New study clears “Patient Zero” of responsibility for HIV in US

By Sally Robertson, B.Sc.Oct 28 2016

A new genetic analysis has shown that the French-Canadian flight attendant Gaétan Dugas who was posthumously blamed for spreading HIV across North America, was not the “Patient Zero” of the epidemic.

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Dugas became notorious as the person responsible for the US AIDS crisis after he slept with men in California and New York during the early 1980s.

The evidence from this latest study in fact shows that HIV probably arrived in the U.S around 1971 and that Dugas was simply one of many thousands who had been infected years before the HIV epidemic was even recognized in the 80s.

The research, which was led by Dr Michael Worobey (University of Arizona) compared Dugas's blood sample with samples taken from men in the late 1970s in New York and San Francisco.

Worobey and team managed to isolate HIV in eight of those samples. They then sequenced the HIV genomes and assessed how the virus had mutated over time. The eight samples analysed were then compared to HIV samples from the Caribbean and Africa.

As reported in Nature, the researchers found that the viral genome from Dugas closely resembled later HIV samples and viral genomes from the east coast resembled much more closely the early California virus than they did the viral genome from Dugas. Their molecular clockwork showed that there was striking genetic diversity of the virus in the US by the late 1970s. HIV had already been circulating and mutating in US hosts a decade before Dugas arrived in the country. The results even suggest that the US strain arrived in the Caribbean from Africa in the late 1960s, then arrived in New York by around 1971 and eventually reached San Francisco in the mid-70s.

Beatrice Hahn, HIV expert from the University of Pennsylvania, says the finding:

“puts to rest this silly Patient Zero story. It’s pretty clear that the 1978 and 1979 samples definitely predated the description of the disease in the 1980s and there wasn’t just one person infected at that time — people were infected in NYC and San Francisco.”

The study clears Dugas from having brought the virus into the US and helping it hop from one side of the country to the other.

“While he did link AIDS cases in New York and Los Angeles through sexual contact, our results refute the widespread misinterpretation that he also infected them with HIV-1,” write Worobey and team.

Hahn adds: “The point was those people were already infected and no one knew about it because they weren’t symptomatic and there was no way of finding they had a virus that no one knew existed.”