Protracted hospital-based epidemics of urinary tract infection and bacteremia due to multiply resistant gram-negative bacilli have become an increasingly common and serious problem. Failure to control such outbreaks stems partly from inability to eradicate a key reservoir, the catheterized bladder. Since eradication of bacteriuria in noncatheterized patients can be achieved with single doses of antimicrobials and correlates with urinary rather than with serum antibiotic concentrations, drugs to which an organism appears resistant by discdiffusion testing, if excreted in the urine in high concentrations, might also prove useful in eliminating catheter-associated bacteriuria. Alternatively, urinary antiseptics, for which antimicrobial sensitivity testing is not usually done, might be effective. To test this hypothesis we determined the minimum inhibitory concentrations (MICs) of 45 multiply resistant Proteus, Serratia, Klebsiella, and Pseudomonas strains isolated in 13 recent epidemics of nosocomial urinary tract infections against 10 selected antimicrobials and urinary antiseptics, and compared these MICs with expected urinary concentrations of each drug. For each genus tested, MICs for at least two antimicrobials or urinary antiseptics were well below easily achievable urinary drug concentrations. Zone size criteria often predicted which drugs had MICs below achievable urinary levels. Little difference was found between MICs determined in Mueller-Hinton broth and in urine. During an epidemic, simultaneous treatment of all patients with bacteriuria by administration of a urinary antiseptic or an antibiotic that achieves high concentrations in urine, in conjunction with brief catheter removal, might prove useful in controlling any further infection.

We compared the cost of antibody screening and the projected cost for hepatitis B vaccination of antibody-negative individuals at hospitals with “high prevalence” and “low prevalence” rates for hepatitis B virus antibodies among their employees. The use of hepatitis B core antibody for screening and subsequent hepatitis B vaccination of antibody-negative personnel was most cost-effective for hospitals considered to have high prevalence for hepatitis B virus antibodies among its staff, although use of hepatitis B surface antibody in this setting only increased costs by 1.4%. In a hospital with low prevalence for hepatitis B virus antibodies among its staff, use of hepatitis B surface antibody and subsequent vaccination of antibody-negative individuals was the most cost-effective approach, while use of hepatitis B core antibody for the above purposes would have increased costs by 3.4%. The use of both hepatitis B surface antibody and core antibody in either setting followed by immunization was least economical, as costs were increased by 13% and 13.5% respectively.

We concluded that hepatitis B core antibody should be used for screening in hospitals with high prevalence for hepatitis B virus antibodies among employees while hepatitis B surface antibody be used for screening in hospitals with low prevalence for hepatitis B virus antibodies among employees. A prediction of high and low prevalence for hepatitis B virus antibodies in hospital personnel may be made by knowledge of the distribution in ethnicity of staff.

Exploratory Data Analysis offers a set of graphical and statistical tools to find the full meaning from data sets. The user visualizes, analyzes, and transforms data distributions with these tools. Graphs reveal relationships between variables; the residuals left after fitting data show the adequacy of the model. Without this careful examination and understanding of the data, rote data analysis using standard statistical tests can give misleading results. Exploratory Data Analysis has its own set of pitfalls and must be used with confirmatory statistics and studies. Increasing power and resolution in personal computers enables modern statistical software to make these methods widely accessible. By easily moving between data and their graphic representation, analysis can be comprehensive without being tedious. Exploratory Data Analysis can add an exciting and useful tool to the epidemiologist's repertoire. This article illustrates several tools from an evolving list.

Exposure investigations are labor intensive and vulnerable to recall bias. We developed an algorithm to identify healthcare personnel (HCP) interactions from the electronic health record (EHR), and we evaluated its accuracy against conventional exposure investigations. The EHR algorithm identified every known transmission and used ranking to produce a manageable contact list.

Background: Blood culture testing is an important diagnostic tool in identifying the presence of microbes in the bloodstream. Tests are frequently contaminated, leading to false-positive results. Blood culture contamination can result in unnecessary antibiotic treatment, extended hospital length of stay, and patient exposure to hospital-acquired conditions. Methods: St. Mary’s Regional Medical Center (SMRMC) in Russellville, Arkansas, struggled with blood-culture contamination rates, with an average of 6.8% from 2014 to 2018. Ongoing staff education yielded a reduction to an average of 5%. In an effort to reduce the contamination rates, our facility elected to try a novel specimen diversion device. Laboratory and emergency department (ED) staff were educated on the diversion device prior to the initiation of the trial period. Compliance with the diversion device averaged 70%–75% during the trial period. Monitoring of contaminations was added to our daily safety huddle to provide a quick turnaround time for false-positive education to specific clinical staff. Results: The results were significant, with a decrease in contamination rates from 4.93% to 1.66%—a 66% reduction. Improved blood culture testing has several advantages: best practice for patient care is first and foremost, along with other financial benefits for the facility. Several articles have estimated the cost of a contaminated culture to be $3,000–$10,000 per event; SMRMC has adopting an estimated cost of $4,000. The number of cultures at our hospital averages ~4,400 per year, and these results suggest a savings of >$500,000 per year (as contaminations on an annual basis fell from 217 to 73). With this intervention, 144 patients were spared from receiving unnecessary antibiotics as a result of a false-positive blood culture testing. Conclusions: We conducted a brief analysis to determine whether there was any obvious change in length of stay for patients with a false-positive blood culture compared to those with true negative results. In analyzing data for 3 different months, patients with contaminated cultures spent an average of 3.97 additional days in the facility. In conclusion, the implementation of this specimen diversion device significantly lowered our contamination rates, was integrated into practice, and has provided clinical and financial benefits.

Funding: None

Disclosures: None