US Pharm. 2008:3(2):HS-34.

A study by a University of Arizona evolutionary biologist that was published in the Proceedings of the National Academy of Sciences uncovered that the AIDS virus was causing infections in the U.S. approximately 12 years before scientists officially recognized it as a disease in 1981. Lead researcher Michael Worobey said that the AIDS virus entered the U.S. from Haiti in around 1969.

Working with collected blood samples from early AIDS patients, the study investigators confirmed the entry date by conducting a genetic analysis of the human immunodeficiency virus (HIV). This allowed them to calibrate the molecular clock of the HIV strain that has spread most widely and to calculate when it first arrived in Haiti from Africa and then when it reached the U.S. Upon analysis, the researchers concluded that the virus was brought to Haiti by an infected person from central Africa in about 1966. It is believed that the virus circulated for years in the U.S. before symptoms of the infection became widespread.

To comment on this article, contact