I frequently get questions indicating some misunderstanding about the different types of hepatitis and HIV, and have selected this question to try to clarify the situation.
Hepatitis is a term meaning inflammation of the liver. There are many diseases which can cause a hepatitis, including some that are not even infectious, like sarcoid. Infections that can lead to hepatitis can be bacterial, like syphilis, fungal, like histoplasmosis, parasitic like amebic hepatitis, or viral, like the three diseases you mentioned.
When someone says they have hepatitis however, they are usually referring to one of the three most common types of viral hepatitis, hepatitis A, B, or C. These three viral causes of hepatitis are totally different viruses, and these viruses never change into one another. Therefore, if someone has been infected with the hepatitis A virus, which is spread through food and water, it may make them very ill, but tests will show that they have been infected only with the hepatitis A virus. These tests will usually remain positive for the rest of that person’s life, and will never change to show hepatitis B or C unless the person becomes infected with one of those other viruses. Having had hepatitis A makes one immune to catching it again.
The hepatitis B and C viruses act totally differently. They are not spread through food and water, but through blood, blood products and needle sharing among drug users. Hepatitis B is commonly spread sexually; hepatitis C is occasionally but not often spread in that way. Hepatitis B often makes you sick when you are first infected, whereas hepatitis C seldom makes people sick with the initial infection, and most people with hepatitis C are surprised to be told that they have it.
Both hepatitis B and C, but not A, have the ability to become chronic infections. That is to say they are able to hide from our bodies’ immune system and continue to live within the liver cells. In adults, only about six percent of people infected with type B go on to become chronic cases, but about 85 percent of those infected with type C become chronic. This may be due to the fact that the hepatitis C virus undergoes frequent mutations, changing the proteins that make it up, and thereby evading the antibodies produced by our immune system.
A person can be infected with all three of the hepatitis viruses, but they are all separate infections usually acquired at separate times. I have seen a few patients who have had all three, and many who have had both B and C.
Neither hepatitis B nor C can turn into the human immunodeficiency virus. HIV is transmitted in the same ways as hepatitis B and C; therefore, it is pretty common to have patients with HIV who also have hepatitis B or C. The most common mode of transmission of HIV now in the United States is through intravenous drug use — the sharing of needles — and this is also a perfect way to transmit either hepatitis B or C. Therefore, in my practice, I would estimate that about 50 percent of my HIV-positive patients are also infected with hepatitis C. Many have also had hepatitis B, but since only about six percent of adults develop the chronic form of the disease, they usually no longer have an active infection by that virus.
HIV infection in someone also infected with hepatitis C appears to make the hepatitis progress more rapidly. It may also complicate the treatment of the HIV infection, since many of the potent anti-HIV drugs can be toxic to the liver, and this may be a problem if the person already has a liver damaged by hepatitis C.
The clear answer to your question is: No, hepatitis B cannot turn into hepatitis C, and neither of them can turn into HIV or AIDS. However, the same person can be infected with any two or all three of the viruses, since they are transmitted in the same ways. Sharing needles to inject drugs often results in infection with more than one of these viruses, since injecting them into your bloodstream is the most efficient way of spreading all three. This is the major reason, in my opinion, why free needle exchange programs aimed at drug users are so important to reduce the spread of these infections.