Combined cross-sectional and case-control study on Echinococcus multilocularis infection in pigs in Switzerland.

Meyer, Anika; Olias, Philipp; Schüpbach, Gertraud; Henzi, Martin; Barmettler, Thomas; Hentrich, Brigitte; Gottstein, Bruno; Frey, Caroline F. (2020). Combined cross-sectional and case-control study on Echinococcus multilocularis infection in pigs in Switzerland. Veterinary parasitology: X, 4, p. 100031. Elsevier 10.1016/j.vpoa.2020.100031

[img]
Preview
Text
b151410.pdf - Published Version
Available under License Creative Commons: Attribution-Noncommercial-No Derivative Works (CC-BY-NC-ND).

Download (5MB) | Preview

The canid tapeworm Echinococcus multilocularis causes alveolar echinococcosis (AE) in humans and other intermediate hosts. Depending on the permissiveness of the intermediate host, the larval form of E. multilocularis (metacestode) may be either fertile, e.g. in rodents, and thus supporting the life cycle of the parasite, or infertile, e.g. in pigs, and thus interrupting the life cycle. Pigs have been shown to act as aberrant hosts for the metacestode and consequently develop liver lesions but represent a dead-end for the parasite. Routine liver inspection at slaughter provided the basis for a large-scale surveillance study on E. multilocularis infection in pigs. The aim of this combined cross-sectional and case-control study was to estimate the minimal prevalence of E. multilocularis in pigs in Switzerland, to find factors associated with infection, and to assess potential regional clusters of infection. During the 12-month-study period, approximately 85% of all pigs slaughtered in Switzerland were assessed. In total, 450 pig livers with macroscopic lesions suggestive of E. multilocularis infection were analysed. Of those, 200 samples were positive by E. multilocularis-PCR. Thus, the overall minimal prevalence detected by molecular means was 0.009% in all slaughter pigs (200 of 2'143'996), 0.008% in finishing pigs (177 of 2'123'542), and 0.11% in breeding pigs (22 of 20'454). Histology revealed the unique presence of a laminated layer in 105 cases, and an additional germinal layer detected in a single case. Protoscoleces could not be observed in any of the lesions. Factors positively associated with infection were "foxes seen in the pig shed", "foxes on premises", "presence of other animals in the shed", "absence of a hygiene barrier", "outdoor feeding", "feeding grass", "lack of rodent control", "not having own dogs on the farm" and "infrequent deworming of sows". Infection was present in all regions sampled and was representative of the important pig rearing areas of Switzerland, without evidence of any obvious geographical cluster. Conclusively, our study provided further evidence of widespread environmental contamination with E. multilocularis eggs in Switzerland. Furthermore, the absence of protoscoleces in any of the lesions supported the concept that pigs act only as a dead-end host and thus do not contribute to the life cycle of the parasite. Factors associated with E. multilocularis infection were in-line with parasite biology, and many can be addressed by increasing hygiene and management standards.

Item Type:

Journal Article (Original Article)

Division/Institute:

05 Veterinary Medicine > Department of Infectious Diseases and Pathobiology (DIP) > Institute of Parasitology
05 Veterinary Medicine > Department of Clinical Research and Veterinary Public Health (DCR-VPH) > Veterinary Public Health Institute
05 Veterinary Medicine > Department of Infectious Diseases and Pathobiology (DIP) > Institute of Animal Pathology
05 Veterinary Medicine > Department of Infectious Diseases and Pathobiology (DIP)

UniBE Contributor:

Meyer-Schülke, Anika; Olias, Philipp Alexander; Schüpbach, Gertraud Irene; Hentrich, Brigitte; Gottstein, Bruno and Frey Marreros Canales, Caroline

Subjects:

500 Science > 570 Life sciences; biology
600 Technology > 630 Agriculture

ISSN:

2590-1389

Publisher:

Elsevier

Language:

English

Submitter:

Achim Braun Parham

Date Deposited:

25 Jan 2021 12:17

Last Modified:

24 Feb 2021 08:12

Publisher DOI:

10.1016/j.vpoa.2020.100031

PubMed ID:

32984810

Uncontrolled Keywords:

Echinococcus multilocularis alveolar echinococcosis case-control study liver risk factors slaughter pigs swine

BORIS DOI:

10.48350/151410

URI:

https://boris.unibe.ch/id/eprint/151410

Actions (login required)

Edit item Edit item
Provide Feedback