HAV is found in feces (stool). People become infected when feces from a person who is infected with HAV enters their mouth. This may occur when food (including raw or undercooked shellfish) or water is contaminated with sewage; when an infected person handles food without washing his/her hands after using the bathroom; through oral-anal sex with an infected person (also known as rimming); and, rarely, from blood transfusions.
Some people with HAV -- especially children -- don't feel sick at all; others have symptoms including nausea, vomiting, diarrhea, fever, fatigue, rash, jaundice, liver pain, and dark brown urine. There is no treatment for HAV itself, but the symptoms can be treated.
HAV is not a chronic infection -- it goes away by itself, usually within two months. A person can be infected with HAV only once.
HBV can be found in blood, semen, and vaginal fluid of infected persons. Very small amounts of HBV have been found in breast milk and saliva. A person can get hepatitis B from sharing injection or tattooing equipment; from unprotected anal, vaginal, or oral sex; and from sharing personal care implements (such as toothbrushes and razors). HBV can be passed from mother to infant during childbirth.
A vaccine is available that protects against HBV infection. Every person with HIV or HCV should be vaccinated.
HBV can be treated with interferon and oral antiviral drugs, such as adefovir, entecavir, and telbivudine. Some HIV drugs are also active against HBV, such as lamivudine (3TC; Epivir), emtricitibine (FTC; Emtriva), and tenofovir (Viread).
As when treating HIV, antiviral HBV treatment should not be given as monotherapy to people with coinfection. Guidelines provide detailed information on drug choices for treating HBV and HIV. It is currently recommended that HIV treatment be started earlier, and include tenofovir plus either 3TC or FTC, plus at least one extra drug, so that there are at least three active drugs against HIV.
Another very important caution is that once HBV treatment is started, it should not be stopped unless the infection is completely cleared. This is because HBV treatment can cause a serious, sometimes fatal, flare of liver enzymes.
If HIV treatment needs to be changed, then the HIV drugs that are active against HBV should be maintained in the next regimen.
There is less research on HIV coinfection with these viral hepatitis infections:
Hepatitis D (HDV): a virus that only infects some people with hepatitis B. HDV increases the risk of cirrhosis and the rate of liver disease progression for people with HBV. A vaccination protecting against HBV also protects against HDV infection.
Hepatitis E (HEV): an infectious virus with characteristics similar to hepatitis A. HEV will clear without treatment over several weeks to months. There is no vaccine for HEV. You can be infected with this virus only once. It is not usually serious, except during pregnancy.
Hepatitis F (HFV): a virus thought to be similar to hepatitis B, but recent research has not confirmed this.
Hepatitis G (HGBV-C): a virus with structural similarities to hepatitis C. The role and importance of hepatitis G is unclear, especially in people with HIV. Some research suggests that hepatitis G may slow HIV progression. Other research suggests that clearing hepatitis G can make HIV more serious.