Tags

Type your tag names separated by a space and hit enter

Seroprevalence and herd-level risk factors for seroprevalence of Leptospira spp. in sheep, beef cattle and deer in New Zealand.
N Z Vet J 2018; 66(6):302-311NZ

Abstract

AIMS To determine seroprevalence of Leptospira borgpetersenii serovar Hardjo and L. interrogans serovar Pomona in beef cattle, sheep and deer in New Zealand and the association between farm-level risk factors and seroprevalence.

METHODS

Between June 2009 and July 2010, 20 serum samples per flock or herd were collected from 162 sheep flocks, and 116 beef cattle and 99 deer herds from 238 farms, along with farm data by interview. Samples were tested for antibodies to serovars Hardjo and Pomona by microscopic agglutination testing, with a titre ≥48 being positive. Species-specific associations between herd-level seroprevalence (number of seropositive animals, for each serovar, divided by the number of animals tested) and herd-level risk factors were determined by multivariable logistic regression analysis. Vaccinated animals were excluded from seroprevalence estimates but included in multivariable analyses.

RESULTS

For sheep (n=3,339), animal-level seroprevalence was 43.6 (95% CI=41.9-45.3)% for serovar Hardjo and 14.1 (95% CI=12.9-15.3)% for serovar Pomona; for beef cattle(n=1,886), it was 45.6 (95% CI=43.3-47.9)% for Hardjo and 19.6 (95% CI=17.9-21.5)% for Pomona; and for deer (n=1,870), it was 26.3 (95% CI=24.3-28.4)% for Hardjo, 8.8 (95% CI=7.6-10.2)% for Pomona. In sheep flocks (n=161), flock-level prevalence for Hardjo varied from 77.9-91.3%, and for Pomona from 40.4-73.9%, when ≥1, ≥2 or ≥3 animals were seropositive. In beef herds (n=95), herd-level prevalence for Hardjo varied from 79.0-90.5%, and for Pomona from 42.1-68.4%. In deer herds (n=93), herd-level prevalence for Hardjo varied from 45.2-59.1%, and for Pomona from 22.6-48.4%. For sheep flocks, herd-level seroprevalence for Hardjo was associated with flock size (OR=1.56) and number of dogs (OR=0.75), and for Pomona, seroprevalence varied with region. For beef cattle, herd-level seroprevalence for Hardjo was associated with herd size (OR=1.4), presence of dams (OR=0.6) and vaccination (OR=2.9), and for Pomona, co-grazing with deer (OR=0.4), vaccination (OR=3.22), presence of dams (OR=0.2) and streams (OR=2.7). For deer herds, seroprevalence for Hardjo or Pomona was associated with herd size (OR=1.6 and 1.8) and varied with region, and for Pomona seroprevalence varied with season (summer vs. winter: OR=4.8).

CONCLUSIONS

Serovars Hardjo and Pomona were highly prevalent at herd and animal levels, with serovar Hardjo highest in all species. Larger herd size was the common risk factor for seroprevalence in all livestock species.

Authors+Show Affiliations

a Section of Epidemiology, Vetsuisse Faculty , University of Zurich , Zurich , Switzerland. b Department of Medicine , Swiss Tropical and Public Health Institute and University of Basel , Basel, Switzerland.c School of Veterinary Science , Massey University , Private Bag 11222, Palmerston North , 4412 , New Zealand.c School of Veterinary Science , Massey University , Private Bag 11222, Palmerston North , 4412 , New Zealand.c School of Veterinary Science , Massey University , Private Bag 11222, Palmerston North , 4412 , New Zealand.d Preventive Veterinary Medicine Institute , Austral University of Chile , Valdivia , Chile.c School of Veterinary Science , Massey University , Private Bag 11222, Palmerston North , 4412 , New Zealand.

Pub Type(s)

Journal Article

Language

eng

PubMed ID

30122123

Citation

Dreyfus, A, et al. "Seroprevalence and Herd-level Risk Factors for Seroprevalence of Leptospira Spp. in Sheep, Beef Cattle and Deer in New Zealand." New Zealand Veterinary Journal, vol. 66, no. 6, 2018, pp. 302-311.
Dreyfus A, Wilson P, Benschop J, et al. Seroprevalence and herd-level risk factors for seroprevalence of Leptospira spp. in sheep, beef cattle and deer in New Zealand. N Z Vet J. 2018;66(6):302-311.
Dreyfus, A., Wilson, P., Benschop, J., Collins-Emerson, J., Verdugo, C., & Heuer, C. (2018). Seroprevalence and herd-level risk factors for seroprevalence of Leptospira spp. in sheep, beef cattle and deer in New Zealand. New Zealand Veterinary Journal, 66(6), pp. 302-311. doi:10.1080/00480169.2018.1507770.
Dreyfus A, et al. Seroprevalence and Herd-level Risk Factors for Seroprevalence of Leptospira Spp. in Sheep, Beef Cattle and Deer in New Zealand. N Z Vet J. 2018;66(6):302-311. PubMed PMID: 30122123.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Seroprevalence and herd-level risk factors for seroprevalence of Leptospira spp. in sheep, beef cattle and deer in New Zealand. AU - Dreyfus,A, AU - Wilson,P, AU - Benschop,J, AU - Collins-Emerson,J, AU - Verdugo,C, AU - Heuer,C, Y1 - 2018/09/16/ PY - 2018/8/21/pubmed PY - 2018/11/13/medline PY - 2018/8/21/entrez KW - Hardjo KW - Leptospira KW - Pomona KW - beef cattle KW - deer KW - leptospirosis KW - risk factors KW - seroprevalence KW - sheep SP - 302 EP - 311 JF - New Zealand veterinary journal JO - N Z Vet J VL - 66 IS - 6 N2 - AIMS To determine seroprevalence of Leptospira borgpetersenii serovar Hardjo and L. interrogans serovar Pomona in beef cattle, sheep and deer in New Zealand and the association between farm-level risk factors and seroprevalence. METHODS Between June 2009 and July 2010, 20 serum samples per flock or herd were collected from 162 sheep flocks, and 116 beef cattle and 99 deer herds from 238 farms, along with farm data by interview. Samples were tested for antibodies to serovars Hardjo and Pomona by microscopic agglutination testing, with a titre ≥48 being positive. Species-specific associations between herd-level seroprevalence (number of seropositive animals, for each serovar, divided by the number of animals tested) and herd-level risk factors were determined by multivariable logistic regression analysis. Vaccinated animals were excluded from seroprevalence estimates but included in multivariable analyses. RESULTS For sheep (n=3,339), animal-level seroprevalence was 43.6 (95% CI=41.9-45.3)% for serovar Hardjo and 14.1 (95% CI=12.9-15.3)% for serovar Pomona; for beef cattle(n=1,886), it was 45.6 (95% CI=43.3-47.9)% for Hardjo and 19.6 (95% CI=17.9-21.5)% for Pomona; and for deer (n=1,870), it was 26.3 (95% CI=24.3-28.4)% for Hardjo, 8.8 (95% CI=7.6-10.2)% for Pomona. In sheep flocks (n=161), flock-level prevalence for Hardjo varied from 77.9-91.3%, and for Pomona from 40.4-73.9%, when ≥1, ≥2 or ≥3 animals were seropositive. In beef herds (n=95), herd-level prevalence for Hardjo varied from 79.0-90.5%, and for Pomona from 42.1-68.4%. In deer herds (n=93), herd-level prevalence for Hardjo varied from 45.2-59.1%, and for Pomona from 22.6-48.4%. For sheep flocks, herd-level seroprevalence for Hardjo was associated with flock size (OR=1.56) and number of dogs (OR=0.75), and for Pomona, seroprevalence varied with region. For beef cattle, herd-level seroprevalence for Hardjo was associated with herd size (OR=1.4), presence of dams (OR=0.6) and vaccination (OR=2.9), and for Pomona, co-grazing with deer (OR=0.4), vaccination (OR=3.22), presence of dams (OR=0.2) and streams (OR=2.7). For deer herds, seroprevalence for Hardjo or Pomona was associated with herd size (OR=1.6 and 1.8) and varied with region, and for Pomona seroprevalence varied with season (summer vs. winter: OR=4.8). CONCLUSIONS Serovars Hardjo and Pomona were highly prevalent at herd and animal levels, with serovar Hardjo highest in all species. Larger herd size was the common risk factor for seroprevalence in all livestock species. SN - 1176-0710 UR - https://www.unboundmedicine.com/medline/citation/30122123/Seroprevalence_and_herd_level_risk_factors_for_seroprevalence_of_Leptospira_spp__in_sheep_beef_cattle_and_deer_in_New_Zealand_ L2 - http://www.tandfonline.com/doi/full/10.1080/00480169.2018.1507770 DB - PRIME DP - Unbound Medicine ER -