In November 1993, clusters of gastroenteritis in six states following oyster consumption were investigated to identify common features, and stool samples were obtained to identify a pathogen. Efforts were made to account for all potentially contaminated oysters using harvest tags and the interstate recall system. Consumption of oysters was associated with illness in 10 clusters; no other food was implicated. A Norwalk-like virus was detected by electron microscopy in 9 of 18 samples and by reverse transcription-polymerase chain reaction in 20 of 26 samples from 6 clusters. Nucleotide sequences of a 123-bp fragment from all specimens were identical, consistent with a common source outbreak. Implicated oysters were harvested from the Louisiana coast between 9 and 12 November. Although some were recalled and destroyed, most oysters harvested from the area during this time remain unaccounted for. Current regulations and commercial practices need to be revised to permit thorough tracing and recall of contaminated oysters and to improve control of future epidemics.

Six chronic hemodialysis patients acquired bloodstream infections (BSIs) with Klebsiella pneumoniae of the same serotype and similar plasmid profile during an 11-day period. The 6 case-patients were more likely than noncase-patients to have received dialysis during the fourth shift (p < 0.05) and to have their dialyzers reprocessed for reuse after those of the noncase-patients (p = 0.05). Investigation identified a patient during the same shift with an arteriovenous fistula infected with K pneumoniae. The dialyzer reprocessing technician did not change gloves between contacting patients and their dialyzers in the treatment area and reprocessing the case-patients’ dialyzers at the end of the fourth shift. We conclude that the outbreak of BSIs was caused by cross-contamination of the case-patients’ dialyzers with bacteria from the gloves of the reprocessing technician and by inadequate dialyzer disinfection. After revised dialyzer reprocessing techniques and glove-changing policies were instituted, no further clusters of BSIs occurred.

in the vicinity of Silver Spring, Md. Shrimp salad served in a fast-food restaurant was implicated as the source of infection. Stool cultures were obtained from 104 employees, and serum Vi antibodies were assayed in 97 of the employees. Salmonella typhi was isolated from stool cultures of an 18-year-old asymptomatic female employee, who was a food handler. A high level of Vi antibodies (79.0 Fg/ml), measured by radioimmunoassay, was found in her serum. She had emigrated from an endemic area at the age of 14 years and had visited that endemic area 2 years previously. The causal relation between the carrier and the 10 cases of typhoid fever was confirmed by a common bacteriophage type, denoted "degraded Vi resembling O," in the S. typhi isolates. This phage type is rare in the western hemisphere but common in the endemic area from which the carrier had emigrated. The high level of Vi antibody in the asymptomatic carrier, in contrast to the lower levels in the convalescentand postimmunization-phase sera, facilitated the identification of the source infection in this outbreak. This radioimmunoassay offers a rapid and standardized method for identifying carriers of S. typhi.

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Objectives The study aims to examine whether a higher proportion of current and former smokers reported having an oral cancer screening (OCS) exam in the past year compared with never smokers in Maryland between 2002 and 2008. Methods Secondary analysis of the Maryland Cancer Surveys (conducted in 2002, 2004, 2006, and 2008), population-based, random-digit-dial surveys on cancer screening among adults age 40 years and older. Of 20,197 individuals who responded to the surveys, 19,054 answered questions on OCS and smoking. Results are weighted to the Maryland population. Results Self-reported OCS in the past year increased from 33 percent in 2002 to 40 percent in 2008. Screening among never and former smokers increased from about 35 percent to 42 percent and from 35 percent to 43 percent, respectively; screening among current smokers remained between 23 percent and 25 percent. In the adjusted analysis, current smokers had decreased odds of screening compared with never smokers; no significant difference was observed between former and never smokers. When the variable dental visit in the last year was included in the adjusted analysis, it became the strongest predictor of OCS. Conclusions Between 2002 and 2008, self-reported OCS in the last year increased among former and never smokers, but remained unchanged for current smokers. A visit to a dental professional attenuated the difference in OCS between current and never smokers. Dental visit in the last year was the strongest predictor of OCS.