Cases of Infection, Incidence, and Trends
During 2018, FoodNet identified 25,606 cases of infection, 5,893 hospitalizations, and 120 deaths. The incidence of infection (per 100,000 population) was highest for Campylobacter (19.5) and Salmonella (18.3), followed by STEC (5.9), Shigella (4.9), Vibrio (1.1), Yersinia (0.9), Cyclospora (0.7), and Listeria (0.3) (Table). Compared with 2015–2017, the incidence significantly increased for Cyclospora (399%), Vibrio (109%), Yersinia (58%), STEC (26%), Campylobacter (12%), and Salmonella (9%). The number of bacterial infections diagnosed by CIDT (with or without reflex culture§) increased 65% in 2018 compared with the average annual number diagnosed during 2015–2017; the increase ranged from 29% for STEC to 311% for Vibrio (Figure 1). In 2018, the percentage of infections diagnosed by DNA-based syndrome panels was highest for Yersinia (68%) and Cyclospora (67%), followed by STEC (55%), Vibrio (53%), Shigella (48%), Campylobacter (43%), Salmonella (33%), and was lowest for Listeria (2%). In 2018, a reflex culture was attempted on 75% of specimens with positive CIDT results, ranging from 64% for Campylobacter to 100% for Listeria (Figure 1). The percentage of specimens with a reflex culture in 2018 was 14% higher than that during 2015–2017, ranging from a 7% decrease for STEC to a 55% increase for Shigella (Figure 2). Among specimens with reflex culture in 2018, the percentage that yielded the pathogen was highest for Listeria (100%) and Salmonella (86%), followed by STEC (64%), Campylobacter (59%), Shigella (56%), Yersinia (50%), and Vibrio (37%) (Figure 1) (Figure 2).
Figure 1.
Number of infections diagnosed by culture or culture-independent diagnostic tests (CIDTs), by pathogen, year, and culture status — CDC's Foodborne Diseases Active Surveillance Network,* 2015–2018†
Abbreviation: STEC = Shiga toxin–producing Escherichia coli.
*Connecticut, Georgia, Maryland, Minnesota, New Mexico, Oregon, Tennessee, and selected counties in California, Colorado, and New York.
†Data for 2018 are preliminary.
Figure 2.
Percentage of infections diagnosed by culture-independent diagnostic tests (CIDTs), positive CIDTs with a reflex culture,* and reflex cultures that yielded the pathogen, by pathogen — CDC's Foodborne Diseases Active Surveillance Network,† 2015–2017 and 2018§
Abbreviation: STEC = Shiga toxin–producing Escherichia coli.
*Culture of a specimen with a positive CIDT result.
†Connecticut, Georgia, Maryland, Minnesota, New Mexico, Oregon, Tennessee, and selected counties in California, Colorado, and New York.
§Data for 2018 are preliminary.
Among 7,013 (87%) serotyped Salmonella isolates, the three most common were Enteritidis (2.6 per 100,000 population), Newport (1.6), and Typhimurium (1.5), similar to those during 2015–2017. Among 1,570 STEC isolates tested, 440 (28%) were determined to be O157. Among 662 non-O157 STEC isolates serogrouped, the most common were O103 (31%), O26 (28%), and O111 (24%). The incidence compared with 2015–2017 remained unchanged for both O157 and non-O157 STEC.
FoodNet identified 54 cases of postdiarrheal hemolytic uremic syndrome in children (0.49 cases per 100,000) during 2017; 36 (67%) occurred among children aged <5 years (1.22 cases per 100,000). Incidence was not significantly different compared with that during 2014–2016.
Morbidity and Mortality Weekly Report. 2019;68(16):369-373. © 2019 Centers for Disease Control and Prevention (CDC)
