So the whole idea about avoiding Hepatitis B is flawed. It is so infectious and the best way is to get a vaccine which is alot lot lot cheaper than managing/controlling the disease.
I think the whole idea with Hepatitis B is not to prevent from having it. Because most person throughout his life is affected by Hepatitis B.
Some person would be infected and develop a natural antibody to Hepatitis B, and clear the virus. This is called acute.
While others like me, are borned with Hepatitis B, so I am carrier because the virus is present for 6 month or more and I dont have antibody to hepatitis. This is called chronic.
So if your HBsAg is -negative, then get a hepatitis B vaccine if your HBs Ab antibody is low.
I read about this as well in a book
The First Year---Hepatitis B: An Essential Guide for the Newly Diagnosed
The probability is small but here how a person may catch Hepatitis B
Using the hair brush / razor the brush may have picked up traces of blood from wound in the scalp. The blood may be transferred to the next person if that person has scalp wound as well.
This method i think apply as well to blood - transferred disease. So best to be safe than sorry.
Hepatitis B virus was mentioned in the book, to have ability to survive outside living host for almost a week. which make it more contagious than HIV.
Unfortunately the damage / outcome of Hepatitis B to health is felt in relatively long future so people become ignorant of it.