title: Surveillance of the chikungunya vector Aedes albopictus (Skuse) in Emilia-Romagna (northern Italy): organizational and technical aspects of a large scale monitoring system.
abstract: The chikungunya virus outbreak that occurred in 2007 in northern Italy (Emilia-Romagna region) prompted the development of a large scale monitoring system of the population density of Aedes albopictus (Skuse, 1894), comparable at the provincial and municipal levels. In 2007, egg density data presented an aggregated distribution (VMR >1) and Taylor's power law was applied to calculate the minimum number of ovitraps needed to obtain the prefixed precision levels: D=0.2 in the areas where the chikungunya epidemic occurred and D=0.3 in all the other urban areas >600 ha. The estimated minimum ovitrap number was then used to set up a monitoring network at the regional scale in season 2008 (May-October). In 242 municipalities 2,741 ovitraps were activated and the 2008 sampled data showed a similar aggregated distribution as in 2007. The adequacy of the monitoring design was evaluated by recalculating the Taylor's coefficients and the minimum ovitrap number for each urban area >600 ha using the 2008 egg density data. The comparison between the two estimates showed that the minimum ovitrap number calculated in 2007 was underestimated by 2.7% in weeks 22-41 but was overestimated by 29.4% if referring to the period of highest population density (weeks 27-37). The low cost of the proposed monitoring system, based on the use of fortnightly checked ovitraps, could make it economically sustainable even in a non-epidemic season.
authors.affiliation: Medical and Veterinary Entomology, Centro Agricoltura Ambiente G. Nicoli, Crevalcore (BO), Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Carrieri
authors.forename: Alessandro
authors.initials: A
authors.lastname: Albieri
authors.forename: Paola
authors.initials: P
authors.lastname: Angelini
authors.forename: Flavia
authors.initials: F
authors.lastname: Baldacchini
authors.forename: Claudio
authors.initials: C
authors.lastname: Venturelli
authors.forename: Silvia Mascali
authors.initials: SM
authors.lastname: Zeo
authors.forename: Romeo
authors.initials: R
authors.lastname: Bellini
mesh_terms: D000330:Aedes / Q000821:virology*; D000818:Animals; D002646:Chikungunya virus / Q000472:pathogenicity; D007303:Insect Vectors / Q000821:virology*; D007558:Italy; D011156:Population Density