Disease-bearing insects brought in by international aircraft into Singapore

Fifty-seven (17.3%) of 330 incoming aircraft landing at Changi International Airport were found to harbour mosquitoes and other insects on board. The frequency of insects detected in aircraft from the Southeast Asian countries varied from 7.1% to 32.2%. Live insects were found in 5 (6.1%) of 82 aircraft disinsectized by the "block away" method. The species of mosquitoes brought in were: Culex quinquefasciatus (96), Culex tritaeniorhynchus (1), Aedes albopictus (2) and Aedes aegypti (1). None of the 51 female Culex quinquefasciatus dissected was found to be infected with microfilariae. They key to the prevention of introduction of exotic vectors and transmission of vector- borne diseases is to continue with the existing system of vector surveillance and control at the international airport, rather than routine disinsecting of aircraft landing in Singapore.