COMPARISON OF THE WHO STANDARD AND THE CDC BOTTLE BIOASSAY TESTING METHODS FOR ASSESSING THE DENGUE VECTORS’ SUSCEPTIBILITY TO INSECTICIDES IN SEMARANG, INDONESIA

Abstract

Dengue hemorrhagic fever (DHF) is a public health concern worldwide, including in Indonesia. Insecticides are the most common method to control dengue vectors. The massive use of insecticides increases the risk of resistance. The World Health Organization (WHO) impregnated paper method has been used to evaluate insecticides for decades. Since 2019, Indonesia has used the Centers for Disease Control and Prevention (CDC) bottle bioassay method in testing resistance. This study aimed to compare resistance tests conducted using the CDC and the WHO methods. Larvae of Aedes aegypti were collected from three villages in Semarang City. As a comparison, the Ae. aegypti colony captured in 1986 in Semarang City was used. Insecticides evaluated included pyrethroids cypermethrin and organophosphate malathion. Synergist piperonyl butoxide (PBO) was used to determine the resistance mechanism. The Voltage-Gated Sodium Channels (VGSC) and ACE1 genes were sequenced as part of the molecular assays. Data from the WHO and the CDC methods showed that Ae. aegypti from all locations were resistant to cypermethrin and revealed different results for malathion. Using the WHO method, the test mosquitoes showed resistance but indicated susceptibility when using the CDC method. Metabolic and target site mutations were discovered as resistance mechanisms to cypermethrin. Further research and regulation are needed to implement both approaches to monitor resistance.