NEW PROACTIVE PARADIGM FOR DENGUE SURVEILLANCE USING GOD TRAPS AND NS1 KITS

Abstract

Dengue continues to be a major public health problem in many parts of the world. Vector control is the hallmark of dengue control programme in most countries in Southeast Asia. However, it is known that the current program lacks sensitivity and proactivity. It is also known that asymptomatic people are infectious to mosquitoes and this could be a reason for increase in cases with current ongoing surveillance measures. A randomised control trial was conducted to determine the efficacy of a combination of gravid oviposition sticky (GOS) traps and dengue non-structural 1 (NS1) antigen for early surveillance of dengue among Aedes mosquitoes. GOS traps were set weekly at the intervention apartments to trap the Aedes mosquitoes and these were tested with NS1 antigen kits. Dengue cases in the intervention arm were less than the control arm. Detection of NS1 positive mosquitoes were significantly associated with GOS Aedes index (rs= 0.68 P<0.01) and occurrence of dengue cases (rs=0.31 P<0.01). The result of this randomized control trial further supports the notion that dengue surveillance using GOS trap and dengue NS1 test can detect dengue-positive mosquitoes before dengue cases were reported. Moreover, the significant positive correlation of dengue cases with the number of NS1 positive mosquito pool shows detection of dengue positive mosquito can be used as an indicator of viral transmission. To the best of our knowledge, this is the first study that demonstrates a dengue surveillance system which is able to capture asymptomatic, dengue-viraemic individuals living in an area with infected mosquitoes. In conclusion infected Aedes mosquitoes can serve as an early warning and identification of such mosquitoes should be the way forward for proactive dengue surveillance and control measures.