title: Unsterilized feed as the apparent cause of a mouse parvovirus outbreak.
abstract: In early 2009, we experienced a widespread outbreak of mouse parvoviruses 1 and 2 (MPV) at our institution, which encompasses approximately 50,000 cages located in 7 campus vivaria. MPV had not been detected for several years; however, during a single 4-mo sentinel-testing rotation comprising all racks at the institution, 72 of 927 rack sentinels tested serologically positive for MPV1, MPV2, or both. PCR of fecal samples from several index cases confirmed MPV. Each sentinel-positive rack contained between 0 and 10 infected colony cages. Positive racks appeared to be randomly distributed, although several small facilities escaped infection. We investigated how this infection may have entered the facilities, in which mice were maintained in barrier caging with sterilized feed, bedding, and equipment, and procedures were in place to prevent incoming infection and cross-contamination. The only widespread change that occurred during the 3 mo preceding the first positive test was that every cage had been treated for 12 wk with an unsterilized fenbendazole-medicated diet. At the completion of fenbendazole treatment, sterilized feed was reinstituted. Evidence of MPV infection was eliminated within 7 mo via an intensive test-and-remove policy in combination with movement controls, and we have had no further positive tests in the 3.5 y since the outbreak. Although the possibility remains that MPV infection resulted from fomites or undetected infections in incoming mice, the timing and extent of this outbreak together with the complete absence of new cases after sterilized feed was reinstituted strongly implicate unsterilized feed as the source of this MPV outbreak.
authors.affiliation: Department of Molecular and Comparative Pathobiology Johns Hopkins University School of Medicine, Baltimore, Maryland, USA. Julie.watson@jhu.edu
authors.forename: Julie
authors.initials: J
authors.lastname: Watson
mesh_terms: D000821:Animal Feed / Q000821:virology*; D000818:Animals; D004196:Disease Outbreaks; D005243:Feces / Q000821:virology; D005516:Food Microbiology; D006799:Housing, Animal / Q000592:standards; D008297:Male; D051379:Mice; D010322:Parvoviridae Infections / Q000453:epidemiology / Q000662:veterinary* / Q000821:virology; D017992:Parvovirus / Q000235:genetics / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction / Q000662:veterinary; D012376:Rodent Diseases / Q000453:epidemiology* / Q000821:virology*
references.citation: J Hosp Infect. 2009 Sep;73(1):64-70
references.pmid: 19646784
references.citation: J Am Assoc Lab Anim Sci. 2008 Nov;47(6):37-40
references.pmid: 19049251
references.citation: Comp Med. 2000 Oct;50(5):498-502
references.pmid: 11099132
references.citation: Lab Anim (NY). 2009 May;38(5):161-5
references.pmid: 19384313
references.citation: J Am Assoc Lab Anim Sci. 2010 Jan;49(1):11-21
references.pmid: 20122310
references.citation: Lab Anim. 2009 Apr;43(2):165-73
references.pmid: 19015179
references.citation: J Am Assoc Lab Anim Sci. 2011 Jul;50(4):516-22
references.pmid: 21838982
references.citation: Lab Anim. 2006 Apr;40(2):137-43
references.pmid: 16600073
references.citation: J Am Assoc Lab Anim Sci. 2009 May;48(3):263-7
references.pmid: 19476714
references.citation: Transplantation. 1998 Jun 15;65(11):1436-46
references.pmid: 9645799
references.citation: Lab Anim (NY). 2011 May;40(5):145-52
references.pmid: 21508953
references.citation: Lab Anim. 2011 Oct;45(4):271-5
references.pmid: 21508117
references.citation: Comp Med. 2007 Feb;57(1):90-6
references.pmid: 17348296
references.citation: J Am Assoc Lab Anim Sci. 2009 Jul;48(4):381-6
references.pmid: 19653946
references.citation: J Am Assoc Lab Anim Sci. 2010 Jul;49(4):437-42
references.pmid: 20819389
references.citation: Transplantation. 1996 Jan 27;61(2):292-9
references.pmid: 8600639
references.citation: Lab Anim. 2007 Apr;41(2):229-38
references.pmid: 17430622