The evolutionary pattern of FPLV in cats differs from that of CPV in dogs. Since FPLV is in evolutionary stasis in cats, FPLV mainly evolves with random genetic drift . In contrast, CPV appears to evolve in dogs under certain positive selection on the VP2 protein , which may be because of its short history in dogs. How CPVs are evolving in cats remains relatively obscure. Since CPV-2a and 2b are likely to act as newly emerging parasites in cats, some cat-specific positive selection(s), such as relative in vivo fitness and immune surveillance, could operate as a driving force of CPV evolution. The emergence of CPV-2c in leopard cats is a good example of the evolution of CPV in new hosts. Similarly, since specific antibodies against CPV have been detected in a wide range of wild animals, such as large felids, wildcats, civets, otters, and even bears, such interspecies transmissions probably result in accelerated emergence of other new antigenic types of CPVs because of the new host-specific positive selection.
Elucidating how feline parvoviruses are evolving and how newly emerging variants behave may help to prevent a possible outbreak of the new variant. Assuming that a new virulent CPV variant emerges in cats in the future, what can we expect? Fortunately, the newly emerging variant will not likely cause rapid outbreaks in cats or dogs, since FPLV and CPV-2a/2b have been actively circulating in carnivore populations. Commercially available FPLV or CPV-2-based vaccines might also protect animals from the new virus infection. However, if the new virus gains wider host ranges, deadly outbreaks could be observed, as when CPV-2 emerged in dogs. In any case, recent isolates need to be investigated to anticipate and assess the risk caused by newly emerging viruses.
We thank C. R. Parrish for providing monoclonal antibodies (MAbs) A3B10, B6D5, B2G11, B4E1, A4E3, C1D1, and B4A2; and M. Horiuchi for providing MAb P2-215. We thank Blair L. Strang for extensive comments and suggestions for improving the manuscript.Reprint Address
Address for correspondence: Yasuhiro Ikeda, Department of Immunology and Molecular Paathology, Windeyer Institute of Medical Sciences, University College London, 46 Cleveland Street, London W1T 4JF, UK; fax: 0207-679-9357; e-mail: firstname.lastname@example.org
Emerging Infectious Diseases. 2002;8(4) © 2002 Centers for Disease Control and Prevention (CDC)
Cite this: Feline Host Range of Canine parvovirus: Recent Emergence of New Antigenic Types in Cats - Medscape - Apr 01, 2002.