A consortium of researchers from Australia and the US (Roediger et al. Cell 2018) recently published the discovery of a novel mouse parvovirus which causes significant clinical illness in immunocompromised mice. This highly infectious virus, called mouse kidney parvovirus (MKPV), causes inclusion body nephropathy (a type of kidney disease) and eventually renal failure in immunodeficient mice. In affected mice, kidneys display anatomical and functional abnormalities including tubular degeneration, necrosis and fibrosis as well as elevated serum creatinine and blood urea nitrogen. Affected mice may also lose weight and become anemic¹. MKPV is reported to be widely distributed in North American and Australian laboratory animal facilities (status of other locations is unknown at this time), with IDEXX reporting prevalence of over 15%². The virus is transmitted via fecal-oral or urinary-oral routes. Immunocompetent mice may be infected with MKPV, but show minimal clinical illness, with some animals displaying moderate nephropathy. Affected nude mice (which lack T cells) are reported to show mild nephropathy. In more severely immunodeficient mice such as Rag1 knockouts, scids or NSG mice, MKPV causes more significant nephropathy and may cause death. Affected animals may experience kidney dysfunction for 4-5 months prior to death¹.

Taconic has screened all commercial mouse production locations for the presence of this agent and is pleased to announce that all Taconic commercial mouse colonies and contract mouse breeding barriers are negative for MKPV. Taconic attributes this result to the strength of its biosecurity program, which includes practices and procedures designed to prevent entry or spread of viral contaminants.

Taconic routinely evaluates its health testing program and updates it based on scientific findings and customer concern. Because this agent has significant clinical impact in immunodeficient mice and may cause mild nephropathy even in immunocompetent mice, Taconic has added MKPV to the exclusion list for all Taconic health standards. Regular testing will commence starting in July 2019, and MKPV test results will appear on health reports as of June 4, 2019. It is anticipated that Taconic's strict bioexclusion practices will continue to prevent entry of this agent.