Epsilon Archive for Student Projects

Abstract

West Nile Fever and West Nile Encephalitis are caused by the flavivirus West Nile Virus (WNV). West Nile Virus is now a dangerous threat for horses, birds and humans.

WNV is spread mainly between mosquitoes and birds, but can infect humans and animals when mosquitoes change targets. Mosquitoes prefer some bird species and in lack off those, the risk that the mosquitoes will infect humans increases.

Some bird species are more effective hosts for the virus, and the rate of virus spread depends on the vector species too. In the US, the mosquito Culex pipiens (which can also be found in Sweden) is considered the primary vector of WNV.

The virus concentration in the mosquitoes depends on the temperature, and a warmer climate may affect the spread of WNV in EU. Climate changes may also cause changes in bird- and vector life. Antibodies against WNV have been found in migrating birds in Northern Europe, and the connection between disease and migrating birds has been discussed.

To estimate if WNV can spread in and to Northern Europe, the interaction between mosquitoes and birds, as well as their individual impact, is investigated. Climate change among other factors affecting mosquitoes and birds, and thus indirectly the spread of WNV, is also covered.

It is said that it is possible that WNV may come to Northern Europe and Sweden in the future. However, further investigations have to be done to better understand the dynamics of WNV in Northern Europe.