The association between natural drinking water sources and the emergence of zoonotic leptospirosis among grazing beef cattle herds during a human outbreak

Abstract

Leptospirosis is a zoonotic bacterial disease associated with water abundance in tropical and temperate climate zones. Bacterial spread may also occur in dry and warm weather conditions when humans and animals are forced to share depleted water sources. In such settings, farm animals such as beef cattle, which may be present in large numbers in natural water sources, can play a major role in disease spread. However, the risk factors for their infection and the potential control measures to prevent the disease spread have not been adequately studied. In the face of an emerging human leptospirosis outbreak in the dry and warm Israeli 2018 summer, we tested seropositivity to Leptospira serovar Pomona in grazing beef cattle and wild boars located in proximity to the contaminated streams. Additionally, we used the natural setting of the outbreak to identify risk factors for seropositivity in beef cattle. We found high seropositivity to serovar Pomona in grazing beef cattle (233/845), and in wild boars (7/13). Seropositivity was significantly associated with beef cattle drinking from natural water sources compared to beef cattle drinking from water troughs with fresh water supply (Multivariable logistic regression; odds ratio = 18.6, 95% confidence interval = 3–116, p -value<0.01). One Health approach is necessary for mitigating zoonotic Leptospira infections, in which interactions between humans, animals, and the environment play a major role. As the global warming crisis results in severe climate changes, dry and warm weather conditions may become more common worldwide. Under such conditions, reducing inter-species interactions in contaminated natural water sources is essential for protecting public health. Our study demonstrates the role of natural water as a source for beef cattle infection and disease spread. Furthermore, we suggest using water troughs with freshwater supply for preventing future outbreaks in animals and humans in such settings.

Epidemiology of Leptospira spp. infection in a beef cattle area of Argentina

“…For this reason, many studies have focused on sources and environmental risk factors to understand its epidemiology ( 22 , 25 ). Leptospira has been found in water and soil environments in rural and urban areas ( 26 , 27 ). Several factors are asociated for perpetuation of the bacteria, such as warm temperature, humid environments, neutral or slightly alkaline pH, and the presence of organic material ( 22 , 28 ).…”

“…Several factors are asociated for perpetuation of the bacteria, such as warm temperature, humid environments, neutral or slightly alkaline pH, and the presence of organic material ( 22 , 28 ). Consequently, surfe of water and animal overcrowding are likely to be important factors associated to leptospirosis outbreaks ( 27 , 28 ). Likewise, in this work, the models that explained Leptospira seropositivity were the presence of lagoons and upper soil environments—probably due to the effect of water drainage—and the being inside the spatial clusters.…”

Ocular leptospirosis: lack of awareness among ophthalmologists and challenges in diagnosis

“…Over 600 patients were suspected to get infected following recreational activities in natural pools in the Golan Heights. L. pomona and Leptospira balcanica were the causative serovars [28 ▪ ].…”

“…The spread may occur even in dry, warm weather specifically when humans and animals share limited water sources. An outbreak in cattle and wild boars was detected at the time of the human outbreak in which Leptospira pomona was detected in both groups [28 ▪ ] In 2018, a large outbreak of leptospirosis occurred in northern Israel. Over 600 patients were suspected to get infected following recreational activities in natural pools in the Golan Heights.…”

The risk level of water sources consumed community Baubau city: A geographic information system approach

“…Water sources that are not protected not only have an impact on humans but also have an impact on livestock. The role of natural water as a source of infection for livestock can cause the spread of disease, for daily purposes, it is advisable to use water tanks with a freshfreshwaterly to prevent future outbreaks in animals and humans [9].…”