Contaminated ventilator air flow sensor linked to Bacillus cereus colonization of newborns.

We investigated Bacillus cereus-positive tracheal aspirates from infants on ventilators in a neonatal intensive care unit. Multilocus sequence typing determined a genetic match between strains isolated from samples from a case-patient and from the air flow sensor in the ventilator. Changing the sterilization method for sensors to steam autoclaving stopped transmission.

Outbreak of Shiga toxin-producing Escherichia coli (STEC) O157:H7 associated with romaine lettuce consumption, 2011.

BACKGROUND: Shiga toxin-producing Escherichia coli (STEC) O157:H7 is the causal agent for more than 96,000 cases of diarrheal illness and 3,200 infection-attributable hospitalizations annually in the United States. MATERIALS AND METHODS: We defined a confirmed case as a compatible illness in a person with the outbreak strain during 10/07/2011-11/30/2011. Investigation included hypothesis generation, a case-control study utilizing geographically-matched controls, and a case series investigation. Environmental inspections and tracebacks were conducted. RESULTS: We identified 58 cases in 10 states; 67% were hospitalized and 6.4% developed hemolytic uremic syndrome. Any romaine consumption was significantly associated with illness (matched Odds Ratio (mOR) = 10.0, 95% Confidence Interval (CI) = 2.1-97.0). Grocery Store Chain A salad bar was significantly associated with illness (mOR = 18.9, 95% CI = 4.5-176.8). Two separate traceback investigations for romaine lettuce converged on Farm A. Case series results indicate that cases (64.9%) were more likely than the FoodNet population (47%) to eat romaine lettuce (p-value = 0.013); 61.3% of cases reported consuming romaine lettuce from the Grocery Store Chain A salad bar. CONCLUSIONS: This multistate outbreak of STEC O157:H7 infections was associated with consumption of romaine lettuce. Traceback analysis determined that a single common lot of romaine lettuce harvested from Farm A was used to supply Grocery Store Chain A and a university campus linked to a case with the outbreak strain. An investigation at Farm A did not identify the source of contamination. Improved ability to trace produce from the growing fields to the point of consumption will allow more timely prevention and control measures to be implemented.

Convalescent cultures for control of shigellosis outbreaks.

BACKGROUND: A shigellosis outbreak in the St Louis, Missouri metropolitan area. OBJECTIVE: To evaluate the utility of a second convalescent stool culture following an initial negative convalescent stool culture among persons excluded from work or childcare for shigellosis. METHODS: An observational study of 219 shigellosis cases. Laboratory-confirmed shigellosis patients who are required to submit 2 negative convalescent stool cultures before returning to childcare facilities or work and who submitted at least 1 culture were included in the study. Univariate and multivariable logistic regression analyses were performed to evaluate potential risk factors for a convalescent stool culture being positive. RESULTS: Of 308 persons, 219 (71%) submitted at least 1 convalescent stool culture, and 164 (53%) submitted 2 negative convalescent stool cultures. Among 172 cases with > or =2 follow-up cultures, the probability that the second test result would agree with the first test result was 7% for a "positive" initial stool culture, and 100% for a "negative" stool culture. When adjusted for age, sex, and child care attendance, treated case-patients who had Shigella organisms in the first convalescent culture were more likely to have had stool collected <48 hours after the treatment completion and were more likely to have been treated with trimethoprim-sulfamethoxazole. CONCLUSIONS: Compliance is poor with statutes requiring serial negative stool cultures among certain populations with shigellosis. Absence of Shigella species in the first convalescent stool culture of patients recovering from shigellosis appears to be an adequate measure of bacteriologic cure; however, the health impacts of requiring any convalescent cultures during shigellosis outbreaks remain unclear.

Outbreak of echovirus 18 meningitis in a rural Missouri community.

This is a case-control study of viral meningitis outbreak in Perry County, Missouri. All case-patients had viral meningitis per routine CSF analysis or PCR testing. Enterovirus VP1-specific RT-PCR and sequencing was performed on CSF. Univariate and multivariable logistic regression analysis was done to evaluate risk factors. The meningitis attack rate was 1/1,000 population. The main risk factor for meningitis was association with childcare. In patients with signs of meningitis, but normal routine CSF analysis, molecular testing of the CSF is helpful for conclusive diagnosis.

Outbreak of rash in children associated with recreational mud exposure.

We conducted an investigation of a rash outbreak in children who attended the "Mud Mania Festival." The mean incubation period of illness was 26 hours, and mean duration was 4.3 days. Time spent in mud was associated with the extent of rash in a dose-response fashion. The cultures from lesions of two unrelated cases yielded Enterobacter cloacae.