Growth of the equine infectious anemia virus in a continuous-passage horse leukocyte culture.

The research article describes the successful growth of the equine infectious anemia virus in a continuously-passaged horse leukocyte culture, with the virus’s size being confirmed through ultrafiltration studies. The subsequent infection of horses with both filtered and unfiltered culture viruses resulted in observable disease signs and lesions.

Growth of the Virus in Leukocyte Culture

• The researchers utilized a continuous-passage horse leukocyte culture (previously mentioned as V.B. 40) to encourage the growth of the equine infectious anemia virus.
• Subsequent observations of the culture indicated susceptibility, as the virus took hold, multiplied, and demonstrated noticeable changes (cyto-pathic effect) in the infected cells. They also calculated the viral titre—a concentration measurement of the virus.

Size of the Virus

• Following the confirmation of successful virus growth, the researchers conducted ultrafiltration studies to estimate the size of the virus.
• The ultrafiltration process showed that the virus was smaller than 32 mμ (millimicrons) in diameter, falling in line with previous similar research findings.

Infection of Horses

• The next step of the study involved inoculating susceptible horses with the culture-grown viruses. The aim was to observe if the cultured virus could induce the disease in the animals, hence confirming its infectious capability.
• The horses were inoculated with viruses in two different forms – unfiltered and ultrafiltered. Both types successfully induced clinical signs and lesions related to equine infectious anemia in the horses. This proved that the virus grown in the leukocyte culture was indeed infectious and capable of causing disease in horses.