Overview of HIV-2

HIV usually refers to the HIV-1 strain; but another strain, known as HIV-2, was first described in 1986 in West Africa. It is associated with the same opportunistic illnesses that result from HIV-1 infection; however, HIV-2 appears to have a milder and slower effect on the immune system. The mode of transmission is the same, although HIV-2 seems to be less transmissible from mother to child than HIV-1.

HIV-2 is predominantly restricted to West Africa, especially Cape Verde, Cote d'Ivoire (Ivory Coast), Gambia, Guinea-Bissau, Mali, Mauritania, Nigeria, and Sierra Leone. These nations reportedly have a higher than 1% prevalence rate in the general population, meaning that 1 out of every 100 people is infected with HIV-2. HIV-2 has spread through other West African nations, as well as outside of West Africa. Angola and Mozambique also have a higher than 1% prevalence rate. There are a very small number of HIV-2 cases in the United States, and testing for HIV-2 is not routinely done except in blood collection centers.

Risk Factors for HIV-2

According to the Centers for Disease Control and Prevention (CDC), the following factors increase the risk for contracting HIV-2:

  • Having a sex partner from a country where HIV-2 is endemic
  • Having a sex partner known to be infected with HIV-2
  • Receiving a blood transfusion or nonsterile injection in a country where HIV-2 is endemic
  • Sharing needles with an infected person or someone who is from a country where HIV-2 is endemic
  • Being born to a mother with a risk factor or who has HIV-2 infection

Although the CDC does not recommend routine testing for HIV-2 in the United States, it is recommended that if a person who has any of the above risk factors is tested for HIV-1, he or she should also be tested for HIV-2. Blood donations are regularly tested for both HIV-1 and HIV-2.

Others who should be tested for HIV-2 include people who have AIDS-like symptoms but test negative for HIV-1 and people who have certain indeterminate HIV-1 test results.

Treatment for HIV-2

According to the Centers for Disease Control and Prevention (CDC), it is not clear whether or to what extent the potential benefits of antiretroviral therapy outweigh the possible side effects regarding HIV-2. Laboratory studies suggest that nucleoside analogs are active against HIV-2, but are not as active as when fighting HIV-1.

Publication Review By: Stanley J. Swierzewski, III, M.D.

Published: 01 Dec 2000

Last Modified: 01 Dec 2011