Hiv/aids

Abstract HIV is the virus that causes acquired immunodeficiency syndrome, or AIDS. It is transmitted by the exchange of bodily fluids. Untreated HIV infections are usually fatal within five to 10 years, but people with AIDS die from opportunistic infections, rather than from HIV itself. HIV uses its surface protein gp120 to enter immune cells; a mutation in the human genome called CCR5-Δ32 blocks this mechanism of entry. HIV’s rapid replication, mutation, and recombination rates make it highly evolvable and thus very hard to treat, cure, or prevent via vaccine. Despite these challenges, a regimen of highly active anti-retroviral therapies (HAART), developed in the mid-1990s, is extraordinarily effective against HIV, and is now being used preventively as well. While researchers have used extraordinary efforts to cure a handful of people of HIV, large-scale efforts to control HIV depend on education, condom use, needle exchange, pre-exposure prophylaxis, and HAART. Phylogenetic and historical analyses show that the ancestor of HIV first jumped from chimpanzees to humans in Africa in the early 20th century; some combination of colonial practices, use of non-sterilized syringes, and changing sexual practices then spread the virus throughout Africa and worldwide.