Latin America – Dengue: dimensions of vector breeding in five urban settings

RESEARCH ARTICLE Open Access
Ecological, biological and social dimensions of
dengue vector breeding in five urban settings of
Latin America: a multi-country study
Juliana Quintero and others

Abstract
Background:
Dengue is an increasingly important public health problem in most Latin American countries and
more cost-effective ways of reducing dengue vector densities to prevent transmission are in demand by vector
control programs. This multi-centre study attempted to identify key factors associated with vector breeding and
development as a basis for improving targeted intervention strategies.
Methods:
In each of 5 participant cities in Mexico, Colombia, Ecuador, Brazil and Uruguay, 20 clusters were
randomly selected by grid sampling to incorporate 100 contiguous households, non-residential private buildings
(businesses) and public spaces. Standardized household surveys, cluster background surveys and entomological
surveys specifically targeted to obtain pupal indices for
Aedes aegypti
, were conducted in the dry and wet seasons.
Results:
The study clusters included mainly urban low-middle class populations with satisfactory infrastructure
and
–
except for Uruguay- favourable climatic conditions for dengue vector development. Household knowledge
about dengue and
“
dengue mosquitoes
”
was widespread, mainly through mass media, but there was less
awareness around interventions to reduce vector densities. Vector production (measured through pupal indices)
was favoured when water containers were outdoor, uncovered, unused (even in Colombia and Ecuador where
the large tanks used for household water storage and washing were predominantly productive) and
–
particularly
during the dry season- rainwater filled. Larval infestation did not reflect productive container types. All productive
container types, including those important in the dry season, were identified by pupal surveys executed during
the rainy season.
Conclusions:
A number of findings are relevant for improving vector control: 1) there is a need for complementing
larval surveys with occasional pupal surveys (to be conducted during the wet season) for identifying and
subsequently targeting productive container types; 2) the need to raise public awareness about useful and effective
interventions in productive container types specific to their area; and 3) the motivation for control services
that-according to this and similar studies in Asia- dedicated, targeted vector management can make a difference in
terms of reducing vector abundance.
Keywords:
Dengue,
Aedes aegypti
, Vector breeding sites, Pupal indices, Urban settings, Ecobiosocial framework Read Article