Outbreaks attributed to pork in the United States, 1998-2015.

Each year in the United States, an estimated 525 000 infections, 2900 hospitalizations, and 82 deaths are attributed to consumption of pork. We analyzed the epidemiology of outbreaks attributed to pork in the United States reported to the Centers for Disease Control and Prevention (CDC) 1998-2015. During that period, 288 outbreaks were attributed to pork, resulting in 6372 illnesses, 443 hospitalizations, and four deaths. The frequency of outbreaks attributed to pork decreased by 37% during this period, consistent with a decline in total foodborne outbreaks. However, outbreaks attributed to pork increased by 73% in 2015 (19 outbreaks) compared with the previous 3 years (average of 11 outbreaks per year), without a similar increase in total foodborne outbreaks. Most (>99%) of these outbreaks occurred among people exposed in the same state. The most frequent etiology shifted from Staphylococcus aureus toxin during 1998-2001 (19%) to Salmonella during 2012-2015 (46%). Outbreaks associated with ham decreased from eight outbreaks per year during 1998-2001, to one per year during 2012-2015 (P < 0·01). Additional efforts are necessary to reduce outbreaks and sporadic illnesses associated with pork products.

Multiple-aetiology enteric infections involving non-O157 Shiga toxin-producing Escherichia coli--FoodNet, 2001-2010.

We describe multiple-aetiology infections involving non-O157 Shiga toxin-producing Escherichia coli (STEC) identified through laboratory-based surveillance in nine FoodNet sites from 2001 to 2010. A multiple-aetiology infection (MEI) was defined as isolation of non-O157 STEC and laboratory evidence of any of the other nine pathogens under surveillance or isolation of >1 non-O157 STEC serogroup from the same person within a 7-day period. We compared exposures of patients with MEI during 2001-2010 with those of patients with single-aetiology non-O157 STEC infections (SEI) during 2008-2009 and with those of the FoodNet population from a survey conducted during 2006-2007. In total, 1870 non-O157 STEC infections were reported; 68 (3.6%) were MEI; 60 included pathogens other than non-O157 STEC; and eight involved >1 serogroup of non-O157 STEC. Of the 68 MEI, 21 (31%) were part of six outbreaks. STEC O111 was isolated in 44% of all MEI. Of patients with MEI, 50% had contact with farm animals compared with 29% (P < 0.01) of persons with SEI; this difference was driven by infections involving STEC O111. More patients with non-outbreak-associated MEI reported drinking well water (62%) than respondents in a population survey (19%) (P < 0.01). Drinking well water and having contact with animals may be important exposures for MEI, especially those involving STEC O111.

Outbreaks of non-O157 Shiga toxin-producing Escherichia coli infection: USA.

Non-O157 Shiga toxin-producing Escherichia coli (STEC) infections are increasingly detected, but sources are not well established. We summarize outbreaks to 2010 in the USA. Single-aetiology outbreaks were defined as ⩾2 epidemiologically linked culture-confirmed non-O157 STEC infections; multiple-aetiology outbreaks also had laboratory evidence of ⩾2 infections caused by another enteric pathogen. Twenty-six states reported 46 outbreaks with 1727 illnesses and 144 hospitalizations. Of 38 single-aetiology outbreaks, 66% were caused by STEC O111 (n = 14) or O26 (n = 11), and 84% were transmitted through food (n = 17) or person-to-person spread (n = 15); food vehicles included dairy products, produce, and meats; childcare centres were the most common setting for person-to-person spread. Of single-aetiology outbreaks, a greater percentage of persons infected by Shiga toxin 2-positive strains had haemolytic uraemic syndrome compared with persons infected by Shiga toxin 1-only positive strains (7% vs. 0·8%). Compared with single-aetiology outbreaks, multiple-aetiology outbreaks were more frequently transmitted through water or animal contact.