Genetic Evidence Exonerates HIV’s “Patient Zero”

Gaeten Dugas, the man who received the title “Patient Zero” for supposedly bringing HIV/AIDS into the United States, has been cleared.  Dugas was a Canadian flight attendant who contracted and died of AIDS soon after the disease first appeared in the US.  The book And the Band Played On paints a sinister picture of his role in the early AIDS epidemic, leading many to suspect that Dugas singlehandedly brought HIV and AIDS to the North American continent.

A recent study in the journal Nature, however, debunks this speculation.  An international team of scientists screened thousands of blood samples from the 1970s, found several that contained HIV, and studied the viral genetic material contained in eight separate samples.  After comparing these viral genomes to that of Dugas’ infection, the researchers found no evidence that Dugas was the first person in North America to be infected with HIV.

The success of this study revolves around HIV’s high mutation rate.  The human immune system is typically very good at recognizing and destroying viruses, but because HIV’s genetic material is constantly changing, the virus eventually stumbles upon a mutation that effectively renders it invisible.  Tracking these genetic changes, therefore, allows scientists to group individual HIV infections into distinct clusters that all started at the same time and place.  In Dugas’ case, not only was his virus found to be distantly related to the other eight that were studied, but also the dramatic differences between all nine viruses call the concept of a singular “patient zero” into serious doubt.  HIV killed Dugas in 1984, and it vindicated him 32 years later.

Acknowledgments: Many thanks to Maddy Jennewein, a graduate student in the Virology Ph.D. Program at Harvard University, for providing her expertise and commentary on the topic.

Managing Correspondent: Christopher Gerry

Original Research: 1970s and ‘Patient 0’ HIV-1 genomes illuminate early HIV/AIDS history in North America – Nature

Media Coverage: Researchers Clear ‘Patient Zero’ From AIDS Origin Story – NPR News; HIV Patient Zero cleared by science – BBC News