How did your Vet diagnose this condition? Was that through blood samples? My dog was diagnosed with this same problem and he was put on medicines for 2 weeks. He recuperated quite well. It depends on how early we take action. This disease is not contagious to humans and hence you need not worry. In fact, there are very few diseases that can affect humans-beings from dogs and the vaccination for them are available. These disease are more animal to animal than animal to humans.
As far a liver is concerned, I'm sure your Vet must have prescribed some supplements to make the Liver stronger again. Usually, they prescribe liver tonics which work quite well.
Some important things that you need to do is - seek your vet's suggestion as to when you can put anti-tick/flees collar on your dog. Since, the dog is undergoing treatment, I'd not suggest you to do that now but when your vet permits you can put an anti-tick collar around your dog's neck which will protect him against flees/ticks in future.
Secondly, you may have to start anti-tick treatment on your dog depending on how severe the infection is. The Vet will be your POC. Some very basic things that you can follow- Maintain cleanliness around your house, don't let your dog play with infected animals, don't let your dog play in grassy surface. Most importantly, never let your dog go outside without the leash. Always, keep your dog in the leash as a responsible owner.