Needle-free intradermal injection prevents ASF transmission – Abstracts
Shared needles are a potential iatrogenic and hematogenous non-live vector of African swine fever virus (ASV) on farms.
Methods: To assess possible transmission, 60 4-week-old pigs from an ASF-free farm were randomly assigned to two groups upon arrival. The 1st group consisted of infected pigs, which were randomly distributed into 4 groups. The remaining pigs (group 2) were divided into 8 groups and served as sentinels. Pigs in group 1 were infected oronasally with African swine fever virus at high (108 copies/ml), moderate (106 copies/ml) or low (101 copies/ml) titers, except for a subgroup that remained unexposed (1). negative control). At 7 days post-challenge (peak viremia), vaccine adjuvant was administered intradermally and intramuscularly to four groups of infected pigs using a needle-free device and conventional needles, respectively. The same volume of adjuvant was then administered to Group 2 (n = 48) using the same needle or needleless device. All pigs were screened daily for clinical disease and analyzed for ASFV DNA using quantitative PCR.
Results: All pigs in group 1 developed viremia (except control group pigs). ASFV viremia was detected in all sentinel groups that received intramuscular injection. The rate of intramuscular transmission through common needles was positively correlated with the titer of virus in the circulation of infected individuals. Sentinels exposed to intramuscular needles from high-titer infected individuals experienced more severe and acute clinical disease than those exposed to low-titer infected individuals. In control groups administered intradermally, no viremia or clinical signs were observed.
Conclusion: This study confirmed hematogenous transmission of African swine fever virus among pigs through needle sharing.
Salman M, Lin H, Sunthisukwattana R, et al. Intradermal needleless injections prevent transmission of African swine fever, whereas intramuscular needle injections do not. Scientific reports. 2023; 13:4600. https://doi.org/10.1038/s41598-023-31199-2