“…In Europe, only cowpox virus is known to circulate in the nature and to cause human infections. However, laboratory and vaccine use of vaccinia virus [Lewis et al, 2006] including recombinant vaccine viruses used, for example, for wildlife rabies vaccination [Rupprecht et al, 2001] has also caused human infections and/or complications and vaccinia virus has escaped to natural reservoirs on several occasions [Dumbell and Richardson, 1993;Damaso et al, 2000;de Souza Trindade et al, 2003]. Moreover, imported OPVs are always a possibility as seen during the emergence of monkeypox virus in the USA in 2003 [Anonymous, 2003;Reed et al, 2004].…”