Outbreaks attributed to fresh leafy vegetables, United States, 1973-2012.

Leafy vegetables are an essential component of a healthy diet; however, they have been associated with high-profile outbreaks causing severe illnesses. We reviewed leafy vegetable-associated outbreaks reported to the Centers for Disease Control and Prevention between 1973 and 2012. During the study period, 606 leafy vegetable-associated outbreaks, with 20 003 associated illnesses, 1030 hospitalizations, and 19 deaths were reported. On average, leafy vegetable-associated outbreaks were larger than those attributed to other food types. The pathogens that most often caused leafy vegetable-associated outbreaks were norovirus (55% of outbreaks with confirmed aetiology), Shiga toxin-producing Escherichia coli (STEC) (18%), and Salmonella (11%). Most outbreaks were attributed to food prepared in a restaurant or catering facility (85%). An ill food worker was implicated as the source of contamination in 31% of outbreaks. Efforts by local, state, and federal agencies to control leafy vegetable contamination and outbreaks should span from the point of harvest to the point of preparation.

Physical activity and sitting time in bariatric surgery patients 1-16 years post-surgery.

Physical activity (PA) is an important adjunct to bariatric surgery in the treatment of severe obesity; however, patient PA levels prior to and in the short-term following surgery are usually low. Scarce data exist describing PA and sedentary behaviours in the long term following surgery. The objectives were to describe PA and sitting time in bariatric patients 1-16 years post-surgery and assess their associations with patient, surgery and weight-loss characteristics. A total of 398 bariatric patients (73% female; mean age 47 ± 11 years, mean 6 ± 4 years since surgery) completed a telephone questionnaire. Patients reported moderate-to-vigorous PA (MVPA: # sessions week(-1) ≥30 min), sitting time (h d(-1)) and change in PA and sitting time vs. pre-surgery (more/same/less). Associations with patient, surgery and weight-loss characteristics were assessed. Only 53% of patients reported ≥1 session week(-1) MVPA, mean sitting time was 7 ± 4 h d(-1), 74% of patients reported more PA and 53% reported less sitting, now vs. pre-surgery. Age, sex, smoking status, pre-surgery body mass index, time-since-surgery and percent excess weight lost were significantly associated with PA and/or sitting outcomes. Patients currently experiencing ≥50% excess weight loss had over three times the odds of reporting ≥1 session week(-1) MVPA (odds ratio [95% confidence interval] 3.28 [1.57, 6.89]) and almost four times greater odds of reporting 'more' PA vs. pre-surgery (3.78 [2.15, 6.62]) compared with their less successful counterparts. Results point to low PA and high sedentariness among bariatric patients in the long-term following surgery, associated with several characteristics. Associations with long-term weight management highlight the need for tailored interventions to promote active living in this patient population.

Common source outbreaks of Campylobacter infection in the USA, 1997-2008.

Campylobacter is a common but decreasing cause of foodborne infections in the USA. Outbreaks are uncommon and have historically differed from sporadic cases in seasonality and contamination source. We reviewed reported outbreaks of campylobacteriosis. From 1997 to 2008, 262 outbreaks were reported, with 9135 illnesses, 159 hospitalizations, and three deaths. The annual mean was 16 outbreaks for 1997-2002, and 28 outbreaks for 2003-2008. Almost half occurred in warmer months. Foodborne transmission was reported in 225 (86%) outbreaks, water in 24 (9%), and animal contact in seven (3%). Dairy products were implicated in 65 (29%) foodborne outbreaks, poultry in 25 (11%), and produce in 12 (5%). Reported outbreaks increased during a period of declining overall incidence, and seasonality of outbreaks resembled that of sporadic infections. Unlike sporadic illnesses, which are primarily attributed to poultry, dairy products are the most common vehicle identified for outbreaks.

Assessment of a response bias for aggression over functionally equivalent appropriate behavior.

We evaluated the effects of a dense (fixed-ratio 1) schedule of reinforcement for an 11-year-old boy's mands for toys while aggression produced the same toys on various schedules chosen on the basis of a progressive-ratio probe. Based on the probe session data, we accurately predicted that aggression would be more probable than mands when the schedules were equal or slightly discrepant, but that mands would be more probable when the schedule discrepancy was large.