Prevalence and risk factors associated with Sarcocystis neurona infections in opossums (Didelphis virginiana) from central California

Daniel Rejmanek, Elizabeth Vanwormer, Melissa A. Miller, Jonna A.K. Mazet, Amy E. Nichelason, Ann C. Melli, Andrea E. Packham, David A. Jessup, Patricia A. Conrad

Research output: Contribution to journalArticlepeer-review

26 Scopus citations


Sarcocystis neurona, a protozoal parasite shed by opossums (Didelphis virginiana), has been shown to cause significant morbidity and mortality in horses, sea otters, and other marine mammals. Over the course of 3 years (fall 2005-summer 2008), opossums from central California were tested for infection with S. neurona. Of 288 opossums sampled, 17 (5.9%) were infected with S. neurona based on the molecular characterization of sporocysts from intestinal scrapings or feces. Risk factors evaluated for association with S. neurona infection in opossums included: age, sex, location, season, presence of pouch young in females, concomitant infection, and sampling method (live-trapped or traffic-killed). Multivariate logistic regression analysis identified that opossums in the Central Valley were 9 times more likely to be infected than those near the coast (p = 0.009). Similarly, opossum infection was 5 times more likely to be detected during the reproductive season (March-July; p = 0.013). This first investigation of S. neurona infection prevalence and associated risk factors in opossums in the western United States can be used to develop management strategies aimed at reducing the incidence of S. neurona infections in susceptible hosts, including horses and threatened California sea otters (Enhydra lutris neries).

Original languageEnglish (US)
Pages (from-to)8-14
Number of pages7
JournalVeterinary Parasitology
Issue number1-2
StatePublished - Dec 3 2009
Externally publishedYes


  • California
  • Didelphis virginiana
  • Opossum
  • Prevalence
  • Risk factors
  • Sarcocystis neurona
  • Sporocysts

ASJC Scopus subject areas

  • Parasitology
  • General Veterinary


Dive into the research topics of 'Prevalence and risk factors associated with Sarcocystis neurona infections in opossums (Didelphis virginiana) from central California'. Together they form a unique fingerprint.

Cite this