The Origins of HIV

Ignacio Romero

About our expert

Ignacio Romero took his position as Lecturer in Neuroscience at the Open University in 2000. Since then, he has taught OU courses in biological psychology and cell and molecular biology. His research is concerned with the roles of brain cells in immune reactions, in particular how brain cells interact with white blood cells in both health and disease, an interest that stems from his doctoral research at King’s College London. His more recent research focus on the biology of retroviruses and emerged from his postdoctoral position at the Cochin Institute in Paris in the late 1990s where he investigated how retroviruses such as HIV and HTLV enter the brain and cause neurological conditions. His work is carried out in vitro using culture systems designed to mimic the complex cellular environment of the human brain.

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Finally, we come to the question of the origin of HIV infection in humans. Very little is known about infection rates in humans before the 1970s, although some isolated cases of HIV infection have been detected in individuals that died in the 1950s and 1960s. A study that used complicated computational models of HIV evolution indicated that it was probably even earlier, in the 1930s, when the first human infections arose although this is far from certain. What we know is that HIV is similar to, and most probably descended from, another retrovirus that infects non-human primates. This retrovirus is called the simian immunodeficiency virus (SIV) and has been isolated from chimpanzees in West Africa. However, whether SIV crossed species in Africa or elsewhere (or indeed in several places and at different times) is unknown and would be difficult to prove.

Whatever its origin, our knowledge of how HIV infects and replicates in cells has steadily grown within the last 20 years and has allowed the enormous advances we have made to confront the AIDS pandemic. Dr Peter Piot, executive director of UNAIDS, optimistically summarized the outcome of this effort in the closure ceremony of this month’s XV International AIDS Conference in Bangkok:

"I truly believe that, for the first time, there is a real chance that we will get ahead of the epidemic. And this momentum has its roots in both the science and the activism of the last decades. But our challenge remains on how to raise action on both fronts to the level we need to achieve full success."