This article provides an exemplary account for en epidimiological tracing. While this is particularly about a rabies case in the Netherlands, this process and study can and should be applied to any sort of epidimiological investigation.
At the end of January, a rabid dog was imported from Morocco to the Netherlands. The puppy was acquired by a Dutch couple, who give an account for the progressive behavior change in the puppy. On February 14th, they contacted their local veterinary agency, explaining that they had both been bitten by the dog. A few days later, the puppy's behavior became uncontrollable, and it was euthanized by officials. Post-exposure prophylaxis was arranged for both of them, and all 43 contacts were informed and categorized into degree of exposure.
Why did this puppy manage to get imported, adopted, given a pet passport, etc. without any single person checking its rabies status? Illegal animal imports and bad veterinary practices continue to be the major cause for rabies showing up in Europe, where it is a common practice to adopt animals.