Theory 3: Natural Transfer There are several theories that fall into this category that I will discuss here.  These ideas depend upon the assumption that the hypothesis that AIDS is an old disease that has gone unrecognized for years is true, and the fact that the epicenter of the AIDS pandemic lies in Africa. The two most widely accepted theories that I will describe are the isolated tribe theory and the monkey as food theory.  Both of these theories have scientific merit, but neither has been proven (nor irrefutably disproved) thus far. Isolated Tribe Theory: HIV could have been transferred from primate to human in an isolated tribe many years ago deep in the jungles of Africa, but because of the traditional mores and stigmas against sexual promiscuity it would have been possible for the virus to be seldom transferred from human to human.  Typical AIDS symptoms include tuberculosis, pneumonia, wasting, and fever. If the disease were to be contracted and cause sickness and death, it could have likely gone unrecognized as significant, and most likely unrecorded, in a rural area without advanced medical facilities.  The opening of the interior of Africa by roadway, railway and riverboats after colonization promoted mass migration and urbanization.  The newly available access to needles and syringes, often unsterilized between uses, took place at an almost simultaneous time to urbanization.  These changes in travel means could have brought a disease out of a rural area into the general population and transmitted from person to person via sexual contact.  The practice of using unsterilized medical equipment was, at this time, still quite common in Africa. HIV could easily have been transmitted from one infected person to dozens of healthy individuals via an infected needle. Monkey as Food Theory: Eating the meat of monkeys is a common practice for millions of Africans.  AIDS could have been transferred through eating uncooked monkey meat, or meat that was not cooked at sufficient temperatures to destroy the virus.  The disease also could have been transferred from monkey to hunter through biting and scratching during capture, or from monkey to human through the skinning and cooking process (assuming the person preparing the monkey for food had small cuts on their hands for the monkey blood to enter into).  There are two possible primates for use in this theory that are known to carry the SIVs closest to HIV.  They are the chimpanzee (cpz) and the sooty mangabey (sm) and they inhabit the correct areas of Africa (more or less) to correlate with HIV-1 and HIV-2 outbreaks.  Both species are also known to be, or have been, commonly hunted for food. Both of these theories seem like they could be very possible, at least on the surface, but there are several reasons we cannot accept them as truth at face value. ? The fact that both the chimpanzee and sooty mangabey seem to live very comfortably with SIV and do not go on to get AIDS suggests that the virus has been present in their species for quite some time and they have had time to adapt to it.  Both HIV-1 and HIV-2 cause AIDS in humans, which means that, more than likely, the disease is new to homosapiens and has not yet found a balance within the host. It can most definitely be assumed that hunting and eating monkeys has been practiced in Africa for thousands of years.  So why did HIV transfer from primates only recently, and twice in the span of a few years in separate areas of the continent in the second half of the 1900’s? ? Of the rural tribes that fit the isolated tribe theory, only few are acceptable candidates to have started the migration of the disease throughout Africa. These few tribes are the ones who live in close proximity to, and are known to hunt and eat the two specific types of primate who’s SIVs are closest to the two HIVs.  The most prime example of one such group is the pygmy tribe, but in an article written for a scientific journal called the Lancet in 1986 it was documented that this particular tribe did not come into contact with HIV until years after the start of the epidemic.  ? Several doctors who worked in the Congo prior to the start of the AIDS epidemic have stated that diseases that are, in most cases, considered to be rare but are common opportunistic infections in AIDS patients were not seen in the Congo prior to the 1960’s, even among the isolated tribes. ? Steam ships have been travelling the Congo River from Kinshasa to Kisangani (cities in the Congo, the apparent epicenter of HIV-1) since the 1880’s.  River ferries have been travelling through remote parts of the interior of the Congo since 1910.  Even if the tribes mentioned above lived in extremely remote areas, is it possible that no member of that tribe ever had contact with someone outside their group until the 1970’s (within the period of time necessary to transmit HIV and begin an epidemic outside of their tribe’s area)? ? A graph of HIV infection in Kinshasa from 1959-1970 and 1980 showed a steady increase throughout those years.  A steadily increasing rate of infection over such a time span indicates that a newly arrived virus in humans was taking hold in the population, rather than that a sudden increase in an age-old disease somehow began.