The Centers for Disease Control and Prevention recently issued a first-of-its-kind analysis showing that 2.1 percent of heterosexuals living in urban areas with high rates of poverty in the U.S. are infected with HIV. The findings indicate a massive health concern for many low-income cities in America, who may now face generalized HIV epidemics as defined by the United National Join Program on HIV/AIDS (UNAIDS).

According to UNAIDS, a generalized epidemic is one that is “firmly established in the general population, with an overall HIV prevalence in the general population of more than 1 percent.” While subpopulations – such as men who have sex with men and intravenous drug users – contribute disproportionately to new HIV infections, heterosexual transmission also sustains the epidemic without inclusion of these groups.

The analysis revealed that poverty is the key demographic factor associated with HIV infection among heterosexual adults living in inner cities. However, the report found no differences in HIV prevalence by race or ethnicity in low-income populations.

“These findings have significant implications for how we think about HIV prevention. We can’t look at HIV in isolation from the environment in which people live,” said Jonathan Mermin, director of the CDC’s Division of HIV/AIDS Prevention, in a statement.  “This analysis points to an urgent need to prioritize HIV prevention efforts in disadvantaged communities.”