Published January, 2020

HIV transmission networks among transgender women in Los Angeles County, CA, USA: a phylogenetic analysis of surveillance data, Manon Ragonnet-Cronin, et al., The Lancet (2019)


Using data collected by the Los Angeles County Department of Public Health, this study used new techniques to analyze molecular data to map HIV transmission networks. More notable than the study’s conclusions—identifying transgender women as comparatively “high risk” for HIV transmission—was its controversial use of molecular data, which many advocates for people living the HIV believe risks infringing on their civil rights and increasing criminal surveillance of communities affected by HIV.

The study—which was funded by the National Institutes of Health and the California HIV and AIDS Research Network—analyzed more than 22,000 data points collected in Los Angeles since 2006 to model transmission networks in Los Angeles. Each data point was categorized by sex and sexual orientation using information collected by health care providers and public health officials. The researchers then used molecular data, including the “genetic distance” between samples, to model transmission networks. The authors reported findings included that transgender women were more likely to be linked in to other transgender women and to men who do not identify as men who have sex with men. The study’s authors concluded that such data analysis could give direction to future public health efforts.

While the study’s authors trumpeted the potential public health benefits of molecular data analysis, the study did not address the concerns of many advocates that molecular data analysis could be used without patients’ consent to target certain communities or even individuals for increased criminal justice surveillance. Notably, the study did not state whether the molecular data samples were incorporated into the data set with the knowledge and consent of the persons from whom they were taken. Nor did it address how that data was stored and shared with researchers.