The spatio-temporal characteristics of potential dengue risk assessed by Aedes aegypti and Aedes albopictus in high-epidemic areas

Abstract

Aedes aegypti (AE) and Aedes albopictus (AA) are the two major dengue vectors in the world. To control dengue, monitoring vectors is essential. The abundance and distribution of mosquitoes are usually considered as a proxy for dengue outbreaks. Most of the researches catch the abundance and distribution of vectors by using traps, but this kind of information only can reflect partial relationship between the mosquitoes and dengue since human factors were not taken into account. To have a better proxy for dengue risk, this research evaluated the spatiotemporal distribution of dengue vectors by a human population-stratified ovitrap survey. We demonstrated the potential intensity of dengue transmission spatio-temporally in the high epidemic areas. We analyzed the temporal patterns of vector abundances, compared the levels of vector aggregation indoors with outdoors, and assess the vector concentration tendency around residential centers and administration edges form June 2010 to June 2011. We found significantly more AA outdoors than indoors, and no matter outdoor or indoor settings were, the abundances of AA were descending from the pre-epidemic period to post-epidemic period. AE also had the descending pattern, but there were no significant differences detected between outdoor and indoor settings. AA hotspots appeared almost the same locations from the pre-epidemic period to post-epidemic period, but no obvious repetitive AE hotspots were shown. We also found that AA tended to aggregate around the residential centers while AE likely clustered around the district boundaries. Our study concluded these spatio-temporal characteristics of AE and AA addressed from a population adjusted ovitrap method implied the risks of dengue in different times and locations. To more efficiently control dengue, except for routine unspecific control interventions, the authorities should realize different environmental management strategies were needed for AE and AA.