Can Kaposi sarcoma be prevented?

Kaposi sarcoma (KS) is caused by the Kaposi sarcoma herpesvirus (KSHV). There are no vaccines currently available to protect people against KSHV. For now, preventing KS depends on reducing the chance of becoming infected with KSHV and reducing the chance that people who are infected with KSHV will develop KS.

Most cases of KS in the United States occur in people with AIDS. Taking measures to avoid becoming infected with HIV could prevent most cases of KS in this country.

• Since HIV can be spread through sex, avoiding unprotected sex with people infected with HIV could help prevent these infections.
• Since many people don't know that they are infected with HIV, many public health workers recommend using a condom during any sexual contact. (A condom may not be needed if both people are HIV-negative and are in a mutually monogamous relationship). Abstinence is the most effective protection.
• Another way to become infected with HIV is to use contaminated (dirty) needles to inject recreational drugs. Many different public health and law enforcement solutions have been recommended.
• In the past, transfusions of blood and clotting factors were responsible for some HIV infections. As a result of improved HIV testing at blood banks, there is now a very low risk of HIV infection from blood products in the United States. In some poorer countries, blood products are not tested well, leading to a higher risk of HIV infection with transfusion in those countries.

Patients who are infected with HIV and KSHV, and take the right medicines can reduce their chance of developing KS.

• Testing for HIV can identify those infected with this virus. People with HIV should get treatment to help strengthen their immune system, which usually includes highly active antiretroviral therapy (HAART). HAART reduces the risk of people with HIV developing KS (and AIDS). In addition, treating infections that commonly occur in people with weakened immunity reduces the likelihood of developing problems with KS.
• KSHV is not tested for routinely, but tests are available that could be used to identify HIV-infected patients who are at risk for KS. Studies have shown that HIV-infected people who take several different drugs that block herpesvirus (ganciclovir or foscarnet) are less likely to develop KS because these drugs also work for KSHV. Still, these drugs have serious side effects, and they are only taken to treat certain infections, not to prevent KS.