AreAedes albopictusor other mosquito species from northern Italy competent to sustain new arboviral outbreaks?

Abstract

The Asian tiger mosquito Aedes albopictus (Skuse) (Diptera: Culicidae), native to Southeast Asia, has extended its geographical distribution to invade new temperate and tropical regions. This species was introduced in 1990 to Italy and has since become the main pest in urban settings. It was incriminated as a principal vector in the first European outbreak of chikungunya virus (CHIKV) in the province of Ravenna (Italy) in 2007. This outbreak was associated with CHIKV E1-226V, efficiently transmitted by Ae. albopictus. The occurrence of this outbreak in a temperate country led us to estimate the potential of Ae. albopictus to transmit CHIKV and dengue virus (DENV), and to determine the susceptibility to CHIKV of other mosquito species collected in northern Italy. Experimental infections showed that Ae. albopictus exhibited high disseminated infection rates for CHIKV (75.0% in Alessandria; 90.3% in San Lazzaro) and low disseminated infection rates for DENV-2 (14.3% in San Lazzaro; 38.5% in Alessandria). Moreover, Ae. albopictus was able to attain a high level of viral replication, with CHIKV detectable in the salivary glands at day 2 after infection. In addition, the other three mosquito species, Anopheles maculipennis Meigen, Aedes vexans vexans (Meigen) and Culex pipiens L., showed variable susceptibilities to infection with CHIKV, of 0%, 7.7% and 0-33%, respectively. This information on vector competence is crucial in assessing the risk for an outbreak of CHIKV or DENV in Italy.

Experimental studies of susceptibility of Italian Aedes albopictus to Zika virus

“…Finally, ZIKV appears to be less well adapted to the Italian Ae. albopictus than the A226V variant of CHIKV (data not shown), which caused more than 250 cases in Italy after a single introduction from Kerala, India [5,16].…”

Molecular approach for identification of mosquito species (Diptera: Culicidae) in Province of Alessandria, Piedmont, Italy

“…In a recent study, the following dangerous viruses were detected in pooled mosquito samples from N Italy: West Nile virus in C. pipiens, two orthobunya viruses and Tahyna virus in Ochlerotatus caspius and Batai virus in A. maculipennis (Cazolari et al, 2010). Since different species within these complexes can sustain arboviral outbreaks (Talbalaghi et al, 2010), specific diagnosis of the vectors is essential for developing control strategies.…”

Molecular Characterization of the Asian Tiger Mosquito Aedes albopictus (Skuse) (Diptera: Culicidae) in Northern Italy

“…In 2007, it has been incriminated as the main vector of the first European outbreak of chikungunya virus (CHIKV) in northern Italy [2]. A. albopictus from Northern Italy was also demonstrated to efficiently transmit in laboratory CHIKV and to a lesser extent, dengue virus (DENV) [3]. Its expansion all over the world may contribute to obtain a mosaic of genetically distinct populations expressing different abilities to transmit arboviruses [4][5][6][7].…”