Objective To investigate the prevalence of healthcare-associated infection(HAI)in a children's spe-cialty hospital in Guangzhou in 2014.Methods A cross-sectional survey was undertaken to investigate the preva-lence of HAI among all hospitalized patients on September 17,2014.Results A total of 997 patients were investiga-ted,30 patients developed 32 times of HAI,HAI rate and HAI case rate were 3.01% and 3.21% respectively. The main infection sites were upper respiratory tract(n= 11,34.38% );the departments with higher HAI prevalence rates were intensive care unit(ICU,3 .99% )and pediatric internal medicine department(3 .60% );the rate of etio-logical examination in patients with HAI accounted for 93 .33% ,a total of 24 strains of pathogens were isolated,6 of which were virus (25 . 00% ),6 were fungi (25 . 00% ),11 were bacteria (45 . 83% ),and 1 was Chlamydia (4.17% ). The main bacteria were Staphylococcusaureus (n= 3,27.27% )and Staphylococcusepidermidis (n= 3, 27.27% );a total of 451 (45.24% )patients received antimicrobial agents on the investigation day,67.41% of whom received therapeutic use of antimicrobial agents,19.73% received prophylactic use,and 12.86% received both therapeutic and prophylactic use;mono-drug application accounted for 82 .26% ,the percentage of bacterial de-tection among patients with therapeutic antimicrobial use (including combination of therapeutic and prophylactic use)was 82.60% .Conclusion Management of key departments and key sites of HAI should be strengthened in children's specialty hospital,antimicrobial agents should be used rationally,so as to protect the safety of children.

Objective To investigate the hygienic status of large bottles of medical ultrasonic coupling gel in medical institution.Methods From February 2012 to April 2016, microbial contamination of large bottles of medical ultrasonic coupling gel in a women and children''s hospital was investigated and analyzed through on-the-spot random sampling and detection method.Results A total of 170 large bottles of medical ultrasonic coupling gel specimens were collected, 25 specimens were qualified, the qualified rate was 14.71％.Specimens were mainly from inpatient wards(58.24％) and operating departments(21.76％);there was no statistical difference in the qualified rate of specimens in each department(P>0.05).Contamination rates of coupling gel before and after the opening were both>80％, difference was not significant(P>0.05).A total of 145 strains of pathogenic bacteria were isolated, 18 of which were from unopened bottles, and 127 from opened bottles.Burkholderia cepacia was the main strain in both unopened and opened bottles, which accounting for 83.33％ and 54.33％ respectively,in addition, Pseudomonas aeruginosa and Serratia marcescens were also isolated from opened bottles, both were 15.75％, mixed contamination bacteria all included Serratia marcescens Conclusion The total bacteria counts in medical ultrasonic coupling gel in large bottles exceed the standard seriously, the manufacturer should strictly observe the quality control standards, medical institutions should adopt effective cleaning and disinfection measures.

Objective To investigate the feasibility of b value threshold maps based on MRI diffusion weighted imaging ( DWI ) in the diagnosis of pancreatic adenocarcinoma .Methods The preoperative MRI DWI [ b value=0( b0 ) and 1000 ( b1000 ) s/mm2 ] data of 14 patients who were postoperatively histologically confirmed as pancreatic ductal adenocarcinoma from September 2016 to May 2015 admitted in Shanghai Changhai Hospital were retrospectively analyzed .The b value threshold maps were calculated .Computed DWI images at b value of 1500 s/mm2 ( cDWIb1500 ) was calculated based on the scanned DWI images of b 0 and b1000 s/mm2 . The efficacy of DWIb 1000 , b value threshold map and cDWIb 1500 in manifesting pancreatic adenocarcinoma was assessed by a four-point scale .The non-parametric Friedman test was used to compare the three methods , and Conover adjusted method was applied to compare any two of the three methods .Results The conspicuity score of DWIb 1000 , b value threshold map and cDWIb 1500 in showing pancreatic cancer was 2.9 ±0.8, 3.7 ±0.5 and 3.6 ±0.5, respectively, and the differences among the three methods were statistically significant (F=19.5, P value <0.001), but the differences on tumor conspicuity scores of b value threshold map and cDWIb 1500 were not statistically different .Conclusions The calculation of b value threshold map based on DWI images could show pancreatic cancer in high contrast quickly by adjusting window width and window level , and could achieve comparable performance as cDWIb 1500 .