Gaetan Dugas was not HIV “patient zero,” responsible for spreading the virus to North America according to a new study published in the scientific journal, Nature, which used a form of genome tracking to trace the virus’ entry into the continent back to the early 1970s in New York City, well before Dugas’ infection.
Dugas, who died from AIDS-related kidney failure in 1984, was exonerated almost a decade ago, though the myth of ‘Patient Zero’ endures as scientists are increasingly able to trace different strains of the virus, hoping to eventually be able to track exactly who gave the virus to whom.
“It may help us to identify communities or networks to focus on in terms of prevention measures,” says Dr Mark Gilbert, clinical associate professor in the population and public health department at the University of British Columbia and lead author of a recent journal article in The Lancet raising concerns about the technology.
“There’s a lot that’s promising, but every tool has another side and so it’s important just as well to be thinking carefully about the future in terms of how these new technologies are being used.”
Although it is not there yet, Gilbert says the emerging technology’s ability to identify individual transmission events may not be far off.
In countries like Canada, where people living with HIV can face the very serious charge of aggravated sexual assault for not disclosing their HIV status, it raises the possibility that the information could aid in further criminalizing and stigmatizing those living with the virus.
Gilbert co-wrote the article with a group of researchers and epidemiologists in response to another study carried out at the BC Centre for Excellence in HIV/AIDS at St Paul’s Hospital in Vancouver. Gilbert and his colleagues are calling for greater transparency and discussion with this growing technology, where the potential benefits and harms are only just coming into view.
“Particularly when it comes to HIV, knowing things around social stigma, sanctions — potentially legal with HIV — you have an extra due diligence to make sure that we’ve thought this through carefully,” Gilbert says, noting the privacy of the patient is paramount.
The Centre for Excellence paper outlined the implementation of an HIV monitoring scheme, where a computer model monitored transmission hotspots by tracking the genotypes of different strains in the community. The model mapped the transmissions, then used the information to notify public health officials about a drug-resistant strain that was growing.
Officials then used the information to prioritize education and outreach programs to get the newly infected patients into treatment as soon as possible, preventing further spread of a difficult to treat strain of HIV.
Art Poon, the lead author and data scientist for the monitoring study, says Gilbert’s concerns are legitimate because this type of data has been misused previously for prosecution of HIV people in transmission cases, despite the current technology’s inability to prove direct person to person transmission. However, he says, the level of anonymization and encryption in the Centre for Excellence system makes abuse of the data virtually impossible.
Because of the potential for criminal sanctions, Poon says they took extraordinary steps to protect the privacy of the patients whose information sits in the database.
“It’s a moral and ethical imperative because it’s our responsibility, as people working with this data, to provide optimal clinical care for people living with HIV,” he says.
“HIV remains criminalized in Canada and there is still tremendous stigma. We’re trying to develop a public health resource that can benefit people at risk of HIV infection in an environment that makes this difficult to do.”
From a public health perspective, the tool represents a small but very useful intervention to deal with the virus, according to Dr Réka Gustafson, medical officer of health for Vancouver Coastal Health who co-wrote the Centre for Excellence paper.
Prior to the mapping system, public health officials had to rely on patient-provided information to try to track transmission. Now, Gustafson says, the technology can help track particular strains as they move through different demographic groups, such as men who have sex with men, intravenous drug users, and people coming from countries where the virus is endemic.
This allows health officials to tailor their interventions to those groups with great precision, she says.
“Let’s say we have identified a group of people at higher risk,” Gustafson says. “Would we ever have the potential to offer them PrEP, for example? Would that be a more effective intervention? It’s a small addition for us to focus our interventions on people who are most likely to benefit from them.”
But as with any other measure, Gustafson says, it must be carefully implemented and evaluated. Early treatment and support of people living with HIV remain the most important public health tools for preventing the spread of HIV, she emphasizes.
Vancouver public health officials and researchers at the Centre for Excellence have invited Gilbert and another author to meet with them monthly to go over the latest reports from the model.
While a “Patient Zero” situation may be unlikely in BC today because of the privacy safeguards put in place, Gilbert says, the underlying concerns remain.
“For me, Gaetan Dugas is an example of the societal stigma around HIV. This is how these stories get created and crafted around HIV to reflect the societal stigma,” Gilbert says.
“So, certainly that’s first and foremost in the minds of myself and other researchers involved in the field of HIV, and always trying to be sensitive around that and minimize the chances of that occurring. But unfortunately it is a reflection of the underlying stigma that exists.”