I know gonorrhea, syphilis, and chlamydia are curable. There is a series of three vaccinations that will make it unlikely that you will contract Hepatitis B. Hepatitis C and D are not so simple. They are both STDs just like B, and they can eventually cause liver failure. Eh, after doing a bit of reading, there is actually a treatment, though I suspect that it's expensive. The treatment includes two anti-viral drugs, Pegylated interferon alpha and ribavirin. Treatment can take months... like 6 months to close to a year. Thus, it can be "cleared", but it takes a long time. My guess is that the disease is still present but dormant. Permanent liver damage is likely. Still, there are those resistant genotypes of the disease and people who do not respond to treatment. It's simply better not to get it. Early treatment is key otherwise before permanent liver damage and even death occur. It's not at all pleasant. I've seen someone in an acute phase. He was quite sick from it. The treatments seem to be new, because even a few years ago, there was nothing that could stop the disease completely, or clear it for that matter.
http://www.cdc.gov/hepatitis/HepatitisC.htm