Although acquired immune deficiency syndrome (AIDS) didn't hit mainstream collective consciousness until the early 1980s, new research out of the University of Arizona in Tucson indicates that the most pervasive global strain of human immunodeficiency virus (HIV) began spreading among humans between 1884 and 1924, a finding that suggests growing urbanization in colonial Africa set the stage for the HIV/AIDS pandemic.

Michael Worobey, an assistant ecology and evolutionary biology professor at Arizona, led the research, which studied a number of HIV-1 (the strain found in most cases outside of Africa) genetic sequences to determine the time periods when the virus genetically diverged from its predecessors. These findings, published in the current issue of Nature, were mapped out in the form of a family tree whose roots date back to the beginning of the 20th century.

The research, co-sponsored by the National Institute of Allergy and Infectious Diseases (NIAID), part of the U.S. National Institutes of Health, included a team of scientists from four continents who screened multiple tissue samples and uncovered the world's second-oldest genetic sequence of HIV-1 group M, which dates from 1960. The scientists used that, along with dozens of other previously known HIV-1 sequences, to construct a range of plausible family trees for this viral strain.

The scientists recovered the 48-year-old HIV gene fragments from a wax-embedded lymph node tissue biopsy from a woman in Kinshasa in the Democratic Republic of the Congo. The oldest known HIV-1 group M genetic sequence comes from a 1959 blood sample given by a Kinshasa man. A comparison between the same genetic regions of the 1959 and 1960 viruses provided additional evidence that their common ancestor existed around 1900.

Earlier estimates indicated that HIV first appeared in 1930, still well before most people had heard of either the virus or AIDS. today reported that the AIDS virus is infecting more women, heterosexual couples and gay men in China as the epidemic spreads from intravenous drug users to the general population, according to a study to be published Thursday in Nature.

Elsewhere, The Scripps Research Institute in La Jolla, Calif., Tuesday announced it has received a $30-million grant from the International AIDS Vaccine Initiative (IAVI), a large philanthropy in New York City, to create the world's only center dedicated to the "neutralizing antibody" approach, a promising way to develop an AIDS vaccine, according to The San Diego Union-Tribune's Web site. IAVI created the Neutralizing Antibody Consortium six years ago to address a neglected area of AIDS vaccine research and development, according to the La Jolla Light Web site.

(Image courtesy of iStockphoto; Copyright: Duncan Walker)