The outbreak was formally reported to the International Organisation for Animal Health on July 31 by veterinary official Dr Hamid Abd El-Tawab Samaha.
The outbreak was confirmed on July 10. The notifiable disease has not occurred in Eqypt since 1989.
The outbreak is reportedly in racehorses in Al Qahirah (Heliopolis) and in another group at Al Jazah.
Fifty-seven cases have so far been reported and 2280 horses are said to be at risk of infection. No horses have so far died in the outbreak.
Affected areas have been quarantined and disinfection protocols have been introduced.
Meanwhile, authorities in northern India believe they have contained an outbreak centred on the Baltal area, with movement restrictions playing a key part in its containment.
The outbreak affected various villages and communities in the Kashmir region, with one community having 130 of 150 horses fall ill.
There were initially concerns about the wide use of ponies - up to 11,000 - to traditionally transport pilgrims during a recent religious celebration, but restrictions on affected areas managed to keep it contained.
Authorities also set up mobile facilities to provide veterinary treatment for any equines in need, in some cases performing minor surgical procedures.
Equines remain a key part of the economy in the region, being used to carry people and goods.