Where you live, where you work and even where you socialize plays a huge role in your health.
Straight black women living in Philadelphia, for instance, are at a higher rick of contracting HIV than heterosexual white female Philadelphians.
Brawner believes the reason heterosexual black women suffer so disproportinately is because of something she calls geobehavioral vulnerability.
“Geobehavioral vulnerability to HIV suggests that it is not just what you do, but also where you do it, and with whom, that increases your risk of HIV infection,” Brawner said.
In her 22-month study, Brawner explored racial/ethnic and geographic differences in four Philadelphia census tracts —two predominately black and two predominately white. For each race, one tract had a high-HIV prevalence and low-HIV prevalence.
The study looked at things like access to health care, the number of vacant lots in area neighborhoods and unemployment to see how they played a role on the spike in risk.
"The data generated from this research support a much needed paradigm shift to acknowledge the role negative social and structural factors like limited social cohesion, inadequate health-related resources and poverty have on the HIV/AIDS pandemic," Brawner said of her findings.
The social cohesion finding is key; previous studies have proven that in populations where women outnumber men, men tend to have more heterosexual sexual partners, increasing the likelihood of spreading HIV.
Philadelphia has more black women than black men, partially due to high incarceration and early death figures for its black male population. Exacerbating this, Brawner's study found, is the fact that Philadelphia's black neighborhoods tend to be fairly tight-knit, leading black women to date men from fairly small social circles. One infected man, then, could easily infect multiple black women.
Brawner also found that poorer populations were more at risk for HIV due to the impact of drugs; sharing needles has been proven to aid the spread of HIV.
It is also known that populations that engage in male gay sex suffer greater raters of HIV infection. The study found that transmission from black men who engaged in male-to-male sexual contact to black heterosexual women was limited.
For Philadelphia's black women, the problem of HIV is a very serious one.
The city's Department of Public Heath's data state that the rate of newly diagnosed HIV infections among all black women was 24.9 per 100,000 residents in 2015. Black men had the rate of 103.8 per 100,000 while white men had a rate was 16.5. White women had a rate of 3.8 in 100,000. When looking at men who have sex with men, the infection rate was a startling 906.1 in 100,000.
Brawner hopes that her research can help to reduce these numbers.
And the professor isn't stopping with just research.
She plans to stop the spread of HIV with the help of a new $1 million grant from the Centers for Disease Control, The Inquirer reports.
Brawner has created a program that focuses on teens with mental illness called Project Gold, and works to teach them how to avoid HIV and other STIs. In a city where the HIV infection rate is five times the national average, hers is crucial work.