Habitat characteristics that favour the presence of Aedes aegypti (Diptera: Culicidae) in households in the city of Córdoba, a temperate area of Argentina

TL;DR

This study identifies household container features and environmental conditions in Córdoba, Argentina, that support the breeding of Aedes aegypti mosquitoes, which transmit diseases like dengue.

Contribution

The study reveals how microenvironmental factors and container characteristics influence Aedes aegypti presence in a temperate region.

Findings

Small plastic containers and shaded vegetation increase Aedes aegypti presence.

Precipitation and higher minimum temperatures correlate with higher mosquito abundance.

Abandoned containers like tarpaulins serve as breeding sites during cold and dry seasons.

Abstract

Aedes aegypti is the vector of dengue fever and chikungunya in the city of Córdoba, Argentina, a city situated at the southern limit of disease transmission by the vector in a temperate area. This study aims to characterise the habitat of juvenile Ae. aegypti in households and assess the influence of microenvironmental and environmental variables on its occurrence.

Monthly surveys were conducted from 2019 to 2020 and in 2021 in peridomiciles. Water containers where Ae. aegypti were found were classified according to their material, class and capacity. Using generalised linear mixed models, we evaluated the influence of surrounding vegetation, water container availability and weather conditions (air temperature and precipitation during autumn, summer and spring) on the presence and abundance of juvenile Ae. aegypti.

Of the 689 containers surveyed, 109—found in 36.7% (77/210) of the households—contained juvenile Ae. aegypti. Small (1–8 l) and very small (< 0.5 l) containers accounted for 80.4% of the containers positive for juvenile Ae. aegypti, with plastic jars being the most common. Vases and tarpaulins/plastic covers were the most productive containers. Containers shaded by vegetation were 2.5-fold more likely to harbour juveniles than those exposed to sunlight or artificial shade. The strong interaction between tree cover and shade provided by vegetation suggested that vegetation cover enhances mosquito abundance. Juvenile abundance increased with container capacity, while higher precipitation and minimum temperature in the previous weeks also favoured the presence of juveniles.

Household containers, which are widely available and diverse in size and material in Córdoba City, provide favourable conditions for the persistence of Ae. aegypti. Abandoned nonfunctional and cryptic sites, such as tarpaulins and plastic covers, can provide breeding sites that enable Ae. aegypti mosquitoes endure the cold and dry seasons. During the warm and wet seasons, the presence and abundance of Ae. aegypti are influenced by microenvironmental conditions, such as shade provided by vegetation, high minimum temperatures and precipitation. The variety and number of available containers, together with shelter and feeding conditions, suggest that female mosquitoes can still find breeding sites even after selective household control measures have been implemented. These results, supported by generalised linear mixed models, which consider the lack of independence between containers within the same household or block, highlight the importance of incorporating fine-scale environmental variables into vector control planning.

The online version contains supplementary material available at 10.1186/s13071-025-07114-1.

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