Changes

In endemic areas of the United States, around a quarter of referrals for equine neurological disease are attributed to EPM.(22,23 in Furr)  According to the United States Department of Agriculture, the average incidence of the disease is 14 cases per 10,000 horses per year.  However, the challenges of obtaining a definitive diagnosis may mean this figure is an underestimate (Furr).  The disease has been identified in parts of Central and South America, southern Canada and across most of the USA.(Furr) EPM is noted occasionally in other countries, in horses that have been imported from the Americas.(28,29 in Furr).  It is likely that these animals underwent transportation carrying a silent but persistent infection.  There have been reports of EPM in horses that have not travelled to or from endemic regions(Furr), although cross-reacting Ags on the immunoblot test may explain this discrepancy(Furr).   

In endemic areas of the United States, around a quarter of referrals for equine neurological disease are attributed to EPM.(22,23 in Furr)  According to the United States Department of Agriculture, the average incidence of the disease is 14 cases per 10,000 horses per year.  However, the challenges of obtaining a definitive diagnosis may mean this figure is an underestimate (Furr).  The disease has been identified in parts of Central and South America, southern Canada and across most of the USA.(Furr) EPM is noted occasionally in other countries, in horses that have been imported from the Americas.(28,29 in Furr).  It is likely that these animals underwent transportation carrying a silent but persistent infection.  There have been reports of EPM in horses that have not travelled to or from endemic regions(Furr), although cross-reacting Ags on the immunoblot test may explain this discrepancy(Furr).   

The route of infection remains unconfirmed, (Pasq) but there is an increased risk associated with a young age (1-4yrs) (IVIS 3) and autumn months (24 in Furr).  The reported age range for EPM cases is currently 2 months (34 in furr) to 24 years (35 in Furr).  Thoroughbreds, Standardbreds and Quarterhorses are most commonly affected across the US and Canada (30 in Furr).  This may relate to a breed predispostion or alternatively, managemental factors associated with these breeds(32 in Furr).  Showing, racing (25 in Furr) and stress(25 in Furr) have been linked to a greater risk of clinical disease(IVIS 2).  Case clustering may occur where all the risk factors are in operation, most cases appear in isolation (Furr).

The route of infection remains unconfirmed, (Pasq) but there is an increased risk associated with a young age (1-4yrs) (IVIS 3) and autumn months (24 in Furr).  The reported age range for EPM cases is currently 2 months (34 in furr) to 24 years (35 in Furr).  Thoroughbreds, Standardbreds and Quarterhorses are most commonly affected across the US and Canada (30 in Furr).  This may relate to a breed predispostion or alternatively, managemental factors associated with these breeds(32 in Furr).  Showing, racing (25 in Furr) and stress(25 in Furr) have been linked to a greater risk of clinical disease(IVIS 2).   

Increasing age and environmental temperature have been associated with an increased seroprevalence of ''S. neurona''(43 in furr).  Seroprevalence for this species is typically higher than for ''N. hughesi''.(Furr)Other risk factors for EPM include the presence of opossums, rats, mice and woodland, increased population density of humans and horses, bedding horses on shavings or wood chips and the use of purchased grain.(Furr)

Increasing age and environmental temperature have been associated with an increased seroprevalence of ''S. neurona''(43 in furr).  Seroprevalence for this species is typically higher than for ''N. hughesi''.(Furr)Other risk factors for EPM include the presence of opossums, rats, mice and woodland, increased population density of humans and horses, bedding horses on shavings or wood chips and the use of purchased grain.(Furr)Case clustering may operate where all the risk factors occur, but the majority of cases appear in isolation (Furr).

====Life Cycle====

====Life Cycle====