FYI: Just the Facts

AIDS

HIV (human immunodeficiency virus) is the virus that causes AIDS (acquired immune deficiency syndrome). HIV destroys cells that are crucial to the human immune system.

The Joint United Nations Program on HIV/AIDS estimates that out of the 40 million people living with HIV worldwide, 28.1 million dwell in Africa. The organization reports that 24 million people worldwide have died of AIDS. Although scientists have been able to slow replication of the virus, currently no cure exists.

Scientists have concluded that HIV arose from a virus in chimps, dubbed SIVcpz (simian immunodeficiency virus-chimpanzee).

Using one of the world's fastest supercomputers, scientists at Los Alamos National Laboratory in 2001 were able to analyze HIV-1, which has 11 subtypes. By keying in mutation rates of HIV and comparing the genetic makeup of these subtypes, researchers calculated that an ancestor common to the subtypes dates to about 1931.

"Patient 0," the first documented AIDS case in the United States, was identified in 1981. Early on, the illness was called GRID (Gay-Related Immune Deficiency). By the end of 1982, however, cases had spread to 14 nations worldwide; the first blood transfusion recipient was identified; and it was clear that GRID was also infecting male and female heterosexual drug users, Haitian refugees, and hemophiliacs. By the end of the year, the disease was renamed AIDS.

Dr. Robert Gallo developed a kit in 1985 for testing HIV antibodies in blood, to prevent giving "bad blood" to transfusion recipients.

AZT, the first approved drug therapy for HIV, greatly reduces its transmission from mother to child. It is given to HIV-positive pregnant women from the fourth month of pregnancy until the baby is born, and to the newborn baby for 6 weeks.

The AIDS virus often mutates, or changes its structure, leading doctors to recommend a "cocktail" of two or more drugs. The goal of such a treatment is to slow viral replication to undetectable levels.

GPO-Vir is the cheapest available drug cocktail. HIV-infected individuals who purchase the drugs at state hospitals in Thailand receive a month's worth of the generic single-pill three-drug treatment for $27--that's at least $87 less than the cost of the three drugs purchased separately.

Recent studies show that multiplication of the AIDS virus slows during acute bouts of measles--a surprise to researchers since the measles virus suppresses the immune system. Scientists at Johns Hopkins University expect this finding to lead to a better understanding of HIV's development and, possibly, to a treatment.

Scientists are one step closer to an edible vaccine to protect against HIV. The vaccine is made by genetically modifying corn to produce a key protein from the monkey form of HIV. Researchers hope that by triggering the production of antibodies that fight HIV infection, an edible vaccine would provoke a strong immune response in the parts of the body first exposed to HIV.

Researchers from the Contraceptive Research and Development Program in Arlington, Virginia, are modifying a contraceptive gel sold in Europe to make it effective in protecting against several sexually transmitted diseases, including HIV. The gel is expected to require at least six years of additional study.

A new study confirms what HIV researchers until now have only suspected: HIV selectively disables the immune system's response to the virus by disproportionately infecting the very cells designed to fight it. CD4+ T cells programmed to fight HIV are two to five times more likely to be infected with HIV than CD4+ T cells that are programmed to take on other pathogens.

--Compiled by Jenny Everett