Prevalence and risk factors associated with Sarcocystis neurona infections in opossums (Didelphis virginiana) from central California.
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).
Rejmanek
Daniel
D
Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA. drejmanek@ucdavis.edu
Vanwormer
Elizabeth
E
Miller
Melissa A
MA
Mazet
Jonna A K
JA
Nichelason
Amy E
AE
Melli
Ann C
AC
Packham
Andrea E
AE
Jessup
David A
DA
Conrad
Patricia A
PA
D000367:Age Factors; D000818:Animals; D002140:California / Q000453:epidemiology; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D048293:Didelphis / Q000469:parasitology*; D005260:Female; D008297:Male; D015999:Multivariate Analysis; D015995:Prevalence; D012307:Risk Factors; D012522:Sarcocystis / Q000235:genetics / Q000502:physiology*; D012523:Sarcocystosis / Q000453:epidemiology / Q000662:veterinary*; D012621:Seasons; D012737:Sex Factors
D021903:DNA, Ribosomal Spacer