The human immunodeficiency virus (HIV-1) ‘jumped’ from the Caribbean to New York City around 1970, triggering the subsequent North American epidemic, reports a paper published online this week in Nature. The study, which incorporates historical and genomic analyses, also clears the name of the man erroneously dubbed ‘Patient Zero’.
When the strain of HIV that infects men who have sex with men - HIV-1 group M subtype B - emerged in North America, it marked a turning point in the HIV/AIDS pandemic, but the details surrounding this transition are unclear. Michael Worobey and colleagues sequenced eight full-length genomes from serum samples originally collected in the USA dating from the 1970s, and show that the virus was already genetically diverse during this time and that it probably emerged from a pre-existing Caribbean epidemic.
They also recovered the HIV-1 genome of an individual known as ‘Patient Zero’. Patient Zero was identified by name in Randy Shilts’ book And the Band Played On. Media coverage of the book insinuated that this man was the ‘source’ of the North American epidemic. However, the genomic analysis performed by Worobey and colleagues indicates that the HIV-1 genome from this individual appeared typical of US strains of the time and was not basal to the US diversity. The authors also reveal that this man was dubbed Patient ‘O’ because he came from ‘Out(side)-of-California’, but the letter ‘O’ later became misinterpreted as the number ‘0’. This typographical error entered the scientific literature and, as a result, the story is still widely believed. However, the authors find no evidence that Patient 0 was the first person infected by this lineage of HIV-1.
The study highlights the importance of using complete viral genomes from early archival specimens, carefully contextualized through historical analysis, without which this detailed picture of the early landmarks in the HIV/AIDS pandemic would not have been possible.