H. Elhasnaoui et al., SEROLOGICAL AND VIROLOGICAL RESPONSES IN MULES AND DONKEYS FOLLOWING INOCULATION WITH AFRICAN HORSE SICKNESS VIRUS SEROTYPE-4, Archives of virology, 1998, pp. 29-36
Two groups, comprising 4 donkeys and 4 mules (group 1) and 4 donkeys a
nd 3 mules (group 2), were used to determine the duration of viraemia
and to monitor the development of antibodies following inoculation wit
h African horse sickness virus (AHSV). One group of animals was given
a single dose of attenuated AHSV serotype 4 (AHSV 4) vaccine. The seco
nd group was inoculated with a virulent field strain of AHSV 4. Both g
roups were subsequently challenged with the virulent field strain of A
HSV 4, 51 and 58 days, respectively, after their primary inoculation.
Blood and serum samples, collected on alternate days after the primary
inoculations and also after subsequent challenge, were assayed for vi
rus and antibodies. Seven of the 8 AHSV vaccinated (group 1) and 7 of
the 7 AHSV inoculated (group 2) animals showed humoral antibody respon
ses after primary inoculation. Although no infectious virus could be i
solated from either group for the duration of the study, reverse trans
cription-PCR data obtained for the second group did show the presence
of AHSV viral RNA from as early as day 5 in mules and day 9 in donkeys
after the primary inoculation. Viral RNA was detected consistently up
to day 47 in some animals and intermittently thereafter. There was no
evidence of a second viraemia in any of the animals after challenge.
The detection of specific antibodies, against AHSV 4 NS3 protein, in a
ll animals confirmed that both donkeys and mules were infected and tha
t the virus had replicated.