Hotspots of canine leptospirosis in the United States of America

Abstract

Leptospirosis is a widespread zoonotic disease that causes hepatic and renal disease in dogs and human beings. The incidence of leptospirosis in dogs in the USA appears to be increasing. This study used 14 years of canine leptospirosis testing data across 3109 counties in the USA to analyze environmental and socio-economic correlates with rates of infection and to produce a map of locations of increased risk for canine leptospirosis. Boosted regression trees were used to identify the probability of a dog testing positive for leptospirosis based on microscopic agglutination test (MAT) results, and environmental and socio-economic data. The Midwest, East and Southwest were more likely to yield positive tests for leptospirosis, although specific counties in Appalachia had some of the highest predicted probabilities. Location (suburban areas or areas with deciduous forest) and climate (precipitation and temperature) were predictors for positive MAT results for leptospirosis, although the precise direction and strength of the effects was difficult to interpret. Wide geographic variation in predicted risk was identified. This risk mapping approach may provide opportunities for improved diagnosis, control and prevention of leptospirosis in dogs.

City sanitation and socioeconomics predict rat zoonotic infection across diverse neighbourhoods

“…(1996) similarly suspected Leptospirosis transmission to involve contact with rat urine in urban alleys in Baltimore, MD. In addition to humans, domestic dogs can contract Leptospirosis from contact with contaminated water (White et al., 2017), and so alleys with enough standing water to warrant complaints may be hotspots for transmission between people, domestic animals, and wildlife. In fact, the prevalence of Leptospira spp.…”

“…In fact, the prevalence of Leptospira spp. infection has been increasing for Chicago dogs (White et al., 2017), suggesting a potential concomitant increase in exposure for urban residents. In these instances, mitigation efforts might aim to identify and resolve standing water issues to minimize Leptospira spp.…”

Leptospiral shedding and seropositivity in shelter dogs in the Cumberland Gap Region of Southeastern Appalachia

“…The prevalence of canine leptospirosis is increasing throughout the US, but some regions are considered hotspots of leptospirosis due to disproportionately large clusters of cases [7,8,9,10,11,12]. The Cumberland Gap Region (CGR), located close to the intersection of the state boundaries of Kentucky, Tennessee, and Virginia, is primarily a rural area that has all climatic, topographical, and socioeconomic factors that have been described as risk predictors for the occurrence of leptospirosis [13]. In a previous study, canine leptospirosis testing data collected over a period of 14 years in the United States was analyzed to develop predictive models for identifying regions of increased risk for leptospirosis.…”

“…In that study, several counties in Appalachia had predictive probabilities for dogs testing seropositive. But the CGR was underrepresented in the testing data, likely due to the poor socio-economic status of the communities and a lack of veterinary care for pets in this region [13].…”

Households as hotspots of Lassa fever? Assessing the spatial distribution of Lassa virus-infected rodents in rural villages of Guinea

“…food storage, waste disposal, building materials, presence of pets) are unevenly distributed in the environment, focal clusters or hotspots of disease transmission can occur, defined as areas of elevated transmission efficiency and spillover risk [3]. Examples of zoonotic diseases that cluster in the human environment are leptospirosis, rabies, West Nile fever and bubonic plague [4][5][6]. Hotspot detection is important to understand the drivers of disease transmission and has successfully increased the cost-effectiveness of control programs [7,8].…”