Regional and Temporal Variations of Leptospira Seropositivity in Dogs in the United States, 2000–2010
Background Previous studies have reported a seasonal increased risk for leptospirosis, but there is no consistent seasonality reported across regions in the United States. Objectives To evaluate and compare seasonal patterns in seropositivity for leptospirosis in dogs for 4 US regions (northeast [NE...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2014-05-01
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| Series: | Journal of Veterinary Internal Medicine |
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| Online Access: | https://doi.org/10.1111/jvim.12335 |
| _version_ | 1811237676272058368 |
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| author | H.S. Lee M. Levine C. Guptill‐Yoran A.J. Johnson P. vonKamecke G.E. Moore |
| author_facet | H.S. Lee M. Levine C. Guptill‐Yoran A.J. Johnson P. vonKamecke G.E. Moore |
| author_sort | H.S. Lee |
| collection | DOAJ |
| description | Background Previous studies have reported a seasonal increased risk for leptospirosis, but there is no consistent seasonality reported across regions in the United States. Objectives To evaluate and compare seasonal patterns in seropositivity for leptospirosis in dogs for 4 US regions (northeast [NE], midwest [MW], south‐central [SC], and California‐southern west coast [CS]). Animals Forty four thousand nine hundred and sixteen canine serum samples submitted to a commercial laboratory for microscopic agglutination tests (MAT) from 2000 through 2010. Methods In this retrospective study, positive cases were defined as MAT titers ≥1 : 3,200 for at least one of 7 tested serovars. Four geographic regions were defined, and MAT results were included in regional analyses based on hospital zipcode. A seasonal‐trend decomposition method for times series was utilized for the analysis. Monthly variation in the seropositive rate was evaluated using a seasonal cycle subseries plot and logistic regression. Results Two thousand and twelve of 44,916 (4.48%) samples were seropositive. Compared to seropositive rates for February, significantly higher monthly rates occurred during the 2nd half of the year in the MW (OR 3.92–6.35) and NE (OR 2.03–4.80) regions, and only in January (OR 2.34) and December (OR 1.74) in the SC region. Monthly seropositive rates indicative of seasonality were observed earlier in the calendar year for both CS and SC regions. Conclusions and Clinical Importance Seasonal patterns for seropositivity to leptospires differed by geographic region. Although risk of infection in dogs can occur year round, knowledge of seasonal trends can assist veterinarians in formulating differential diagnoses and evaluation of exposure risk. |
| first_indexed | 2024-04-12T12:27:26Z |
| format | Article |
| id | doaj.art-3cadb02e43e84f159e200e7dd1e87886 |
| institution | Directory Open Access Journal |
| issn | 0891-6640 1939-1676 |
| language | English |
| last_indexed | 2024-04-12T12:27:26Z |
| publishDate | 2014-05-01 |
| publisher | Wiley |
| record_format | Article |
| series | Journal of Veterinary Internal Medicine |
| spelling | doaj.art-3cadb02e43e84f159e200e7dd1e878862022-12-22T03:33:07ZengWileyJournal of Veterinary Internal Medicine0891-66401939-16762014-05-0128377978810.1111/jvim.12335Regional and Temporal Variations of Leptospira Seropositivity in Dogs in the United States, 2000–2010H.S. Lee0M. Levine1C. Guptill‐Yoran2A.J. Johnson3P. vonKamecke4G.E. Moore5Department of Comparative Pathobiology Purdue University West Lafayette INDepartment of Statistics Purdue University West Lafayette INDepartment of Veterinary Clinical Sci‐ences Purdue University West Lafayette INDepartment of Comparative Pathobiology Purdue University West Lafayette INIDEXX Laboratories Westbrook MEDepartment of Comparative Pathobiology Purdue University West Lafayette INBackground Previous studies have reported a seasonal increased risk for leptospirosis, but there is no consistent seasonality reported across regions in the United States. Objectives To evaluate and compare seasonal patterns in seropositivity for leptospirosis in dogs for 4 US regions (northeast [NE], midwest [MW], south‐central [SC], and California‐southern west coast [CS]). Animals Forty four thousand nine hundred and sixteen canine serum samples submitted to a commercial laboratory for microscopic agglutination tests (MAT) from 2000 through 2010. Methods In this retrospective study, positive cases were defined as MAT titers ≥1 : 3,200 for at least one of 7 tested serovars. Four geographic regions were defined, and MAT results were included in regional analyses based on hospital zipcode. A seasonal‐trend decomposition method for times series was utilized for the analysis. Monthly variation in the seropositive rate was evaluated using a seasonal cycle subseries plot and logistic regression. Results Two thousand and twelve of 44,916 (4.48%) samples were seropositive. Compared to seropositive rates for February, significantly higher monthly rates occurred during the 2nd half of the year in the MW (OR 3.92–6.35) and NE (OR 2.03–4.80) regions, and only in January (OR 2.34) and December (OR 1.74) in the SC region. Monthly seropositive rates indicative of seasonality were observed earlier in the calendar year for both CS and SC regions. Conclusions and Clinical Importance Seasonal patterns for seropositivity to leptospires differed by geographic region. Although risk of infection in dogs can occur year round, knowledge of seasonal trends can assist veterinarians in formulating differential diagnoses and evaluation of exposure risk.https://doi.org/10.1111/jvim.12335DogsLeptospiraMicroscopic agglutination testsSeasonal cycle subseries plotSeasonal‐trend decomposition procedure based on loessSeropositive |
| spellingShingle | H.S. Lee M. Levine C. Guptill‐Yoran A.J. Johnson P. vonKamecke G.E. Moore Regional and Temporal Variations of Leptospira Seropositivity in Dogs in the United States, 2000–2010 Journal of Veterinary Internal Medicine Dogs Leptospira Microscopic agglutination tests Seasonal cycle subseries plot Seasonal‐trend decomposition procedure based on loess Seropositive |
| title | Regional and Temporal Variations of Leptospira Seropositivity in Dogs in the United States, 2000–2010 |
| title_full | Regional and Temporal Variations of Leptospira Seropositivity in Dogs in the United States, 2000–2010 |
| title_fullStr | Regional and Temporal Variations of Leptospira Seropositivity in Dogs in the United States, 2000–2010 |
| title_full_unstemmed | Regional and Temporal Variations of Leptospira Seropositivity in Dogs in the United States, 2000–2010 |
| title_short | Regional and Temporal Variations of Leptospira Seropositivity in Dogs in the United States, 2000–2010 |
| title_sort | regional and temporal variations of leptospira seropositivity in dogs in the united states 2000 2010 |
| topic | Dogs Leptospira Microscopic agglutination tests Seasonal cycle subseries plot Seasonal‐trend decomposition procedure based on loess Seropositive |
| url | https://doi.org/10.1111/jvim.12335 |
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