University of Wisconsin–Madison researchers have recently revealed that the effectiveness of common antibiotics could depend on the neighborhood where you live. Here are the details.

An innovative look at an old problem: Led by postdoctoral fellow Laurel Legenza, researchers at UW–Madison’s School of Pharmacy and State Cartographer’s Office worked with colleagues from three Wisconsin health systems to combine antibiotic resistance data from different locations throughout the state to gauge the effectiveness of a pair of common antibiotic treatments for Escherichia coli infections.

The combination of data allowed the team to identify neighborhood-level patterns in how well the antibiotics treated E. coli. They found meaningful differences between census block groups in the pathogen’s susceptibility to the two antibiotic treatments. Census block groups are a smaller unit within census tracts, each home to around 600 to 3,000 people.

The study, recently published in the journal Scientific Reports, is an innovative approach to the longstanding health care practice of tracking antibiotic resistance.

“Antibiotic resistance stats are not new, but usually they’re done at a health system level,” says Legenza. “Some large health systems may track resistance at the ICU level and compare it to the general hospital, but the data is not well understood at a community level. We took all that data and looked at where these patients live.”

What’s the big deal? Mapping variations in antibiotic resistance could help patients receive better informed treatment decisions from their health care providers, Legenza says. For instance, resistance maps could reveal neighborhoods where E. coli infections are easily treated with antibiotics with fewer side effects.

The study offers a proof-of-concept that such granular resistance mapping is possible. The research team is already planning more mapping studies and investigations into socio-economic and environmental factors that may play a role in variations.