Skip to main content
NCBI home page
Applied and Environmental Microbiology logoLink to Applied and Environmental Microbiology
. 1997 Oct;63(10):3946–3949. doi: 10.1128/aem.63.10.3946-3949.1997

Prevalence of and associated risk factors for shedding Cryptosporidium parvum oocysts and Giardia cysts within feral pig populations in California.

E R Atwill 1, R A Sweitzer 1, M G Pereira 1, I A Gardner 1, D Van Vuren 1, W M Boyce 1
PMCID: PMC168707  PMID: 9327560

Abstract

Populations of feral pigs (Sus scrofa) may serve as an environmental reservoir of Cryptosporidium parvum oocysts and Giardia sp. cysts for source water. We conducted a cross-sectional study to determine the prevalence of and associated demographic and environmental risk factors for the shedding of C. parvum oocysts and Giardia sp. cysts. Feral pigs were either live-trapped or dispatched from 10 populations located along the coastal mountains of western California, and fecal samples were obtained for immunofluorescence detection of C. parvum oocysts and Giardia sp. cysts. We found that 12 (5.4%) and 17 (7.6%) of 221 feral pigs were shedding C. parvum oocysts and Giardia sp. cysts, respectively. The pig's sex and body condition and the presence of cattle were not associated with the probability of the shedding of C. parvum oocysts. However, younger pigs (< or = 8 months) and pigs from high-density populations (> 2.0 feral pigs/km2) were significantly more likely to shed oocysts compared to older pigs (> 8 months) and pigs from low-density populations (< or = 1.9 feral pigs/km2). In contrast, none of these demographic and environmental variables were associated with the probability of the shedding of Giardia sp. cysts among feral pigs. These results suggest that given the propensity for feral pigs to focus their activity in riparian areas, feral pigs may serve as a source of protozoal contamination for surface water.

Full Text

The Full Text of this article is available as a PDF (163.0 KB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Atherton F., Newman C. P., Casemore D. P. An outbreak of waterborne cryptosporidiosis associated with a public water supply in the UK. Epidemiol Infect. 1995 Aug;115(1):123–131. doi: 10.1017/s0950268800058180. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Balatbat A. B., Jordan G. W., Tang Y. J., Silva J., Jr Detection of Cryptosporidium parvum DNA in human feces by nested PCR. J Clin Microbiol. 1996 Jul;34(7):1769–1772. doi: 10.1128/jcm.34.7.1769-1772.1996. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Bridgman S. A., Robertson R. M., Syed Q., Speed N., Andrews N., Hunter P. R. Outbreak of cryptosporidiosis associated with a disinfected groundwater supply. Epidemiol Infect. 1995 Dec;115(3):555–566. doi: 10.1017/s0950268800058726. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. DuPont H. L., Chappell C. L., Sterling C. R., Okhuysen P. C., Rose J. B., Jakubowski W. The infectivity of Cryptosporidium parvum in healthy volunteers. N Engl J Med. 1995 Mar 30;332(13):855–859. doi: 10.1056/NEJM199503303321304. [DOI] [PubMed] [Google Scholar]
  5. Garber L. P., Salman M. D., Hurd H. S., Keefe T., Schlater J. L. Potential risk factors for Cryptosporidium infection in dairy calves. J Am Vet Med Assoc. 1994 Jul 1;205(1):86–91. [PubMed] [Google Scholar]
  6. Goldstein S. T., Juranek D. D., Ravenholt O., Hightower A. W., Martin D. G., Mesnik J. L., Griffiths S. D., Bryant A. J., Reich R. R., Herwaldt B. L. Cryptosporidiosis: an outbreak associated with drinking water despite state-of-the-art water treatment. Ann Intern Med. 1996 Mar 1;124(5):459–468. doi: 10.7326/0003-4819-124-5-199603010-00001. [DOI] [PubMed] [Google Scholar]
  7. Graczyk T. K., Cranfield M. R., Fayer R. Evaluation of commercial enzyme immunoassay (EIA) and immunofluorescent antibody (FA) test kits for detection of Cryptosporidium oocysts of species other than Cryptosporidium parvum. Am J Trop Med Hyg. 1996 Mar;54(3):274–279. doi: 10.4269/ajtmh.1996.54.274. [DOI] [PubMed] [Google Scholar]
  8. Hayes E. B., Matte T. D., O'Brien T. R., McKinley T. W., Logsdon G. S., Rose J. B., Ungar B. L., Word D. M., Pinsky P. F., Cummings M. L. Large community outbreak of cryptosporidiosis due to contamination of a filtered public water supply. N Engl J Med. 1989 May 25;320(21):1372–1376. doi: 10.1056/NEJM198905253202103. [DOI] [PubMed] [Google Scholar]
  9. Johnson E., Atwill E. R., Filkins M. E., Kalush J. The prevalence of shedding of Cryptosporidium and Giardia spp. based on a single fecal sample collection from each of 91 horses used for backcountry recreation. J Vet Diagn Invest. 1997 Jan;9(1):56–60. doi: 10.1177/104063879700900110. [DOI] [PubMed] [Google Scholar]
  10. Laxer M. A., Timblin B. K., Patel R. J. DNA sequences for the specific detection of Cryptosporidium parvum by the polymerase chain reaction. Am J Trop Med Hyg. 1991 Dec;45(6):688–694. doi: 10.4269/ajtmh.1991.45.688. [DOI] [PubMed] [Google Scholar]
  11. LeChevallier M. W., Norton W. D., Lee R. G. Occurrence of Giardia and Cryptosporidium spp. in surface water supplies. Appl Environ Microbiol. 1991 Sep;57(9):2610–2616. doi: 10.1128/aem.57.9.2610-2616.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Levine J. F., Levy M. G., Walker R. L., Crittenden S. Cryptosporidiosis in veterinary students. J Am Vet Med Assoc. 1988 Dec 1;193(11):1413–1414. [PubMed] [Google Scholar]
  13. Mac Kenzie W. R., Hoxie N. J., Proctor M. E., Gradus M. S., Blair K. A., Peterson D. E., Kazmierczak J. J., Addiss D. G., Fox K. R., Rose J. B. A massive outbreak in Milwaukee of cryptosporidium infection transmitted through the public water supply. N Engl J Med. 1994 Jul 21;331(3):161–167. doi: 10.1056/NEJM199407213310304. [DOI] [PubMed] [Google Scholar]
  14. Miron D., Kenes J., Dagan R. Calves as a source of an outbreak of cryptosporidiosis among young children in an agricultural closed community. Pediatr Infect Dis J. 1991 Jun;10(6):438–441. doi: 10.1097/00006454-199106000-00004. [DOI] [PubMed] [Google Scholar]
  15. Simpson V. R. Cryptosporidiosis in newborn red deer (Cervus elaphus). Vet Rec. 1992 Feb 8;130(6):116–118. doi: 10.1136/vr.130.6.116. [DOI] [PubMed] [Google Scholar]
  16. Smith H. V., Patterson W. J., Hardie R., Greene L. A., Benton C., Tulloch W., Gilmour R. A., Girdwood R. W., Sharp J. C., Forbes G. I. An outbreak of waterborne cryptosporidiosis caused by post-treatment contamination. Epidemiol Infect. 1989 Dec;103(3):703–715. doi: 10.1017/s0950268800031101. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Sweitzer R. A., Ghneim G. S., Gardner I. A., Van Vuren D., Gonzales B. J., Boyce W. M. Immobilization and physiological parameters associated with chemical restraint of wild pigs with Telazol and xylazine hydrochloride. J Wildl Dis. 1997 Apr;33(2):198–205. doi: 10.7589/0090-3558-33.2.198. [DOI] [PubMed] [Google Scholar]
  18. Xiao L. Giardia infection in farm animals. Parasitol Today. 1994 Nov;10(11):436–438. doi: 10.1016/0169-4758(94)90178-3. [DOI] [PubMed] [Google Scholar]
  19. Xiao L., Herd R. P. Epidemiology of equine Cryptosporidium and Giardia infections. Equine Vet J. 1994 Jan;26(1):14–17. doi: 10.1111/j.2042-3306.1994.tb04323.x. [DOI] [PubMed] [Google Scholar]
  20. Xiao L., Herd R. P., McClure K. E. Periparturient rise in the excretion of Giardia sp. cysts and Cryptosporidium parvum oocysts as a source of infection for lambs. J Parasitol. 1994 Feb;80(1):55–59. [PubMed] [Google Scholar]

Articles from Applied and Environmental Microbiology are provided here courtesy of American Society for Microbiology (ASM)

RESOURCES