Detection and monitoring of mosquito flaviviruses in Spain between 2001 and 2005.

Between the years 2001 and 2005, a total of 72,895 female mosquitoes were trapped during their season of abundance, and analyzed. They were sorted into 4,723 pools belonging to 20 Culicidae species from the Anopheles, Aedes, Ochlerotatus, Culex, Culiseta, Coquillettidia, and Uranotaenia genera. The aim was to detect arboviral RNA directly from mosquito homogenates for the genera Alphavirus, Flavivirus, and Phlebovirus. The study formed part of general arbovirus transmission research in four of the most important wetlands in Spain; in the provinces of Girona, Barcelona, Tarragona, and Huelva. The mosquitoes were collected using human bait, CO(2) traps, or light traps, and they were pooled according to date of collection, location, and species. No arboviral RNA from known pathogenic arboviruses was found. However, 111 pools tested positive for unknown mosquito Flavivirus, the only genus detected. The Flavivirus sequences identified were different from all known Flavivirus mosquito viruses, but very close to Kamiti River virus or cell fusing agent virus. The maximum likelihood estimation infection rate (MLE) was calculated for all regions and species. Aedes albopictus had the highest MLE at 47.14, followed by Ae. vexans with 43.67 (over the entire area). These species were followed by Culiseta annulata, with 36.00. The most common species, Ochlerotatus caspius and Culex pipiens, had low MLE values-0.94 and 0.38, respectively-over the area as a whole.

A survey of mosquitoes breeding in used tires in Spain for the detection of imported potential vector species.

The used tire trade has facilitated the introduction, spread, and establishment of the Asian tiger mosquito, Aedes albopictus, and other mosquito species in several countries of America, Africa, Oceania, and Europe. A strategy for detecting these imported mosquito vectors was developed in Spain during 2003-2004 by EVITAR (multidisciplinary network for the study of viruses transmitted by arthropods and rodents). A survey in 45 locations found no invasive species. Eight autochthonous species of mosquitoes were detected in used tires, including Culex pipiens, Cx. hortensis, Cx. modestus, Anopheles atroparvus, An. claviger, Culiseta longiareolata, Cs. annulata, and Aedes caspius. Dominant species were Cx. pipiens and Cs. longiareolata. Aedes caspius was found in only once, near its natural breeding habitat. Considering the recent discovery of an established population of Ae. albopictus in Catalonia, the increasing commerce of used tires in Spain for recycling, storage, and recapping might greatly contribute to the rapid spread of this species across the Iberian Peninsula.

Results of current surveillance of likely bluetongue virus vectors of the genus Culicoides in Catalonia, Spain.

Following the outbreaks of bluetongue (BT) disease in sheep on the Balearic islands in 2000, a survey was conducted for Culicoides vectors along the eastern Catalonian cost of continental Spain where the presence of only C. obsoletus (Meigen) and C. pulicaris (Linnaeus) was known. Light-trap collections made at eight sites in 2002 yielded nine species of Culicoides, including C. imicola Kieffer (represented by a gravid female caught at Dosrius at a latitude of 41 degrees 35'N) and C. scoticus Downs and Kettle. The following season (2003), C. imicola was captured consistently at all sites and in greater numbers (maximum catch of 46) from August to November. The findings suggest that the distribution of C. imicola is extending northwards into Europe. The presence of four bluetongue vectors (C. imicola, C. obsoletus, C. pulicaris and C. scoticus) in Catalonia is of concern.