Researchers from the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH), announced that the identification of a specific HIV receptor that guides the virus to the intestines where it replicates and eventually destroys the body's lymph tissue.

"The identification of this new receptor opens up new avenues of investigation that may help further elucidate the complex mechanisms of the pathogenesis of HIV infection," says NIAID Director Anthony S. Fauci, M.D., chief of the Institute's Laboratory of Immunoregulation (LIR) and senior author of the new study, in a statement.

The researchers have found that the virus has a protein on its outer shell which binds with a specific receptor that guides the virus to the intestines, the integrin alpha-4 beta-7. This explains why the virus predominantly grows in the gut. Scientists have previously indentified three other main receptors, or molecular doorways, used by HIV to infect cells.

There are experimental drugs blocking the integrin alpha-4 beta-7 receptor, designed for the treatment of autoimmune disorders. Next it remains to be seen how useful they are in the treatment of HIV infections. Other scientists around the world praised the discovery as "an important advance in the field" of HIV studies.

The HIV virus can be transmitted by a mother pre-chewing the food for his baby, a practice that is spread mainly in poor, developing countries, U.S. government scientists said last week.

Two new studies released earlier this month have raised concerns about the current perceptions of HIV spread. A first study has raised doubts about earlier research which appeared to indicate the possibility that circumcision among men, which reduces their risk of infection from the HIV virus, could also benefit their female sexual partners. A second study has found that use of the drug acyclovir to treat people with genital herpes did not lower their risk of contracting HIV, as it was hoped previously.

Last month, the US Food and Drug Administration had approved etravirine tablets for the treatment of HIV patients. Etravirine, which will be sold under the trade name Intelence, was developed by Tibotec Pharmaceuticals, Ltd. The drug is a non-nucleoside reverse transcriptase inhibitor (NNRTI) that helps to block an enzyme which HIV needs to multiply and it was approved to be used in combination with other anti-HIV medications.

According to latest statistics released by WHO, 33 million people around the world are diagnosed to be living with HIV. The number seemed to have leveled off from 40 million worldwide which sounds promising but it still is a matter of great concern. Another 2.5 million people contracted the virus this year, which means a 40 percent lower than the estimate for 2006. Two million people more have died from AIDS in 2007.

The human immunodeficiency virus (HIV) is a retrovirus which eventually leads to the acquired immunodeficiency syndrome (AIDS). Infection with HIV occurs by the transfer of blood, semen, vaginal fluid, pre-ejaculate, or breast milk between an infected person and a healthy person. Unprotected sexual intercourse and contaminated needles are the top two infection paths.