Specimens had been screened as appropriate for poisons and specific pathogens, including rabies, equine herpes virus, African horse sickness virus, and equine encephalosis virus (4,5).
Most cases were identified in the autumn and winter months, which overlap with African horse sickeness, equine encephalosis, and West Nile virus outbreaks in South Africa (5,15), which have similar clinical signs.
From October 2008 through January 2009, a febrile horse disease that was diagnosed as equine encephalosis was observed in dozens of stables across Israel (7).
Equine encephalosis virus has long been enzootic to southern Africa, but it has not been isolated in other parts of the world.
African horse sickness virus (AHSV), equine encephalosis
virus (EEV), and equine herpesviruses (EHV) 1 and 4 were identified by using viral culture and antigen detection assays and/or complement fixation tests (31) on serum samples and using RT-PCR to detect AHSV and EHV (32).