Introduction of a Divergent Canine Parvovirus Type 2b Strain with a Dog in Sicily, Southern Italy, Through the Mediterranean Sea Route to Europe

Abstract

Despite over four decades since its emergence, canine parvovirus type 2 (CPV-2) remains a relevant disease for dogs. Few studies, primarily only recent ones based on phylodynamic and phylogeography approaches, have highlighted the impact of rapid and long-distance transport of dogs on the CPV-2 spreading dynamics. The present study reports the genomic characterization of a CPV-2 strain detected in a dog introduced into Italy from the coasts of North Africa through the Mediterranean Sea route to Europe. The nearly complete CPV-2 sequence was obtained and analyzed. The viral isolate was characterized as a CPV-2b variant, showing genetic signatures distinct from those of CPV-2 strains detected to date in Europe. Phylodynamic and phylogeographic approaches revealed a close correlation with CPV-2 strains recently reported in the Middle East (Turkey and Egypt), which likely originated or co-evolved from Asian ones. It is at least suggestive that the inferred spreading pattern overlaps with the routes often followed by migrants travelling from Asia and Middle East to Europe, passing through Africa. This evidence for the introduction of CPV-2 via the Mediterranean Sea route to Europe highlights the relevant role of the dog movements in the global spread of emerging or re-emerging viral pathogens.

Keywords: Europe; Turkey; canine parvovirus type 2; dogs; genomics; mediterranean sea; northern Africa; phylogeography; transients and migrants.

Figure 1

A schematic representation of the CPV-2 genome: the upper lines (A) represent the complete encoding nucleotide length (4269 nucleotides) of the genome, excluding the 5′ to the 3′ UTRs, and the relative positions of the NS1 and VP2 genes; the middle ((B), in blue) and lower ((C), in red) lines represent the relative positions of the described amino-acid changes in the NS1 and VP2 gene sequences, respectively.

Figure 2

Maximum clade credibility tree of CPV2 strains based on VP2 sequence. Countries where the virus ancestors were estimated to circulate are color-coded. The branch length is scaled in time (years). The clade including the sequence obtained in the present study (highlighted in yellow) is reported in the right insert. Tree nodes are annotated with the estimated year.

Figure 3

Geographical map of the Mediterranean basin, including year and country of detection of the most related CPV-2b strain to the one described in this study (strain IZSSI_2024PA10625), spreading from Africa to Italy. For each strain, the strain name and the accession number were provided. Each strain refers to the following references: (from Egypt) strain EGY/2019/39-517 [43], EGY-FVMVL-18/2019 [44]; (from Turkey) CPV-2b-O1-TR [45], Turkey_Izmir_2, and Turkey_Ankara_2 [46]. The main image was obtained from Google Earth (Google Landsat / Copernicus Data SIO, NOAA, U.S. Navy, NGA, GEBCOInst. Geogr. NacionalGeoBasis-DE/BKG (©2009) Mapa GISrael).