Artificial insemination may be an alternative route of transmission of the ASF virus

A recent study showed that the virus can be efficiently transmitted from infected wild boars to uninfected female recipients by this route.

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The rapid spread of African swine fever (ASF) virus, which causes severe disease with often high mortality rates, remains a threat to pig populations and related industries worldwide. Although ongoing scientific progress continually improves understanding of ASFV pathogenesis, alternative modes of transmission have not yet been explored.

A recent study showed that ASFV can be efficiently transmitted from infected wild boars to uninfected female recipients through artificial insemination (AI). In modern pig farming, semen from pig farms is often supplied to many herds of sows. Thus, contamination of a wild boar farm poses a risk of rapid and widespread spread of ASF virus within or between countries.

Daily collection of blood and semen from four wild boars after intramuscular inoculation with the Estonia 2014 strain of ASF virus led to the detection of virus genomes in semen already 2 days after vaccination, in blood – 1 day after vaccination, in blood – 1 day after vaccination . while sperm quality was virtually unaffected. Finally, after insemination with extended semen, 7 of 14 females tested positive for ASF virus 7 days after insemination, and all females tested positive 35 days after insemination.

Twelve of 13 pregnant women aborted or underwent reabsorption at the onset of fever. In some fetuses derived from remaining sows, both abnormalities and replication of the ASF virus in fetal tissues were observed. In summary, the study provides evidence for efficient transmission of ASFV to females via AI as well as to implanted embryos. These results highlight the critical role that wild boar semen may play in ASF virus transmission.

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Friedrichs W., Reiks D., Hasenfuss T., Gerstenkorn E., Zimmerman J. J., Nelson E. A., Carrau T., Deutschmann P., Sehl-Ewert J., Roschick H., Beer M., Christopher-Hennings J, Blom S. Artificial insemination as an alternative route of transmission for African swine fever virus. Pathogens. 2022, December 14; 11 (12): 1539. doi: 10.3390/pathogens11121539. PMID: 36558873; PMCID: PMC9785317.