Mapping Antibiotic Use and Resistance

New data reveals troubling trends in the pharmaceutical fight against bacteria.

Nov 17, 2011
Bob Grant


Though rates of antibiotic use across the United States have been decreasing, people in Southeast regions of the country take about twice as many antibiotics as residents of the Northwest, according to a new analysis that tracked use of the drugs from 1999 to 2007. West Virginia, Kentucky, Tennessee, Louisiana, and Alabama were the five states with the highest antibiotic use, while Alaska, Oregon, California, and Washington had the lowest use rates. As a whole, the United States had a lower combined resistance score—meaning antibiotic-resistant pathogens are less of a problem—than some countries in Eastern and Southern Europe, but had a higher score than many Nordic countries and European powers, such as the UK and Germany.

While overall antibiotic use in the United States dropped by 12 percent during the study period, according to the report published yesterday on the website of the Center for Disease Dynamics, Economics & Policy (CDDEP), prescribing rates for a powerful class of antibiotics known as fluoroquinolones increased by 49 percent. The alarming thing from an epidemiological standpoint is that fluoroquinolones are now seven times less likely to work against Escherichia coli than they were in 1999. Meanwhile, the market share of penicillins, which have long been the most popular of antibiotics, has declined by 28 percent, with doctors instead prescribing increasingly powerful antibiotics.

In conjunction with releasing this resistance data, Extending the Cure, a project of the CDDEP, also published a paper this week detailing a new method for tracking trends in antibiotic resistance. Appearing in BMJ Open, the study describes how the Drug Resistance Index (DRI) operates something like a Consumer Price Index for antibiotic resistance, aggregating information about trends in E. coli and Acinetobacter baumannii resistance and antibiotic use into a single measure of antibiotic resistance over time. The researchers calculated that DRI in the United States for E. coli rose from 0.25 to 0.30 from 1999 to 2006, and the DRI for Acinetobacter spp. increased from 0.41 to 0.48 over that same time period.

“Mapping the geography of antibiotic use and summarizing their effectiveness with a Drug Resistance Index bring us one step closer to the solutions we urgently need in order to curtail this public health crisis,” said Ramanan Laxminarayan, director of Extending the Cure and author on the BMJ Open paper. “If we do nothing, resistance will continue to develop and our most valuable antibiotics ultimately will fail.”