mediated sterility suppresses Aedes aegypti populations in the urban tropics

10.1101/2021.06.16.21257922 ◽

2021 ◽

Author(s):

◽

Lee Ching Ng

Keyword(s):

Aedes Aegypti ◽

Vertical Distribution ◽

High Rise ◽

Promising Tool ◽

Incompatible Insect Technique ◽

Tropical Cities ◽

Dengue Control ◽

Housing Estates

Incompatible insect technique (IIT) via releases of male Wolbachia-infected mosquitoes is a promising tool for dengue control. In a three-year trial in Singaporean high-rise housing estates, we demonstrated that Wolbachia-based IIT dramatically reduces both wildtype Aedes aegypti populations [reductions of 92.7% (95% CI: 84.7%-95.8%) and 98.3% (97.7%-99.8%)] and dengue incidence [reductions of 71% (43%-87%) to 88% (57%-99%)] in the targeted areas. The study highlights the need to ensure adequate vertical distribution of released males in high-rise buildings, address immigration of wildtype females from neighboring areas, and prevent and mitigate stable establishment of Wolbachia in field mosquito populations. Our results demonstrate the potential of Wolbachia-based IIT (supplemented with irradiation, in Singapore's context) for strengthening dengue control in tropical cities, where dengue burden is the greatest.

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Persistence of malathion used in dengue control on household surfaces

Arquivos do Instituto Biológico ◽

10.1590/1808-1657000042018 ◽

2019 ◽

Vol 86 ◽

Author(s):

Regina Cristina Batista Ferreira ◽

Solange Papini ◽

Luiz Carlos Luchini ◽

Eliane Vieira

Keyword(s):

Gas Chromatography ◽

Aedes Aegypti ◽

Viral Infection ◽

Vegetable Oil ◽

Liquid Scintillation ◽

Soil Samples ◽

Porous Surfaces ◽

Dengue Control

ABSTRACT: Dengue is a viral infection transmitted by the mosquito Aedes aegypti. In Brazil, one of the insecticides used to control the mosquito is malathion, which can be diluted in vegetable oil (1:2 v/v). The purpose of this study was to understand the persistence of malathion on different surfaces and soil. Surfaces were contaminated by malathion and then washed with water and soap. The water used to clean the surfaces was extracted and analyzed by gas chromatography with an FID detector. Soil samples received malathion 14C-TG diluted in vegetable oil (1:2 v/v) and were analyzed zero, 3, 7, 18, 32, 60, 120, 240, and 360 days after the application in a liquid scintillation analyzer. Results showed a high persistence of malathion on porous surfaces. Moreover, it did not degrade in the soil for the first 120 days.

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Baseline data on the bionomics of Aedes aegypti to support dengue control strategies in Burkina Faso

International Journal of Infectious Diseases ◽

10.1016/j.ijid.2018.11.052 ◽

2019 ◽

Vol 79 ◽

pp. 14

Author(s):

A. Badolo ◽

A. Sombie ◽

P. Pignatelli ◽

F. Yaméogo ◽

A. Sanon ◽

...

Keyword(s):

Aedes Aegypti ◽

Burkina Faso ◽

Control Strategies ◽

Baseline Data ◽

Dengue Control

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Spatial Clustering of Aedes aegypti Related to Breeding Container Characteristics in Coastal Ecuador: Implications for Dengue Control

American Journal of Tropical Medicine and Hygiene ◽

10.4269/ajtmh.12-0485 ◽

2013 ◽

Vol 89 (4) ◽

pp. 758-765 ◽

Cited By ~ 15

Author(s):

Nathaniel H. Schafrick ◽

Joseph N. S. Eisenberg ◽

Meghan O. Milbrath ◽

Veronica J. Berrocal ◽

Mark L. Wilson

Keyword(s):

Aedes Aegypti ◽

Spatial Clustering ◽

Dengue Control

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Infestation measured by Aedes aegypti larval surveys as an indication of future dengue epidemics: an evaluation for Brazil

Transactions of the Royal Society of Tropical Medicine and Hygiene ◽

10.1093/trstmh/traa021 ◽

2020 ◽

Vol 114 (7) ◽

pp. 506-512

Author(s):

Andrew W Enslen ◽

Antonio S Lima Neto ◽

Marcia C Castro

Keyword(s):

Resource Allocation ◽

Aedes Aegypti ◽

Present Form ◽

Classification Analysis ◽

Predictive Values ◽

Control Programs ◽

The North ◽

Larval Survey ◽

Dengue Control ◽

Dengue Epidemics

Abstract Background Aedes aegypti rapid larval surveys are mandatory in Brazil. Here, we retrospectively examined whether the house index estimated by larval surveys served as a useful tool in anticipating epidemics within Brazilian municipalities from 2009–2015. Methods We used correlation indices and classification analysis stratified by year, region, population size and time after the national larval survey. Results We found no association between the house index and the proportion of municipalities experiencing an epidemic. The sensitivity of a high score house index in predicting an epidemic was 7.20% (95% CI 6.22 to 8.33%) for all years combined. The positive predictive value of a high score house index to predict a ‘true epidemic’ was 38.96%, lower than the negative predictive values of a low score house index for predicting ‘no epidemic’ (56.96%). The highest overall sensitivity was observed in the North region (20.15%; 95% CI 17.14 to 23.53%). The sensitivity of a high score house index demonstrated a monotonic decrease with increasing time from larval collection. Conclusions Larval surveys are surveillance tools with the potential to risk-stratify and guide dengue control programs towards judicious resource allocation. However, the national rapid larval survey performed in Brazil, in its present form, consistently underpredicts dengue epidemics.

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