Abstract:The epidemic of 2019-novel-coronavirus(2019-nCoV) has become a global pandemic since the outbreak at the end of 2019. With the deep understanding of characteristics and disease spectrum of 2019-nCoV, new concepts relevant to 2019-nCoV infection are also emerging, some even overturned people's previous understanding of infectious diseases. Combined with the current advance, this paper interprets people concerned hot topics of 2019-nCoV infection.

Abstract:Objective To explore epidemic characteristics of asymptomatic coronavirus disease 2019 (COVID-19) -infected persons. Methods Clustered epidemics involving asymptomatic infected persons in Henan Province were collected and summarized through Chinese Disease Control and Prevention System, epidemic characteristics were analyzed, differences in epidemic characteristics between asymptomatic infected persons and confirmed cases of COVID-19 were analyzed. Results A total of 257 clustered epidemics were reported, 41 of which involved 84 asymptomatic infected persons, accounting for 74.34%(84/113) of asymptomatic infection in the whole province. The clustered epidemics of asymptomatic infected persons distributed in 11 prefectures, involving 208 cases of COVID-19, each epidemic involved an average of 5.07 (2-19) COVID-19 infection cases, 16 (39.02%) had at least 5 COVID-19 infection cases. The discovery of asymptomatic infection was mainly based on clustered epidemic investigation, diagnosis time was later than that of COVID-19 confirmed cases. The proportion of asymptomatic infection among COVID-19 infection in various cities in Henan Province was the highest in Shangqiu City(26.02%). Asymptomatic infected persons and COVID-19 confirmed cases were statistically different in gender distribution and epidemiological history (both P>0.05); differences in constituent ratios of age and occupational distribution were both statistically significant (both P<0.05), asymptomatic infected persons ≤ 40 years old accounted for 58.33%, students and children accounted for 28.57%, and confirmed cases accounted for 21.77% and 4.03% respectively. Conclusion The age and occupational distribution of asymptomatic infected persons are different from those diagnosed with COVID-19. Investigation on clustered epidemic is the main way to find asymptomatic infected persons, effective isolation management of close contacts is the correct and effective prevention and control measure.

Abstract:Objective To explore the effect of heat inactivation on blood transfusion-related infection markers in serum and whole blood specimens. Methods A total of 57 positive serum specimens of hepatitis B virus surface antigen (HBsAg), anti-hepatitis C virus antibody (anti-HCV), anti-human immunodeficiency virus antibody (anti-HIV), anti-Treponema pallidum antibody (anti-TP), HBV DNA and HCV RNA as well as a total of 38 positive whole blood specimens of HBsAg, anti-HCV, anti-TP and HBV DNA were collected. After specimens were inactivated in a water bath at 56℃ for 30 minutes (which can effectively inactivate coronavirus), chemiluminescence and fluorescence quantitative polymerase chain reaction were adopted to detect the corresponding markers, differences among indicators before and after heat inactivation were compared. Results After serum was inactivated, detected results of HBsAg, anti-HCV, anti-HIV, anti-TP, HBV DNA and HCV RNA were not significantly different from those before inactivation (all P>0.05); after whole blood was inactivated, detection results of HBsAg, anti-HCV, anti-TP and HBV DNA were not statistically different from those before inactivation (all P>0.05); Bland-Altman scatterplot showed that all the difference data were within 95% limits of agreement (95% LoA), there was a good consistency in each indicator before and after inactivation. Conclusion The treatment method of heating at 56℃ water bath for 30 minutes has no obvious effect on the detection of blood transfusion-related infection markers, and can be widely used during the epidemic of coronavirus disease 2019.

Abstract:In order to fight against the epidemic of coronavirus disease 2019(COVID-19), medical teams from all over the country went to Wuhan for aiding medical rescue, infection control professionals(ICPs) have become an indispensable power of medical teams. Doing a good job in infection control can effectively reduce the risk of infection of medical team members. Based on the practice, this paper summarizes the experience of carrying out the work of infection control by ICPs in medical teams for aiding Hubei Province, including the establishment of infection control team, conducting infection control training, formulating control measures in the residents, monitoring and disposing infection and exposure, optimizing layout of three region and process of putting on and taking off personal protective equipment(PPE), supervising putting on and taking off PPE, guiding cleaning and disinfection, establishing each infection control system in epidemic period, supervising clinical infection control and so on.

Abstract:Objective To understand 2019-nCoV contamination on hand-touched buttons of alcohol-based hand rub in the isolation ward area of a regional coronavirus disease 2019(COVID-19) treatment hospital, and provide evidence for guiding disinfection in isolation ward area. Methods Hand-touched buttons of alcohol-based hand rub in 5 regions of the isolation ward area (confirmed ward, ward corridor, first buffer room, second buffer room, clean zone) were sampled, and contamination in specimens were detected with reverse transcription polymerase chain reaction (RT-PCR). Results A total of 76 button specimens were collected, 2019-nCoV contamination rate in isolation ward area was 10.53%, contamination rates of buttons in confirmed ward and ward corridor were 14.29% and 12.50% respectively, contamination rates in the first buffer zone, the second buffer zone, and clean zone were all 0%. Conclusion Hand-touched buttons of alcohol-based hand rub in this isolation ward area are seriously contaminated by 2019-nCoV, cleaning and disinfection needs to be strengthened, it is suggested that buttons in isolation ward area should be pressed by the back of the hand, if medical institution is conditional, inductive liquid outlet and hand-washing sensor monitor should be used.

Abstract:Objective To explore the effective training approach of putting on and removing of personal protective equipment(PPE). Methods Health care workers(HCWs) were randomly divided into three groups(group 1:video training; group 2:on-site demonstration training; group 3:one-to-one practical training), training on putting on and removing of PPE was conducted, after the training, three groups of HCWs were checked, training effect was evaluated. Assessment on steps of putting on and removing of PPE was performed by table score and qualitative method (smearing fluorescence powder before removing PPE to judge whether fluorescence powder was contaminated on clothes or skin). Results 169 persons were checked in each group, qualified rate of assessment of group 3 was 85.21%, which was higher than 56.21% of group 2 and 34.32% of group 1; among three categories of posts(nursing, medical technician and doctors), the qualified rate of assessment of nursing was the highest (71.57%, 141/197), and qualified rate of medical technicians was the lowest (42.11%, 64/152); in the assessment of steps of putting on and removing of PPE, the lowest qualification rates were the tightness test of wearing medical mask as well as removing of one-piece protective clothes+hand hygiene (64.69% and 60.95%, respectively). There were statistically significant differences among three groups of trained HCWs, three different job posts, as well as steps of putting on and removing of PPE(all P<0.005). Qualified rate of fluorescence qualitative detection was 69.43%. Conclusion One-to-one training is better than on-site demonstration and video training, more attention should be paid to the tightness test of the medical protective mask during the training, when PPE is being removed, contamination on clothes or skin should be avoided.

Abstract:Objective To compare the incidence of catheter-related bloodstream infection (CRBSI) in adult patients receiving home parenteral nutrition (HPN) through peripherally inserted central catheter (PICC) and central venous catheter (CVC), and provide evidence for selecting suitable venous access devices in HPN patients. Methods Studies about CRBSI incidence in HPN patients were searched by computer from Cochrane Library, JBI Library, PubMed, Embase, Ovid, Web of Science, China Biomedical Literature Database(CBM), VIP Database, Wanfang and China National Knowledge Infrastructure(CNKI) from the establishment to March 2019, Stata 13.0 was used to perform Meta-analysis. Results A total of 1 407 patients in 9 cohort studies were included in the analysis. Meta-analysis results showed that the incidence of CRBSI in HPN patients using PICC was lower than that in HPN patients using CVC (12.14% vs 37.18%, RR=0.42, 95% CI:0.34-0.52). Six literatures reported the incidence of CRBSI per 1 000 catheter days, results showed that incidence of CRBSI in PICC was lower than that in CVC (12.97% vs 37.21%, RR=0.37, 95% CI:0.23-0.60). Subgroup analysis results showed that incidence of CRBSI in patients in PICC group were all lower than CVC group in the following subgroups:different PICC placement groups (ultrasound guidance, X-ray examination, unreported), reported CRBSI diagnostic method group, different vascular catheterization day groups (reported group and unreported group), and reported infectious flora species group, differences were all statistically significant (all P<0.05). Conclusion Compared with CVC, the risk of CRBSI is lower when adult HPN patients choose PICC for treatment.

Abstract:Objective To evaluate the carrying status and homology of drug resistance genes of carbapenem-resis-tant Acinetobacter baumannii (CRAB) in a tertiary first-class hospital. Methods 40 strains of CRAB were collected from this hospital between October 2017 and October 2018, carrying status of drug resistance genes was detected by polymerase chain reaction (PCR), homology was analyzed by pulsed-field gel electrophoresis (PFGE). Results The resistance rate of 40 strains of CRAB to most antimicrobial agents was about 90%, resistance rate to tigecycline was relatively low (2.9%, intermediate resistance was not included). Detection rate of drug resistance gene ADC was 100%, detection rates of OXA-51 and qacE△1-sull were 90%(n=36 strains) and 80.0%(n=32 strains) respectively, KPC gene was not found. Each CRAB strain was detected 2-8 kinds of resistance genes, and 37.5% of strains (n=15 strains) were detected 6 kinds of resistance genes; among the detected drug resistance gene combinations, 29 strains (72.5%) were simultaneously detected ADC+OXA-23+OXA-51 genes, 26 strains (65.0%) were detected ADC+intl1+qacE△1-sull genes, 19 strains(47.5%) were detected ADC+qacE△1-sull+ant(3″) -Ⅰ genes, 11 strains(27.5%) were detected ADC+ant(3″) -Ⅰ+aac(3) -Ⅰ genes. 19 different types were divided by PFGE homology detection, each type contained 1-9 strains, including 9 strains of type A5 and 8 strains of type A18, mainly from intensive care unit. Conclusion CRAB is highly resistant to common clinical antimicrobial agents, OXA-23 and OXA-51 are most likely to be the main causes of the resistance of AB in this hospital, homology analysis revealed the presence of CRAB HAI in different wards in this hospital.

Abstract:Objective To explore the homology of carbapenem-resistant Klebsiella pneumoniae (CRKP) strains from patients and environment in an intensive care unit (ICU) of a hospital, and provide theoretical basis for the prevention and control of healthcare-associated infection(HAI). Methods CRKP strains continuously isolated from patients and environment in ICU in a tertiary first-class hospital between September and December 2017 were collected, drug resistance phenotype and carbapenemase genes were detected, molecular homology analysis was performed with multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). Results A total of 10 strains of CRKP were collected, 9 of which were isolated from clinical infection specimens of 5 patients, and 1 was isolated from the panel of the barotherapy instrument. 10 strains all carried KPC gene; MLST types were all ST11; there were 5 types of PFGE bands, 5 strains had identical bands, which were epidemic strains, 1 strain was only 1 band different from epidemic strain, the other 4 strains had similar band types, but they were significantly different from that of the epidemic strain. Drug resistance phenotype, PFGE type and ST type of 1 CRKP strain isolated from panel of barotherapy instrument was identical with 4 CRKP strains from patients, and was considered as HAI due to instrument sharing. PFGE band type of CRKP strains isolated from the abdominal drainage fluid and blood specimen of the same patient were exactly the same, which was speculated that CRKP might be infected bloodstream through the abdominal cavity. Conclusion PFGE and MLST are of great significance to clarify bacteria transmission route of HAI, individual bacterial infection route and genetic variation, which is conductive to cutting off infection route and strongly guiding the control of multidrug-resistant organism transmission.

Abstract:Objective To understand the clinical characteristics, treatment and prognosis of patients with infective endocarditis (IE), and provide reference for the early diagnosis and treatment of IE. Methods Clinical data, isolated pathogens, treatment and prognosis of patients with IE diagnosed in Xiangya Hospital from January 2009 to December 2009 were analyzed retrospectively. Results A total of 430 patients who met the diagnostic criteria of IE were included, most of them were males (n=289, 67.2%). The average age was (40.3±15.1) years. 284 patients (66.0%) had no underlying heart disease, 146 (34.0%) had underlying heart disease, 115 (26.7%) had congenital heart disease, 23 (5.3%) had rheumatic heart disease, and 8 (1.9%) had non-rheumatic heart valve disease. The main clinical manifestations of IE were fever (n=336, 78.1%), anemia (n=381, 88.6%) and heart murmur (n=383, 89.1%); the most common complication was embolism (21.4%), followed by heart failure (18.8%). There were 151 cases of valve prolapse, 88 cases of valve stenosis, 347 cases of valve insufficiency, mostly were aortic valve insufficiency (n=134), 72 cases were with two or more valve insufficiency; positive rate of blood culture was 44.9%, Streptococcus spp.was the most common pathogen (119 strains, 61.7%), followed by Staphylococcus spp., (41 strains, 21.2%). 319 patients (74.2%) with IE were operated, mortality was 10.2%, the recovery rate of patients receiving drug therapy combined with surgery was higher than that of patients only receiving drug therapy(95.3% vs 64.9%,P<0.001). Conclusion At present, IE is common in patients with underlying heart disease, the most common pathogen is Streptococcus spp., anti-infective treatment is the basis of IE treatment, early surgery can reduce the in-hospital mortality.

Abstract:Objective To understand the effect of EV71 vaccination on the epidemiology and pathogen of hand-foot-and-mouth disease (HFMD), and provide scientific basis for the prevention and treatment of HFMD. Methods Data of children with HFMD in a hospital from 2014 to 2018 were collected, SPSS 18.0 software was used to analyze the data, epidemiological characteristics and change in pathogens of HFMD in hospitalized children before and after EV71 vaccination were compared. Results A total of 7 099 children with HFMD were admitted in the hospital, including 6 339 cases of common type and 1 570 cases of severe type, compared with children before EV71 vaccination, the number of hospitalized children with HFMD after vaccination decreased, proportion of severe cases decreased (χ²=56.27, P<0.001). Incidence of HFMD in boys was higher than girls, onset age was still dominated by infants under 5 years old, but the number of severe cases in each age group all decreased; there were two onset peaks in the whole year, which was May-July and September-November respectively; common cases were mainly EV71/CoxA16 infection, while severe cases were mainly EV71 infection. Conclusion The dominant pathogen of HFMD changes significantly after EV71 vaccination, and proportion of severe cases decrease significantly, EV71 vaccine is worth to be popularized and applied. In order to provide a more powerful basis for the prevention and treatment of HFMD, it is necessary to further develop the typing detection of non-EV71/CoxA16 enteroviruse.

Abstract:Objective To understand the implementation of environmental disinfection in medical institutions(MIs) in China, provide scientific basis for the implementation and revision of Regulation of disinfection technique in healthcare settings (WS/T 367-2012). Methods By multi-stage stratified sampling method, 168 MIs in 6 pro-vinces were selected, monitoring results of disinfection mode, frequency and efficacy of air and object surface in general wards and high risk departments were surveyed, filled and reported on internet by full-time staff of infection management in MIs. Results A total of 163 MIs participated in the survey, 2 of which didn't open general wards. 75 (46.58%) MIs disinfected air in general wards, 42 (56.00%) disinfected with ultraviolet light, 31 (41.33%) only performed terminal disinfection or disinfected when necessary, 98 (60.87%) regularly disinfected object surface in general wards, 94 (95.92%) disinfected once or twice a day; 73 (45.34%) MIs monitored the effect of environmental disinfection in general wards, 47 (64.38%) of which monitored at least once per quarter. 141 (86.50%) MIs disinfected air in high risk departments, 122 (86.52%) of which disinfected twice a day; 163 (100%) MIs disinfected object surface of high risk departments, 134 (82.21%) of which disinfected at least twice a day; 161 (98.77%) MIs regularly monitored the effect of environmental disinfection in high risk departments, 111 (68.94%) of which monitored once a quarter. Conclusion The issuing of Regulation of disinfection technique in healthcare settings (WS/T 367-2012) has promoted the environmental cleaning and disinfection in all levels of MIs, but the phenomenon of excessive and insufficient disinfection and monitoring of general wards exists in MIs, which needs further improvement.

Abstract:Objective To analyze risk factors and pathogen distribution of hospital-acquired pneumonia (HAP) in patients with tetanus, and provide reference for clinicians to prevent and control HAP in such patients. Methods Clinical data of patients with tetanus who were admitted to the department of infectious diseases of Affiliated Hospital of Southwest Medical University from January 2014 to June 2019 were collected, patients were divided into two groups according to whether they had developed HAP, distribution of pathogens was analyzed, and risk factors for HAP in patients with tetanus were statistically analyzed. Results Of 75 patients with tetanus, 44 (58.7%) had HAP, 11 death patients all developed HAP. Univariate analysis on risk factors for HAP in patients with tetanus showed that the proportion of age ≥ 60 years, long-term smoking, chronic lung disease, Ablett grade ≥ Ⅲ and tracheo- tomy in patients in HAP group were all higher than those in non-HAP group (all P<0.05); logistic regression analysis showed long-term smoking(OR=7.00, 95% CI:1.17-41.91), chronic lung disease(OR=9.84,95% CI:1.37-70.52), Ablett grade ≥ Ⅲ (OR=24.53, 95% CI:3.81-157.76) were independent risk factors for HAP in patients with tetanus. 24 strains of pathogens were isolated from 44 patients, pathogens were mainly Gram-negative bacteria such as Pseudomonas aeruginosa (n=8 strains) and Klebsiella pneumoniae (n=7 strains). Conclusion Incidence of HAP in patients with tetanus is high, pathogens are mainly Gram-negative bacteria. Tetanus patients with long-term smoking, chronic lung disease and Ablett grade ≥ Ⅲ are easily to develop HAP.

Abstract:Objective To explore hospitalization expense and length of hospital stay in patients with healthcare-associated infection(HAI) due to multidrug-resistant organisms(MDROs) in the intensive care unit(ICU). Methods 1 378 patients who were admitted to ICU in a tertiary hospital from October 2017 to December 2018 were recruited as the study objects, 167 of whom had MDROs infection (MDROs group), 1 211 patients without MDROs infection were in non-MDROs group. MDROs group and non-MDROs group were matched in a 1:1 ratio by propensity score matching(PSM), hospitalization expense and length of hospital stay of matched patients were analyzed statistically. Results A total of 166 pairs were successfully matched by using PSM, the successful matching rate was 99.40%, the median length of hospital stay in MDROs group and non-MDROs group were 34 and 16 days respectively, median difference was 18 days, difference between two groups was statistically significant (P<0.001); the total hospitalization expense was 220 205.83 and 93 380.81 Yuan respectively, difference was 126 825.02 Yuan, difference between two groups was statistically significant (P<0.001). Except the expense of image diagnosis, expense of medical service, treatment manipulation, nursing, experimental diagnosis, clinical diagnosis, western medicine and antimicrobial agents in MDROs group were all higher than non-MDROs group (all P<0.05), difference in expense of western medicine between two groups was the largest (63 828.46 Yuan). Conclusion MDROs healthcare-associated infection(HAI) in ICU patients will increase the length of hospital stay and economic burden of patients, preventive and control measures should be taken.

Abstract:目的 探讨根因分析法在消毒供应中心职业暴露中的应用效果。方法 选取某三甲综合医院消毒供应中心的35名护士,47名工人作为研究对象,应用根因分析法分析工作人员的职业暴露事件,找出根因,并制定改进措施。2017年4月—2018年3月为改进前,2018年4月—2019年3月为改进后,比较改进措施实施前后工作人员职业暴露发生的情况。结果 根因分析结果表明,网篮老旧、每年参加培训次数少、操作流程不规范是工作人员发生职业暴露的根本原因。不同网篮新旧程度组护士的职业暴露发生率比较,差异无统计学意义(P>0.05),工人的职业暴露发生率中老旧组高于新增组,差异有统计学意义(P<0.05)。不同培训次数护士的职业暴露发生率比较,差异无统计学意义(P>0.05),工人的职业暴露发生率中培训次数<5次的高于≥5次,差异有统计学意义(P<0.05)。操作流程不规范组护士、工人的职业暴露发生率均高于操作流程规范组,差异均有统计学意义(均P<0.05)。改进前共有10名(28.57%)护士,19名(40.43%)工人发生职业暴露,职业暴露次数为护士26例次,工人44例次。改进后共有5名(14.29%) 护士,9名(19.15%)工人发生职业暴露,职业暴露次数为护士6例次,工人 13例次。改进前后护士的职业暴露发生率比较,差异无统计学意义(P=0.145),改进前后工人的职业暴露发生率比较,差异有统计学意义(P=0.024)。结论 利用根因分析法可找出消毒供应中心工作人员职业暴露的根本原因,管理人员可通过新增网篮、加强培训及规范流程等措施减少工作人员职业暴露的发生。

Abstract:In recent years, graphene oxide(GO) -based composite materials have been increasingly used in biomedical field. Compared with pure GO, GO-based composite materials have better biological safety while achieving more stable antibacterial properties. In this paper, research status and related application in antibacterial field of GO-based composite materials is reviewed from the aspects of antibacterial mechanism and biosafety, so as to provide reference for the development and application of GO-based composite materials in antibacterial field.