Presence and survival of African swine fever virus in leeches

•ASFV can spread in the environment and infect pigs via water and food, mostly through ingestion and occasionally through skin contact.•ASFV is able to survive in several environments, notably in water, food and soil.•The aim was to study the ability of leeches to persistently harbor ASFV.•Also leeches excrete the virus, we observed the features of this excretion, as well as the persistence of indefectibility of the excreted viruses. This research is focused on the study of African swine fever virus (ASFV) survival in the leech Hirudo medicinalis. To detect the infection route of the virus in leeches, two introduction methods were used: blood-feeding from infected swine hosts and exposure to ASFV-contaminated water (leeches cultivated with ASFV). This study found that the survival of ASFV in leeches was much longer than that in leech-free medium. The persistent presence of the virus in leeches and leech excretion was detected in both groups. The virus excreted from both groups of leeches in the terminal stages of the experiment was able to induce productive infection in porcine alveolar macrophages. In an attempt to understand ASFV, transmission to pigs was conducted through the ingestion of leech-cultivated water and leeches that had fed on ASFV-infected animals or that were cultivated environmentally with the virus. The ingestion of some samples at 60–80 days after cultivation demonstrated successful ASFV transmission via per os infection. In conclusion, leeches can serve as a possible reservoirs for ASFV in the absence of its main hosts – pigs and some ticks of the genus Ornithodoros.