H. pylori antibiotic resistance
Resistance of H. pylori to antibiotics has reached alarming levels worldwide, although there are regional differences to resistance rates. In the 1990's, the standard treatment of a triple therapy regimen of 7-10 days of twice-daily clarithromycin, metronidazole/amoxicillin, and a proton pump inhibitor eradicated the infection 90% of the time. Success with this has rapidly declined due to increasing resistance to clarithromycin and it's alternative levofloxacin.