Benefit Evaluation of Dengue Adult Mosquito Chemical Control and Its Application
2009 Vol.25 NO.6
Correspondence Author： Jen-Hsin Wang,
In Southeast Asia, most countries use insecticide spray to kill adult mosquitoes as a major way of prevention of dengue fever. However, literature review and studies in Asia, Central and South America, and Caribbean area, have shown that the effectiveness of this method targeting adult mosquitoes for prevention of dengue fever is very limited. Effectiveness of insecticide spray is also affected by the spraying equipments, maintenance of the equipments, correct dilution of insecticides, and resistance of mosquitoes. In addition, labor and budgets required for spraying insecticide form a big burden for health authorities. Hence many countries recently have reassessed and modified methods of spraying insecticides. It has been suggested that spraying is only applied when and where appropriate, in addition to eradication of breeding source, elimination of larvae, and personal prevention. Indications for insecticide spraying include cluster infections (more than two cases within 150 meters radius in 14 days), occurring of more than two serotypes of dengue viruses, and appearance of dengue hemorrhagic fever.Insecticide spraying to prevent dengue fever has been used in Taiwan for more than 20 years. It is usually done immediately when suspected cases are reported. However, outbreaks of dengue fever still occur every year. Since local counties or cities apply insecticide indoors by the thermal fogging method that leads to wet floor surface, complaint and resistance of residents increase gradually. As rapid testing reagents are getting popular, it is time to reassess timing and methods of chemical spraying for prevention and control of dengue fever. Recommendations of WHO and experience of other countries can be used as a reference in our strategy for prevention of dengue fever and control of adult mosquitoes.
Keywords: Aedes aegypti, insecticide spraying, space spray, ultra low-volume, chemical control of adult mosquitoes