Changes

===Transmission===

===Transmission===

Transfer is '''vector'''-mediated, primarily via '''[[Culicidae|mosquito]] salivary transfer'''.  WEE and VEE may also be transmitted horse to horse through nasal secretions.  This mode of transmission is less likely, despite the fact that high concentrations of VEE virus are found in ocular and nasal discharges from infected horses.<ref>Kissling, R.E, Chamberlain, R.W (1967) Venezuelan equine encephalitis, ''Adv Vet Sci Comp Med'', 11:65-84.  In: Bertone, J.J (2010) Viral Encephalitis in Reed, S.M, Bayly, W.M. and Sellon, D.C (2010) '''Equine Internal Medicine''' (Third Edition), ''Saunders'', Chapter 12</ref>  The viraemic phase ends when nervous signs develop<ref name="multiple">Bertone, J.J (2010) Viral Encephalitis in Reed, S.M, Bayly, W.M. and Sellon, D.C (2010) '''Equine Internal Medicine''' (Third Edition), ''Saunders'', Chapter 12</ref> and is important for disease amplification.  Amplification from horses is likely only with VEE virus, in association with a relatively high and potentially persistent viraemia.<ref name="again">Merck & Co (2008) The Merck Veterinary Manual (Eighth Edition), Merial found at http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/100900.htm&word=Equine%2cencephalitis, accessed July 2010</ref>  Similarly, zoonotic spread is unlikely for Eastern and Western equine encephalitis, but has been noted with VEE.

Transfer is '''vector'''-mediated, primarily via '''[[Culicidae|mosquito]]''' salivary transfer.  WEE and VEE may also be transmitted horse to horse through nasal secretions.  This mode of transmission is less likely, despite the fact that high concentrations of VEE virus are found in ocular and nasal discharges from infected horses.<ref>Kissling, R.E, Chamberlain, R.W (1967) Venezuelan equine encephalitis, ''Adv Vet Sci Comp Med'', 11:65-84.  In: Bertone, J.J (2010) Viral Encephalitis in Reed, S.M, Bayly, W.M. and Sellon, D.C (2010) '''Equine Internal Medicine''' (Third Edition), ''Saunders'', Chapter 12</ref>  The viraemic phase ends when nervous signs develop<ref name="multiple">Bertone, J.J (2010) Viral Encephalitis in Reed, S.M, Bayly, W.M. and Sellon, D.C (2010) '''Equine Internal Medicine''' (Third Edition), ''Saunders'', Chapter 12</ref> and is important for disease amplification.  Amplification from horses is likely only with VEE virus, in association with a relatively high and potentially persistent viraemia.<ref name="again">Merck & Co (2008) The Merck Veterinary Manual (Eighth Edition), Merial found at http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/100900.htm&word=Equine%2cencephalitis, accessed July 2010</ref>  Similarly, zoonotic spread is unlikely for Eastern and Western equine encephalitis, but has been noted with VEE.

===Seasonal Incidence===

===Seasonal Incidence===