Fig 1.
Experimental outline of experiments using viremic pigs to attempt soft tick infection depicting subsequent tests for ASFV transmission to pigs.
Viremia was produced by inoculating naïve pigs intramuscularly with ASFV. Infection of three Ornithodoros soft tick species was attempted by allowing the ticks to blood feed on the viremic pigs. Two to eight months after feeding on viremic pigs, additional experiments were conducted to test the ability of these ticks to transmit different ASFV strains while acquiring a blood meal on naïve pigs. OmG: O. moubata-Georgia2007/1, OmL: O. moubata-Liv13/33, OeG: O. erraticus-Georgia2007/1, OeO: O. erraticus-OurT88/1, OvZ: O. verrucosus-Ukr12/Zapo.
Table 1.
Soft ticks fed on viremic pigs in two trials to attempt infection with four ASFV strains.
Counts of engorged ticks for each Ornithodoros species tested are shown next to the number of pigs in brackets that were infected with the respective ASFV strain per trial.
Fig 2.
Detection of ASFV VP72 gene in soft ticks by real time PCR.
ASFV infection was tested in soft ticks for the following viral strain associations: O. moubata-Liv13/33 (OmL), O. moubata-Georgia2007/1 (OmG), O. erraticus-OurT88/1 (OeO), O. erraticus-Georgia2007/1 (OeG) and O. verrucosus-Urk12/Zapo (OvZ). Ct = Cycle Threshold.
Table 2.
ASFV transmission by O. moubata ticks.
Experiments involved ticks previously exposed to ASFV strains OmL, OmG, and the descendants of OmL ticks. F = female, M = male, N = nymph, OmL = O. moubata-Liv13/33, OmG = O. moubata-Georgia2007/1.
Table 3.
Lack of ASFV transmission by O. erraticus and O. verrucosus ticks.
Experiments involved ticks previously exposed to ASFV strains. F = female, M = male, N = Nymph, OeO = O. erraticus-OurT88/1, OeG = O. erraticus-Georgia2007/1, OvZ = O. verrucosus-Zapo.
Table 4.
Clinical outcome in pigs inoculated with homogenate supernatant of O. erraticus and O. verrucosus previously exposed to selected ASFV strains.
Experiments involved ticks previously exposed to ASFV strains. OeO = O. erraticus-OurT88/1, OeG = O. erraticus-Georgia2007/1, OvZ = O. verrucosus-Zapo.
Table 5.
Failure of ASFV transmission after repeated blood feeding by O. erraticus and O. moubata ticks previously exposed to selected ASFV strains.
Proportions of soft ticks fed and their life stage and sex per experiment are shown. F = Female, M = male, N = Nymph. OeG = O. erraticus-Georgia2007/1, OmG = O. moubata-Georgia2007/1.