Abstract
African swine fever virus (ASFV), a highly contagious and lethal virus affecting domestic and wild pigs, has raised global concerns due to its continued spread across Europe and Asia. While traditional transmission pathways involve suids and soft ticks, this study investigates the potential role of freshwater gastropods as environmental reservoirs capable of sustaining ASFV. We analysed ASFV survival in ten gastropod species after long-term co-incubation with the virus. Viral transcriptional activity, particularly of the late gene B646L and members of the multigene family MGF505, was evaluated in snail faeces up to nine weeks post-infection. Results revealed that several gastropods, including Melanoides tuberculata, Tarebia granifera, Physa fontinalis, and Pomacea bridgesii, support long-term persistence of ASFV, accompanied by increased MGF505 gene expression. Notably, the simultaneous activation of MGF5052R and MGF50511R significantly correlated with higher B646L expression and extended viral survival, suggesting a functional role in ASFV maintenance. Conversely, antiviral (AV) activity assays showed that some gastropod faeces reduced replication of the unrelated Influenza virus, hinting at induced host defences. A negative correlation was observed between AV activity and the expression of MGF505 2R/11R, implying that ASFV may suppress antiviral responses to facilitate persistence. These findings suggest that certain gastropods may serve as overlooked environmental hosts, contributing to ASFV epidemiology via long term viral shedding. Further research is needed to clarify the mechanisms underlying ASFV-host interactions and to assess the ecological and epidemiological implications of gastropods in ASFV transmission cycles.