Browsing by Author "Medlock, J.M."
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- Detection of mosquito-only flaviviruses in EuropePublication . Calzolari, M.; Zé-Zé, Líbia; Ruzek, D.; Vazquez, A.; Jeffries, C.; Defilippo, F.; Osório, Hugo Costa; Kilian, P.; Ruíz, S.; Fooks, A.R.; Maioli, G.; Amaro, Fátima; Tlusty, M.; Figuerola, J.; Medlock, J.M.; Bonilauri, P.; Alves, M.J.; Sebesta, O,; Tenorio, A.; Vaux, A.G.; Bellini, R.; Gelbic, I.; Sánchez-Seco, M.P.; Johnson, N.; Dottori, M.The genus Flavivirus, family Flaviviridae, includes a number of important arthropod-transmitted human pathogens such as dengue viruses, West Nile virus, Japanese encephalitis virus and yellow fever virus. In addition, the genus includes flaviviruses without a known vertebrate reservoir, which have been detected only in insects, particularly in mosquitoes, such as cell fusing agent virus, Kamiti River virus, Culex flavivirus, Aedes flavivirus, Quang Binh virus, Nakiwogo virus and Calbertado virus. Reports of the detection of these viruses with no recognized pathogenic role in humans are increasing in mosquitoes collected around the world, particularly in those sampled in entomological surveys targeting pathogenic flaviviruses. The presence of six potential flaviviruses, detected from independent European arbovirus surveys undertaken in the Czech Republic, Italy,Portugal, Spain and the UK between 2007 and 2010, is reported in this work. Whilst the Aedes flaviviruses, detected in Italy from Aedes albopictus mosquitoes, had already been isolated in Japan, the remaining five viruses have not been reported previously: one was detected in Italy, Portugal and Spain from Aedes mosquitoes (particularly from Aedes caspius), one in Portugal and Spain from Culex theileri mosquitoes, one in the Czech Republic and Italy from Aedes vexans, one in the Czech Republic from Aedes vexans and the last in the UK from Aedes cinereus. Phylogenetic analysis confirmed the close relationship of these putative viruses to other insect-only flaviviruses.
- Driving forces for changes in geographical distribution of Ixodes ricinus ticks in EuropePublication . Medlock, J.M.; Hansford, K.M.; Bormane, A.; Derdakova, M.; Estrada-Peña, A.; George, J-C; Golovljova, I.; Jaenson, T.G.; Jensen, J-K; Jensen, P.M.; Kazimirova, M.; Oteo, J.A.; Papa, A.; Pfister, K.; Plantard, O.; Randolph, S.E.; Rizzoli, A.; Santos-Silva, M.M.; Sprong, H.; Vial, L.; Hendrickx, G.; Zeller, H.; Van Bortel, W.Many factors are involved in determining the latitudinal and altitudinal spread of the important tick vector Ixodes ricinus (Acari: Ixodidae) in Europe, as well as in changes in the distribution within its prior endemic zones. This paper builds on published literature and unpublished expert opinion from the VBORNET network with the aim of reviewing the evidence for these changes in Europe and discusses the many climatic, ecological, landscape and anthropogenic drivers. These can be divided into those directly related to climatic change, contributing to an expansion in the tick's geographic range at extremes of altitude in central Europe, and at extremes of latitude in Scandinavia; those related to changes in the distribution of tick hosts, particularly roe deer and other cervids; other ecological changes such as habitat connectivity and changes in land management; and finally, anthropogenically induced changes. These factors are strongly interlinked and often not well quantified. Although a change in climate plays an important role in certain geographic regions, for much of Europe it is non-climatic factors that are becoming increasingly important. How we manage habitats on a landscape scale, and the changes in the distribution and abundance of tick hosts are important considerations during our assessment and management of the public health risks associated with ticks and tick-borne disease issues in 21st century Europe. Better understanding and mapping of the spread of I. ricinus (and changes in its abundance) is, however, essential to assess the risk of the spread of infections transmitted by this vector species. Enhanced tick surveillance with harmonized approaches for comparison of data enabling the follow-up of trends at EU level will improve the messages on risk related to tick-borne diseases to policy makers, other stake holders and to the general public.
- Importation of a Hyalomma lusitanicum tick into the UK on a dogPublication . Hansford, K.M.; Medlock, J.M.; Atkinson, B.; Santos-Silva, M.M.A SINGLE, fully engorged female Hyalomma lusitanicum tick was imported into the UK on a dog recently returned from Portugal during May 2016 and submitted to Public Health England's Tick Surveillance Scheme (TSS). H lusitanicum exists in a narrow geographical range from Portugal to Sicily (Estrada-Peña and others 2012), where its distribution is restricted due to its strict biotic niche (Estrada-Peña and Venzal 2007). Immature stages parasitise wildlife (Santos-Silva and others 2011) and adults are mostly associated with domestic and wild ungulates (Valcárcel and others 2015). However, records on dogs have been reported (Apanaskevich and others 2008), including in Portugal where biting of humans by this species has also been reported (Santos-Silva and others 2011)… (…)