This study investigates the seasonal relationship between drug-resistant bacteria (E. coli and methicillin-resistant Staphylococcus aureus or MRSA) and antibiotic prescription levels in the United States from 1999–2007.
Retail sales data for five antibiotic classes were gathered from a database that covers more than 70 percent of all U.S. prescriptions. Data was also collected on resistance from an electronic database of susceptibility test results. A time series analysis was performed to measure seasonal patterns of antibiotic resistance.
- Both prescription rates and resistance time series displayed a peak during the winter months, and further analysis revealed that only those prescriptions dispensed in mass quantities displayed any short-term changes in resistance patterns.
- This finding suggests that the amount of antibiotic usage overall is a key factor in shaping the underlying resistance dynamics.
- Reduction of unnecessary antibiotic use in hospitals to offset the resistance rates will likely be ineffective unless unnecessary antibiotic use at the community level is also reduced.
This study does not account for the actual measure of antibiotic consumption, demographic variations, or antibiotic usage in hospitals. Further research could help confirm if these relationships are the same among other resistant bacteria and antibiotics.