Transmission of the caprine arthritis-encephalitis virus through artificial insemination

The objective of present study was to evaluate the transmissibility of the caprine arthritis-encephalitis virus (CAEV) through artificial insemination (AI), and to assess the influence of viral load on this probable transmission. It also aims to verify whether the inflammatory process caused by the use of intravaginal sponges would facilitate virus entry in the female reproductive tract. For this purpose, 30 undefined breed goats were used, all serologically negative for CAEV. One Anglo-Nubian buck, also seronegative, was used to artificially inseminate females in this study. His semen was contaminated with the standard CAEV-Cork virus strain, with two distinct infective titres, one 106 TCID50/mL, for high viral load (HVL), and another of 102 TCID50/mL, for low viral load (LVL). Females had estrus synchronised by using two protocols, intravaginal sponges in Group 1 (G1, N = 15) and auricular subcutaneous implants in Group 2 (G2, N = 15). For inseminations, the goats were divided into three groups of 10 animals each. One group was inseminated with HVL, another with LVL and the third with semen from the same virus-free buck, as a negative control. The experiment was conducted in accordance to the ethical principles for animal experimentation. Statistical analyses were performed by the chi-square test (P < 0.05). Thirty days after insemination, the experimental infection was confirmed, when 12 out of the 20 (60%) inseminated goats had seroconverted. Sixty days after insemination, all females from the HVL and LVL groups presented anti-CAEV antibodies. There was no statistical difference (P > 0.05) among groups regarding viral loads nor between the two estrus synchronisation protocols. Goats from the control group remained seronegative throughout the experiment (12 months). Concerning reproductive parameters, no difference was found between the control group and the infected groups. Based on these results, it is possible to conclude that the virus can be transmitted through artificial insemination with infected semen. Therefore, the venereal route is a potential route of infection.