Eco-bio-social determinants of dengue vector breeding: a multicountry study in urban and periurban Asia.
OBJECTIVE
To study dengue vector breeding patterns under a variety of conditions in public and private spaces; to explore the ecological, biological and social (eco-bio-social) factors involved in vector breeding and viral transmission, and to define the main implications for vector control.


METHODS
In each of six Asian cities or periurban areas, a team randomly selected urban clusters for conducting standardized household surveys, neighbourhood background surveys and entomological surveys. They collected information on vector breeding sites, people's knowledge, attitudes and practices surrounding dengue, and the characteristics of the study areas. All premises were inspected; larval indices were used to quantify vector breeding sites, and pupal counts were used to identify productive water container types and as a proxy measure for adult vector abundance.


RESULTS
The most productive vector breeding sites were outdoor water containers, particularly if uncovered, beneath shrubbery and unused for at least one week. Peridomestic and intradomestic areas were much more important for pupal production than commercial and public spaces other than schools and religious facilities. A complex but non-significant association was found between water supply and pupal counts, and lack of waste disposal services was associated with higher vector abundance in only one site. Greater knowledge about dengue and its transmission was associated with lower mosquito breeding and production. Vector control measures (mainly larviciding in one site) substantially reduced larval and pupal counts and "pushed" mosquito breeding to alternative containers.


CONCLUSIONS
Vector breeding and the production of adult Aedes aegypti are influenced by a complex interplay of factors. Thus, to achieve effective vector management, a public health response beyond routine larviciding or focal spraying is essential.
Arunachalam
Natarajan
N
Centre for Research in Medical Entomology, Indian Council of Medical Research, Madurai, TN, India. crmeicmr@icmr.org.in
Tana
Susilowati
S
Espino
Fe
F
Kittayapong
Pattamaporn
P
Abeyewickreme
Wimal
W
Wai
Khin Thet
KT
Tyagi
Brij Kishore
BK
Kroeger
Axel
A
Sommerfeld
Johannes
J
Petzold
Max
M
D000818:Animals; D001208:Asia; D003625:Data Collection; D003715:Dengue / Q000635:transmission; D004197:Disease Reservoirs / Q000469:parasitology; D017753:Ecosystem; D007303:Insect Vectors; D009032:Mosquito Control; D018881:Suburban Health; D014504:Urban Health