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Summary Background Healthcare-associated infections (HCAIs) cause significant morbidity and mortality worldwide, and outbreaks are often only identified after they reach high levels. A wide range of data is collected within healthcare settings; however, the extent to which this information is used to understand HCAI dynamics has not been quantified. Aim To examine the use of spatiotemporal analyses to identify and prevent HCAI transmission in healthcare settings, and to provide recommendations for expanding the use of these techniques. Methods A systematic review of the literature was undertaken, focusing on spatiotemporal examination of infectious diseases in healthcare settings. Abstracts and full-text articles were reviewed independently by two authors to determine inclusion. Findings In total, 146 studies met the inclusion criteria. There was considerable variation in the use of data, with surprisingly few studies ( N = 22) using spatiotemporal-specific analyses to extend knowledge of HCAI transmission dynamics. The remaining 124 studies were descriptive. A modest increase in the application of statistical analyses has occurred in recent years. Conclusion The incorporation of spatiotemporal analysis has been limited in healthcare settings, with only 15% of studies including any such analysis. Analytical studies provided greater data on transmission dynamics and effective control interventions than studies without spatiotemporal analyses. This indicates the need for greater integration of spatiotemporal techniques into HCAI investigations, as even simple analyses provide significant improvements in the understanding of prevention over simple descriptive summaries.

Four layer genetic stocks consisting of 3 Ottawa control strains (5, 7, and 10) and a commercial laying stock (CCS) were utilized to evaluate potential changes in behavioral profiles due to the effects of genetic selection through 2 production cycles. The Ottawa strains were started as random bred strains from the crosses of several popular commercial layers in 1950, 1959, and 1972, and the commercial strain used herein was from calendar year 1993, and its ancestors were involved in the formation of all of the random bred strains. The behavior study utilized 2 replicates from each strain that contained 4 cages, 6 hens/cage, for a total of 192 hens. Behavioral observations were recorded on 2 consecutive days beginning at 22 wk of age and every 28 d thereafter during the first production cycle, the molt period, and the second production cycle through 90 wk of age and periodic feather and Hansen's test scores recorded. Behavior profiles were similar between the control strains and the CCS, indicating that long-term genetic selection by commercial egg-type breeding firms to enhance production parameters has had no impact on laying strain behavior patterns. Appetitive behaviors were not affected by strain. During the molt, hens had reduced (P < 0.05) feeding and drinking frequencies in comparison with those observed during the first and second cycles. The data indicated that hens pecked inedible objects at a greater (P < 0.0001) frequency during the first cycle and molt than during the second cycle. Fearfulness scores were only influenced by production phase with the molt having the highest (P < 0.01) score of 3.46. Strain or production phase did not influence the frequency of aggressive and submissive acts.

The hypothesis was proposed that the improved embryonic livability observed when higher incubation temperatures were imposed on eggs stored for 15 d prior to setting might have basis in energy metabolism. To test the hypothesis, fertilized turkey eggs were incubated either for the first 2 wk of development (experiment 1) or only the first week of development (experiment 2) at 37.8 degrees C compared with controls incubated at 37.5 degrees C. In both experiments, eggs were stored for either 15 or 3 d prior to setting. Viable embryos were selected randomly from each storage-by-incubation period treatment combination at 25 to 28 d of incubation and were sampled for blood, heart, and skeletal muscle tissues. Tissues were weighed and assayed subsequently for glucose or glycogen content. In experiment 2, the randomly selected embryos from each treatment combination were sampled at 7, 14, 21, and 28 d of incubation. Embryos at 7 and 14 d were assayed on a whole body basis, whereas at 21 and 28 d the bodies were dissected, and heart, liver, and skeletal muscle tissues were weighed and assayed for glycogen and lactate. Blood samples were collected between 25 and 28 d of incubation as in experiment 1 and assayed for glucose, creatine kinase, lactate dehydrogenase, and thyroid hormone concentrations. In both experiments, accelerated development was noted due to higher temperature and enhanced embryonic carbohydrate metabolism, and elevated thyroid hormone concentrations were observed compared with controls. It was concluded that a possible mechanism for the improved livability of faster growing embryos observed after prolonged egg storage might be due to better utilization of carbohydrate.

A new flux-transfer technique has been used to measure the total neutron flux to an accuracy of 5% at the Army Pulse Radiation Facility (APRF) fast pulse reactor. Use is made of 239Pu-loaded fission chambers developed by the National Bureau of Standards (NBS) and calibrated against a 252Cf source at NBS. Advantages of the method are that it uses a standard source for calibration, that it is independent of errors in fission foil masses and that the effects of cross-section errors are minimized by the need to use only cross-section ratios. Therefore, the method can serve as a calibration procedure that is readily amenable to interlaboratory comparison. The results show that previous dosimetry is 18% too high in the APRF in-core irradiation facilities, and 21% too high at core surface. Flux calibrations have also been made by using 237Np, several uranium isotopes, and the 32S(n,p)32P reaction. Fluxes from all measurements agree to 7%. The (>10 keV/>3 Mev) flux ratios determined for the glory holes and leakage spectra are 8.4 ± 0.6 and 7.3 ± 0.5, respectively.