title: Specific-pathogen-free status is associated with lower infant mortality rate in rhesus macaque (Macaca mulatta) colonies at the California National Primate Research Center.
abstract: BACKGROUND
  Specific-pathogen-free (SPF) rhesus macaques, Macaca mulatta, are a valuable resource in biomedical research, and demographic analysis plays a significant role in colony management.
  
  
  METHODS
  Data collection included SPF levels, gender, birth year, season of birth, birth location, rearing condition, maternal pregnancy history, and maternal age. Infant mortality in SPF rhesus macaques was compared with that in non-SPF rhesus macaques at the California National Primate Research Center over a six-year period, using Cox proportional regression analysis.
  
  
  RESULTS
  In infants born to multiparous dams, the SPF infants had a significantly lower rate of mortality than non-SPF infants. There was no statistically significant difference in infant mortality between different SPF levels.
  
  
  CONCLUSIONS
  Elimination of selected endemic viruses from breeding populations of rhesus macaques for the purpose of SPF colony development is associated with a significant reduction in the infant mortality rate.
authors.affiliation: New England Primate Research Center, Harvard Medical School, Southborough, MA, USA. takayuki_tanaka@hms.harvard.edu
authors.forename: Takayuki
authors.initials: T
authors.lastname: Tanaka
authors.forename: Nicholas W
authors.initials: NW
authors.lastname: Lerche
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Farver
authors.forename: Amir
authors.initials: A
authors.lastname: Ardeshir
authors.forename: Philip H
authors.initials: PH
authors.lastname: Kass
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000502:physiology* / Q000821:virology; D001947:Breeding; D005260:Female; D008253:Macaca mulatta / Q000502:physiology* / Q000821:virology; D008297:Male; D008992:Monkey Diseases / Q000401:mortality / Q000821:virology; D009026:Mortality; D011247:Pregnancy; D012189:Retrospective Studies; D013047:Specific Pathogen-Free Organisms / Q000502:physiology*; D014777:Virus Diseases / Q000401:mortality / Q000662:veterinary
keywords: Cox proportional regression; epidemiology; hazard ratio; nonhuman primate; rhesus monkey; survival analysis