Studies on african horse sickness virus

Individual cases of african horse sickness were recorded in Upper Egypt during the period startingfrom 21/9/1971 tell 4,3/1972, most samples of thesecases were sent to be suspected ’Jf a post-vaccinationdue to h’Jrse sicID1ess virus vaccines either m’Juse adapted or tissue culture2- Nighteen samples were in’Jculated intracerebrally in baby and adult m ice, only 6 samples Gives ne rv ousaym p’t ome in baby and adult mice. A.s serial passages pr:>gresses the virulence f’:)r m iCE appears t’J increase markedly 1 as indicated oy a Gradual decrease in the ave r ag e time bEtueen injGcti’Jn and death as well asLnc cea s i.ng of titrE o f isolates3- Out of 6 samples .viz., (Edfo1, Aswan 2, Qonn 3, Edfo 4 Qena 5, and El~1’:)hasreen 9) giving symptoms in mice, three ’:)f them, viz., (Edf’:) 1, Aswan 2 and El-Mohagreen 9)showed a cyt’Jpathic effect in tissue culture, wh i.oh appeared 5, 4 and 2 days p’:)stn’:)culati’:)n respectivelyvlith subsequent passage, theincubation period decrease 1 with increasing ’:)f the titres of isolates.