Every year, there are about 500,000 cases of shigellosis in the United States 1. Shigellosis does not have a marked seasonality, likely reflecting the importance of person-to-person transmission. For more information, see the FoodNet 2011 Surveillance Report.[PDF - 53 pages]
In 2013, the average annual incidence of shigellosis in the United States was 4.82 cases per 100,000 individuals 2.
Shigella infections have not declined appreciably over the past 10 years. The incidence rate of infection with Shigella sonnei decreased from 2008 through 2011, but increased in 2012 3,4.
Resistance to traditional first-line drugs such as ampicillin and trimethoprim-sulfamethoxazole is common. Healthcare providers now rely on alternative drugs like ciprofloxacin and azithromycin to treat infections. However, strains of Shigella resistant to these antibiotics are becoming more common in the United States. Infections caused by antibiotic-resistant Shigella strains can last longer than infections caused by antibiotic-susceptible bacteria (bacteria that can be treated effectively with antibiotics) 5. Because initial treatment can fail, costs are expected to be higher for resistant infections 5. For more information, see Antibiotic / Antimicrobial Resistance.