Investigation of spatio-temporal clusters of positive leptospirosis polymerase chain reaction test results in dogs in the United States, 2009 to 2016.
J Vet Intern Med 2021;
35:1355-1360. [PMID:
33729616 PMCID:
PMC8163129 DOI:
10.1111/jvim.16060]
[Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 01/22/2021] [Accepted: 01/27/2021] [Indexed: 11/28/2022] Open
Abstract
Background
Leptospirosis is a zoonotic disease of concern and an investigation of recent spatio‐temporal trends of leptospirosis in dogs in the United States is needed. Leptospira PCR testing has become increasingly used in veterinary clinical medicine and these data might provide information on recent trends of disease occurrence.
Objectives
To identify and describe clusters of PCR‐positive Leptospira test results in dogs in the United States.
Animals
Leptospira real‐time PCR test results from dogs (n = 40 118) in the United States from IDEXX Laboratories, Inc., between 2009 and 2016 were included in the analysis.
Methods
In this retrospective study, spatio‐temporal clusters for a real‐time PCR‐positive test were identified using the space‐time permutation scan statistic and the centroid of the zip code reported for each test. A maximum spatial window of 20% of the population at risk, and a maximum temporal window of 6 months were used.
Results
Seven statistically significant space‐time clusters of Leptospira real‐time PCR‐positive test results were identified across the United States: 1 each located within the states of Arizona (2016), California (2014‐2015), Florida (2010), South Carolina (2015), and 1 each located within the south‐central region (2015), midwest region (2014), and northeast region (2011). Clusters ranged from 3 to 108 dogs and were identified during all years under study, except 2009, 2012, and 2013.
Conclusions and Clinical Importance
The spatial and temporal components of leptospirosis in dogs in this study are similar to those in previous work. However, clusters were identified in new areas, demonstrating the complex epidemiology of this disease.
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