Abstract
Emerging Viral Pathogens
An ongoing concern in veterinary and public health is the rapidity with which genetic reassortment may generate novel pathogenic viruses with zoonotic potential. This is best illustrated by influenza viruses. Recent controversial research designed to understand influenza viral pathogenicity in mammalian hosts has fueled international discussion. Similarly provocative is the Schmallenberg virus, a new bunyavirus infecting ruminants in a growing swath of Europe, whose transmission may primarily rely on a previously geographically, restricted arthropod vector.
Schmallenberg Virus: A Short-Lived Plague?
Featured in this issue is a report describing the macroscopic and histologic changes associated with natural Schmallenberg viral infection of ruminant neonates (Herder et al, “Dominating Morphological Findings in Domestic Ruminants Caused by the Emerging So-Called Schmallenberg Virus in Germany”). The spread of Culicoides-borne disease into northern Europe, enabling bunyavirus exposure to potentially new vectors, hosts, and environments, is a focus of scientific and economic concern. Bluetongue and now Schmallenberg virus have appeared de novo in a very similar geographical range, enabling old and new viruses to spread into new territories. What will be the outcome of this new viral epidemic? Previous exposure results in immunity, so the likely evolution would be toward a disease affecting only young, naive animals. Diagnostic laboratory surveillance across Europe is critical for documenting the viral evolution and disease trends.
Europe is bracing for the anticipated wave of congenital deformities and stillbirths caused by the newly described Schmallenberg virus (Science, 2012;
The Deadly Pandemic That Never Comes: H5N1
What are the implications of determining factors that permit efficient transmission of the highly pathogenic H5N1 influenza virus between mammals? A global debate regarding whether full publication of “the two most famous scientific papers that have never been published” should be permitted seems to be concluding with a cautious “yes.” While the information may well perk the interest of malcontents, mutations identified in the studies could aid H5N1 surveillance (Science, 2012;
Laboratory Animals: Using Different Rat and Mouse Strains? It’s Complicated!
The unexpected can be expected, or at least anticipated, when working with new genetic strains, (LaPerle et al, “A Prostate Fibromyxoid Sarcoma With Smooth Muscle Differentiation in a F344xBNF1 Rat”). In this issue of Veterinary Pathology, the authors describe an unusual case of a sarcoma in the prostate of a F44xBNF1 rat with smooth muscle differentiation confirmed by demonstration of smooth muscle actin. The mass stained strongly with Masson’s trichrome and vimentin throughout, and approximately 5% of the neoplastic cells were positive for smooth muscle actin. In some strains of rat, such as intact male ACI/Seg rats, 70% over the age of 20 months will develop carcinomas of the ventral prostate (Shirai et al, Mutant Res, 2000;