The rapid spread of the virus over the African pig (ASFVfor its acronym in English), which causes severe disease with often high mortality rates in Eurasian Suids, is prevalent as a threat to pig populations and dependent industries worldwide.
Although advancing scientific progress continually improves the understanding of the pathogenesis of African swine fever virus, alternative transmission routes have not yet been evaluated for African swine fever virus.
This is why a group of researchers from the Instituto Friedrich Loeffler (FLI) of Germany, and the US state universities of Iowa and South Dakota have studied one of these alternative routes, specifically through the process of artificial insemination.
“In modern pig production, semen from a single animal is used to inseminate many herds of sows. Therefore, infection of a stallion presents the risk of rapid and wide distribution of the African swine fever virus within the same country or among several countries”, the researchers note.
To perform the study Intramuscular inoculation with the ASFV ‘Estonia 2014’ strain was carried out in four stallions. Following this, the authors detected infectious virions in semen samples from the second day after inoculation, and the semen samples remained positive by both qPCR and hemadsorption testing for at least 20 days.
Finally, they used these samples to inseminate a group of 14 sows. Some tested positive 7 days after insemination, but they all ended up testing positive within 35 days.
As the pregnancy developed, the most of the sows aborted or reabsorbed the embryos with the onset of fever. Of course, some of the fetuses that did develop showed abnormalities and replication of the African swine fever virus in their tissues.
“We present evidence from efficient transmission of ASFV to gilts through artificial insemination and also to implanted embryos. These results underscore the fundamental role that semen could play boar in the transmission of the African swine fever virus”, they conclude.
For all these reasons, they consider that “these findings, together with the insemination procedures used in the modern swine industry, indicate that the venereal transmission of the African swine fever virus should be considered in future risk assessment strategies”.