METHODS: Data on laboratory-confirmed Campylobacter infections were summarized from the Nationally Notifiable Disease Surveillance System, Foodborne Diseases Active Surveillance Network, National Outbreak Reporting System, and National Antimicrobial Resistance Monitoring System. Antimicrobial resistance for ciprofloxacin is defined as a minimum inhibitory concentration (MIC) ≥1μg/mL and erythromycin resistance as MIC ≥8 μg/mL for C. jejuni and ≥16 μg/mL for C. coli.
RESULTS: During 2004–2012, 303,518 culture-confirmed Campylobacter infections were reported. The average annual incidence was 11.4 cases/100,000 population, with substantial variation by state (range: 3.2–48.0/100,000). Incidence was over 2-fold greater among patients aged <5 years than in older age groups. Incidence rates (IR) among males were highest in all age groups. Data on race/ethnicity were included in 52–58% of reports; assuming reported data was representative of the population as a whole, American Indians had the highest IRs (14.2/100,000), followed by Whites (12.3/100,000), and Asians (8.5/100,000). Blacks had the lowest IRs in all age groups (4.0/100,000). IRs among Hispanics (12.2/100,000) were higher than non-Hispanics (9.3/100,000). IRs in the western states and rural counties were higher (16.2/100,000 and 14.2/100,000) than in southern states and metropolitan counties (6.7/100,000 and 11.0/100,000). Comparing 2004–2006 with 2010–2012 data, annual incidence increased by 21% from 10.5/100,000 to 12.7/100,000, with the greatest IR increases found in non-Hispanics (44%), persons >60 years of age (40%), Blacks (35%), and southern states (32%). A total of 353 Campylobacter outbreaks were reported; comparing 2004–2009 with 2010–2012, the annual mean increased from 29 to 51, and the number of illnesses per outbreak decreased from 40 to 14. Among 5,863 isolates tested for antibiotic susceptibility, 4,793 (82%) were from domestically acquired infections. Comparing 2004–2010 with 2011–2012, we found that antimicrobial resistance increased—both for ciprofloxacin (domestic: 13.0% versus 17.0%; travel-associated: 60.2% versus 67.5%) and for erythromycin (travel-associated: 3.6% versus 6.8%).
CONCLUSIONS: During 2004–2012, incidence of Campylobacter infection, outbreaks, and antimicrobial resistance patterns increased and showed marked demographic and geographic differences. These findings underscore the importance of national surveillance that includes standardized data collection and the need to clarify risk factors to guide and target control measures.