Cases of Infection, Incidence, and Trends
In 2013, FoodNet identified 19,056 cases of infection, 4,200 hospitalizations, and 80 deaths (Table). The number and incidence per 100,000 population were Salmonella (7,277 [15.19]), Campylobacter (6,621 [13.82]), Shigella (2,309 [4.82]), Cryptosporidium (1,186 [2.48]), STEC non-O157 (561 [1.17]), STEC O157 (552 [1.15]), Vibrio (242 [0.51]), Yersinia (171 [0.36]), Listeria (123 [0.26]), and Cyclospora (14 [0.03]). Incidence was highest among persons aged ≥65 years for Cyclospora, Listeria, and Vibrio and among children aged <5 years for all the other pathogens.
Among 6,520 (90%) serotyped Salmonella isolates, the top serotypes were Enteritidis, 1,237 (19%); Typhimurium, 917 (14%); and Newport, 674 (10%). Among 231 (95%) speciated Vibrio isolates, 144 (62%) were V. parahaemolyticus, 27 (12%) were V. alginolyticus, and 21 (9%) were V. vulnificus. Among 458 (82%) serogrouped STEC non-O157 isolates, the top serogroups were O26 (34%), O103 (25%), and O111 (14%).
Compared with 2010–2012, the 2013 incidence was significantly lower for Salmonella (9% decrease; CI = 3%–15%), higher for Vibrio (32% increase; CI = 8%–61%) and not significantly changed for other pathogens (Figure 1). Compared with 2006–2008, the 2013 incidence was significantly higher for Campylobacter and Vibrio (Figure 2). The overall incidence of infection with six key foodborne pathogens was not significantly different in 2013 compared with 2010–2012 or 2006–2008.
Figure 1.
Estimated percentage change in incidence of culture-confirmed bacterial and laboratory-confirmed parasitic infections in 2013 compared with average annual incidence during 2010–2012, by pathogen — Foodborne Diseases Active Surveillance Network, United States
Abbreviations: CI = confidence interval; STEC = Shiga toxin–producing Escherichia coli.
* No significant change = 95% CI is both above and below the no change line; significant increase = estimate and entire CI are above the no change line; significant decrease = estimate and entire CI are below the no change line.
Figure 2.
Relative rates of culture-confirmed infections with Campylobacter, STEC* O157, Listeria, Salmonella, and Vibrio compared with 2006–2008 rates, by year — Foodborne Diseases Active Surveillance Network, United States, 2006–2013 †
* Shiga toxin–producing Escherichia coli.
†The position of each line indicates the relative change in the incidence of that pathogen compared with 2006–2008. The actual incidences of these infections cannot be determined from this figure.
Compared with 2010–2012, the 2013 incidence of infection with specific Salmonella serotypes was significantly lower for Enteritidis (14% decrease; CI = 0.2%–25%) and Newport (32% decrease; CI = 17%–44%) and not significantly changed for Typhimurium. Compared with 2006–2008, however, the 2013 incidence of infection was significantly changed only for Typhimurium (20% decrease; CI = 10%–28%).
Among 62 cases of postdiarrheal HUS in children aged <18 years (0.56 cases per 100,000) in 2012, 38 (61%) occurred in children aged <5 years (1.27 cases per 100,000). Compared with 2006–2008, the incidence was significantly lower for children aged <5 years (36% decrease; CI = 9%–55%) and for children aged <18 years (31% decrease; CI = 7%–49%).
In addition to culture-confirmed infections (some with a positive CIDT result), there were 1,487 reports of positive CIDTs that were not confirmed by culture, either because the specimen was not cultured at either the clinical or public health laboratory or because a culture did not yield the pathogen. For 1,017 Campylobacter reports in this category, 430 (42%) had no culture, and 587 (58%) were culture-negative. For 247 STEC reports, 59 (24%) had no culture, and 188 (76%) were culture-negative. The Shiga toxin–positive result was confirmed for 65 (34%) of 192 broths sent to a public health laboratory. The other reports of positive CIDT tests not confirmed by culture were of Shigella (147), Salmonella (69), Vibrio (four), Listeria (two), and Yersinia (one).
Morbidity and Mortality Weekly Report. 2014;63(15):328-332. © 2014 Centers for Disease Control and Prevention (CDC)
