Some Facts About HIV / AIDS
Worldwide, the number of people with HIV numbers about 40 mil-lion, of that number, about 26 million lives in sub-Saharan Africa.
Worldwide, the number of people, ages 15 to 49 living with HIV, is 1.1%, but in sub-Saharan Africa the number is 8%.
In 2003, worldwide, the number of children under 18 orphaned by AIDS was 15 million, 12.3 million are located in sub-Saharan Africa
HIV-1 is thought to be carried by the sub-group of chimpanzees known as Pan troglodytes troglodytes (P. t. troglodytes), which were once common in west-central Africa.
HIV-2 corresponds to SIVsm, a strain of the Simian Immunodeficiency Virus found in the Sooty Mangabey (also known as the green monkey), which is indigenous to western Africa. SIV is also found in red-capped mangabeys and the greater spot-nosed monkeys and it is believed that chimps contracted SIV after they hunted, killed and eaten the two smaller species of monkey.
It is now generally accepted that HIV is a descendant of a Simian Immunodeficiency Virus (SIV). HIV-2 corresponds to SIVsm, a strain of the Simian Immunodeficiency Virus found in the sooty mangabey (the green monkey), which is indigenous to western Africa and the more virulent strain of HIV, namely HIV-1, is a close counterpart to SIVcpz, the SIV found in chimpanzees. So the current theory is that HIV is a descendant of a Simian Immunodeficiency Virus because certain strains of SIVs bear a very close resemblance to HIV-1 and HIV-2, the two types of HIV. The most commonly accepted theory is that of the 'hunter'. In this scenario, SIVcpz was transferred to humans as a result of chimps being killed and eaten or their blood getting into cuts or wounds on the hunter.
Researchers state that normally the hunter's body would have fought off SIV, but on a few occasions the virus adapted itself within its new human host and become HIV-1 and the fact that there were several different early strains of HIV, each with a slightly different genetic make-up (the most common of which was HIV-1 group M), appears to support the hunter theory because every time it passed from a chimpanzee to a man, it would have developed in a slightly different way (mutated) within his body, thus producing a slightly different strain.
Three of the earliest known instances of HIV infection occur in Africa. The evidence comes from a plasma sample taken in 1959 from an adult male living in what is now the Democratic Republic of Congo. A 1998 analysis of the plasma sample from 1959 has suggested that HIV-1 was introduced into the human population between the 1930s-40s, but no later than the early 1950s, However, there are some scientists who think that it may have entered the human population as early as the end of the 19th century.
It is believed that transmission outside of the African population occurred during the Guinea-Bissau’s war of independence from Portugal (1963-1974) because the first European cases of HIV-2 were discovered among Portuguese veterans of the war, many of whom had received blood trans-fusions, shared needles or syringes for injections following an injury, or had contact with African prostitutes in the region.
There is apparently a human gene mutation, "CCR-5-delta-32", which prevents the AIDS virus from taking over human cells. This discovery occurred when historians examined the reason why some individuals survived the Bubonic Plague during the Middle Ages. After collecting DNA samples from survivor descendents of the Plague, it was discovered that they all carried the CCR-5-delta-32 gene, a gene which prevents the plague bacteria from infecting the individual’s cells.
It appears that the Black Death strongly modified the European gene pool, increasing the frequency of CCR5-delta 32 because survivors of the Black Death had a higher frequency of the CCR5-delta 32 mutation.
Research on high-risk, HIV-negative individuals indicates that if they carry the CCR5-delta 32 gene from both parents, there is the possibility that they are immune to the disease. However, further research showed that that if a high risk HIV individual carries the gene from only one parent, they eventually came down with the HIV virus.
DNA samples from around the world show the presence of the CCR5 - delta 32 gene is highest in Europe (about 10% if the population are descendants of plague survivors) and in America, which was, for the most part, settled by European plague survivors. Only 2% of Central Asia’s population carries the gene and it is appears to be completely absent among East Asians, Africans, Latin Americans, and Native Americans.
I found all of this information on the web from a variety of sources.
