A new study published in The Lancet uses molecular surveillance methods to help understand HIV transmission among transgender women in Los Angeles County. While the researchers believe the study is proof that molecular surveillance can help public health entities better target prevention efforts, activists are concerned about the ways in which these methods could be used in states where HIV transmission remains criminalized.
Studies like this rely on data collected for genotypic HIV drug resistance testing. Such testing is a routine part of care, when a patient is newly diagnosed or starting or switching antiretroviral treatments, to help health care providers choose the best regimen. The data are stored by state and local health departments and then reported to the Centers for Disease Control and Prevention (CDC) through the National HIV Surveillance System (NHSS). Though the CDC argues that these data are used to examine the genetics of the virus and not to track individuals, activists point out that patients are never asked for consent to be part of this surveillance system and that the data are not stored anonymously. As the ability to analyze these data improves, so do the possibilities of using it to prove who gave HIV to whom.
Not surprisingly, activists and public health researchers are divided on whether molecular surveillance studies are the best way to take prevention efforts into the future.
The Current Study
The Los Angeles County Department of Health has been collecting molecular HIV data since 2006 that are linked to demographic data including race, gender, and HIV transmission risk factors. For the current study, researchers from the University of California, San Diego and Imperial College London used the data to reconstruct transmission networks based on the rate of genetic mutations in the virus. They then looked specifically at the transgender women in these networks to see how they were connected to other population groups at risk for HIV transmission.
The analysis found that transgender women were more likely than expected to be in similar transmission networks with heterosexual cisgender men, and less likely than expected to be connected to men who have sex with men (MSM). Manon Ragonnet-Cronin, Ph.D., lead author of the study, cautions against misunderstanding this conclusion. Transgender women were still most often linked in transmission networks to MSM, but the findings of how often they were linked to other transgender women and to cisgender men who did not identify as MSM were nonetheless surprising.
Ragonnet-Cronin and her co-authors think that these results are useful. They write: "[The results show] the potential to use molecular epidemiology both to identify clusters that are likely to include undiagnosed transgender women with HIV and to improve the targeting of public health prevention and treatment services to transgender women." Ragonnet-Cronin cited partner interviews as an example of an intervention that could be used based on the genetic network. Because of limited resources, not everyone in Los Angeles County gets these interviews, in which they are asked to help the department find others who might have been exposed in the same way they were. Cluster data could allow health departments to prioritize individuals to interview by helping them understand which sexual networks are most likely to include undiagnosed transgender women. These women could then be targeted for testing, treatment, or pre-exposure prophylaxis (PrEP).
She added that in other contexts, such as in countries that have met UNAIDS' 90-90-90 goals, this can help public health experts understand in fine detail where new infections are coming from.
The CDC agrees that these types of analyses have great potential. In information culled from its website and sent in response to a request for information, the agency said: "We want to use all of the tools in our toolbox to get us closer to the goal of no new infections. Analysis of molecular data can help get us there by identifying areas with substantially higher rates of transmission, where resources for testing, linkage to care, and prevention are needed most."
HIV activists, however, are skeptical about these data and think that using them this way has potential to do grave harm. Naina Khanna, executive director with Positive Women's Network, said that the most basic issue is that people's data are being collected and stored without their consent: "… many of us are fundamentally uncomfortable that this type of critical information is being tracked and stored."
She pointed out that there are still two dozen U.S. states and territories that criminalize various types of alleged HIV exposure, non-disclosure, and transmission. "People living with HIV are being prosecuted and criminalized anyway based on somebody's word against them, so this technology is being spread and funded in ways that are new and may create more vulnerability." The analyses that are currently being conducted do not draw any conclusions about the directionality of infection -- they cannot demonstrate whether or not one person contracted HIV from another person -- but Khanna thinks that this distinction will likely be lost on prosecutors, judges, and jurors. And some people suspect that the ability to determine directionality is soon coming.
She added that there are no assurances from the CDC that the data they are collecting are not being shared with Immigration and Customs Enforcement (ICE) or law enforcement. In this political environment, she said, it would be foolish to assume such data would not be used to target immigrants or other vulnerable populations.
The CDC said in its statement that all HIV data are encrypted and sent to the agency without names and that it requires state and city health departments to comply with strict standards for data security as a condition of funding. That said, at the state and local level, the data are identifiable.
Ragonnet-Cronin pointed out that the data are collected not for analyses like these, but to help health care providers track drug resistance and ensure that drug regimens continue to work for individuals and communities, and that this is an important goal in and of itself. Still, she acknowledges that the privacy concerns are valid: "Researchers and public health departments are interested in probabilistic associations with HIV transmission, and not in identifying direct transmission events; nonetheless, we understand the protection that should be applied to this sensitive data. Conversations with patient groups over what they consider to be a favorable risk-benefit ratio are ongoing."
Risk/Benefit of Molecular HIV Surveillance
Ultimately, the risk/benefit analysis is where researchers and activists may part ways. Khanna expressed skepticism over whether this new analysis, for example, provides anything we don't already know or couldn't get from sitting down with a group of transgender women in LA. She worries that these analyses are becoming more common because researchers get excited about fancy new technologies and consistently undervalue old-fashioned social science research, and not because the new technologies add anything of importance.
Ragonnet-Cronin, however, believes that this kind of data can get to information that social science research cannot. For one thing, these analyses don't just look at sexual contacts, they look specifically at sexual contacts that lead to HIV acquisition. Research has shown that -- possibly because most people aren't diagnosed with HIV until about three years or longer after they acquired it -- most people are not very good at guessing from whom they may have contracted the virus. Moreover, it is quicker, easier, and far less expensive to analyze data from thousands of people than to collect it from focus groups, and researchers are able to infer statistically significant results, which they couldn't get from smaller samples.
In 2017, Project Inform, along with Northwestern School of Medicine and the Third Coast Center for AIDS Research held a consultation in Chicago and later published a report from the gathering that in part calls for more transparency from CDC and public health departments with communities most impacted about how the data are collected, stored, secured, and for what purposes they can and cannot be used.
Still, some activists like Khanna do not think this adds enough value to make it worth it: "We know what's needed to address the epidemic in the United States. We have to improve access to health care. We need to get interventions for all people with HIV. If we can suppress community viral loads to the levels where transmission isn't happening -- that's the best use of our resources."