Using Technology to Track Disease

Scientists studying disease outbreaks in humans sometimes use specialized mapping programs to see if the spread of the illness can be explained by proximity to a common disease source. This type of disease mapping can be an extremely useful tool in controlling outbreaks as well as preventing future clusters of disease. In fact, many scientists consider the field of epidemiology to have begun with just such a study when John Snow mapped a 1854 cholera outbreak taking place in London, realized most cases were near the Broad street water pump, lobbied for the removal of the pump handle, and stopped the devastating disease in its tracks.

However, disease mapping isn’t only a tool for humans. It can also be used to improve the understanding of canine illness. One condition that has been studied this way is leptospirosis. Leptospirosis, which is caused by a waterborne parasite, can infect both dogs and humans. That makes it a research priority, as does its severity in the canine population. Without effective treatment, it can cause serious kidney and liver damage. It can even lead to death.

With help from the AKC Canine Health Foundation, researchers from the University of California-Davis have been investigating the spread of leptospirosis in Northern California. Previous research has identified the area as a potential hot spot of disease, and the scientists hope that detailed mapping of cases may make it easier to direct both education and prevention efforts. There is a vaccine for leptospirosis, but it is not a standard part of canine care. It also only protects against a subset of the more than 200 types of leptospirosis parasite found in nature, and so it may not always be the most effective mode of prevention.

In a study published in the April 2013 issue of the Journal of the American Veterinary Medical Association, the researchers found that leptospirosis cases seen in Northern California were indeed clustered together geographically. They compared infected dogs with other dogs seen at the same veterinary hospital where the study was being performed, and the leptospirosis cases lived significantly closer to one another than did the control dogs. This allowed the scientists to identify a residential area where dogs were at relatively high risk for leptospirosis, an area where improved vaccination coverage and other preventative efforts might best be focused.

Using geographical information systems to map human and canine disease has been getting easier ever year. Software for performing such analysis has become more affordable and simpler to use, as have many of the options used for mapping locations into such systems. Hopefully, as this technological trend continues, more and more scientists will consider using such tools to track disease. Doing so does not only provide important information about the state of human and animal health. It can also help keep all of us healthier in the future by allowing professionals to focus prevention programs on the highest risk areas. For example, veterinarians in the high risk zone might also be encouraged to spend more time discussing the risks of drinking from puddles and other standing water sources with their patients, particularly during an ongoing outbreak.

This work was funded by AKC Canine Health Foundation grant 1480.

Publication:

Spatial and temporal patterns of Leptospira infection in dogs from northern California: 67 cases (2001–2010, Janemarie H. Hennebelle, DVM, MPVM; Jane E. Sykes, BVSc, PhD, DACVIM; Tim E. Carpenter, PhD; Janet Foley, DVM, PhD; Journal of the American Veterinary Medical Association, April 1, 2013, Vol. 242, No. 7, Pages 941-947