Relevance of differentiating between residential and non-residential premises for surveillance and control of Aedes aegypti in Rio de Janeiro, Brazil

Entomological surveys on Aedes aegypti (L.) often focus on residential premises, while ignoring non-residential premises. It has been proposed that the latter should be subject to specific monitoring strategies, since they have the potential to contribute a large proportion of the overall mosquito population. In this study, we used traps for ovipositing females to compare the levels of Ae. aegypti infestation in residential and non-residential premises and assess whether there was any evidence for a spatial association of infestation between non-residential premises and the surrounding homes. This information is important for designing specific surveillance programmes for these special sites and their surroundings. This study was conducted in three neighbourhoods of the city of Rio de Janeiro, Brazil, with distinct population densities, water services, dengue histories and vegetation coverage. Ae. aegypti abundance was measured using two types of traps (standard and sticky ovitraps) installed in five non-residential premises and 80 residential premises per neighbourhood. Mosquitoes were collected in the summer (January to March) and winter (June to September) of 2007. The distribution of captures per household per week did not differ significantly between the seasons, although larger numbers of eggs and adults were obtained during the summer. Most non-residential premises were not significantly more infested than homes, despite the larger quantities of containers. There were a few exceptions, including a transportation company, two recycling centres and a boat yard. These highly infested non-residential premises were also spatially associated with highly infested homes in the vicinity. Continuous monitoring with traps may be an effective way of evaluating non-residential premises as sources of dengue vectors for nearby communities.