there are no synthoms for hbv, hcv, cirrhosis, liver cancer, when there are synthoms in those situations one is close to death
there are specific synthoms on very few persons on acute hbv which clears in 95% of adults without liver damage, these synthoms are very general and not specific to hbv, fatigue, dark urine, yellow skin, itching, these are synthoms of low liver function and can be synthoms of many other illnesses related to liver not of hbv
the only way to know is a blood test for all hbv markers, check here:
http://www.medhelp.org/health_pages/Hepatitis/HepB-Introduction--Welcome-Page/show/34?cid=153
once the virus enters the body there is no real eradication but only immune control of it like for all viruses of hbv family (herpes for example), after decades few clear it complitely so if immune system is damaged by drugs (chemiotherapy etc) hbv infection developes again and very severe and often deadly.
there is no drug to eradicate hbv, they can only control replication, so it is smart to get vaccine at birth
it is very infectious and can be very easy to get especially in countries without vaccination at birth or soth america/asia