OBJECTIVE To explore the isolation,distributive characteristics and drug resistance of Acinetobacter baumannii producing AmpC enzyme in nosocomial infection.METHODS The distributive sections and infected parts of 42 A.baumannii strains in nosocomial infection were analyzed,and three dimensional test was used to(detect) AmpC enzyme.RESULTS Among them 18(42.86%) strains were AmpC positive.Among 40 strains of A.baumannii in non-nosocomial infection,6(15.00%) strains were AmpC positive.A.baumannii in nosocomial(infection) in clinical sections was mainly discovered in burn department,and the respiratory tract and skin soft tissue were the main infected sites(90%).The drug resistance in nosocomial infection was obviously higher than that of A.baumannii in non-nosocomial one.CONCLUSIONS The isolated rate and drug resistance rate of A.baumannii producing AmpC enzyme are rather high in nosocomial infection.It′s(neccessary) to take measures to prevent the nosocomial infection caused by A.baumannii.

BACKGROUND:Human umbilical cord mesenchymal stem cells (hUC-MSCs) may be mutated duringin vitro culture based on the spontaneous malignant transformation of adult stem cells and tumor stem cell theory, and there may be a risk of tumorigenesis after in vivo transplantation. Therefore, to establish and perfect the in vitro safety testing procedures will actively promote the clinical application of stem cells. OBJECTIVE:To investigate the tumorigenic mechanism of hUC-MSCs and the expression level of DNA methyltransferase (DNMTs) in hUC-MSCs. METHODS:Primary hUC-MSCs were isolated and expanded by tissue adherent culture. 3-Methycholanthrene was used to cause the malignant transformation in hUC-MSCs (experimental group), followed by morphological observation and tumorigenesis experiment in nude mice. Then, the tumor tissues were obtained and identified by pathological examination and primary cell culture, and the levels of DNMTs mRNA in hUC-MSCs treated with 3-methycholanthrene and dimethyl sulfoxide (control group) were detected by real-time RT-PCR and compared. RESULTS AND CONCLUSION:hUC-MSCs treated with 3-methycholanthrene led to malignant transformation, which showed malignant growth and non-integer ploidy changes in the cell nuclei, and formed a malignant tumor in immune-deficient mice after injection. Compared with the control group, the cells in the experimental group showed higher expression of DNMTs mRNA as detected by real-time RT-PCR. To conclude, hUC-MSCs can trigger malignant transformation in the morphology and the epigenetics under certain conditions. DNMTs can be a candidate for prevention against malignant transformation of transplanted stem cells.

Timely reporting, effective analyses and rapid distribution of surveillance data can assist in detecting the aberration of disease occurrence and further facilitate a timely response. In China, a new nationwide web-based automated system for outbreak detection and rapid response was developed in 2008. The China Infectious Disease Automated-alert and Response System (CIDARS) was developed by the Chinese Center for Disease Control and Prevention based on the surveillance data from the existing electronic National Notifiable Infectious Diseases Reporting Information System (NIDRIS) started in 2004. NIDRIS greatly improved the timeliness and completeness of data reporting with real time reporting information via the Internet. CIDARS further facilitates the data analysis, aberration detection, signal dissemination, signal response and information communication needed by public health departments across the country. In CIDARS, three aberration detection methods are used to detect the unusual occurrence of 28 notifiable infectious diseases at the county level and to transmit that information either in real-time or on a daily basis. The Internet, computers and mobile phones are used to accomplish rapid signal generation and dissemination, timely reporting and reviewing of the signal response results. CIDARS has been used nationwide since 2008; all Centers for Disease Control and Prevention (CDC) in China at the county, prefecture, provincial and national levels are involved in the system. It assists with early outbreak detection at the local level and prompts reporting of unusual disease occurrences or potential outbreaks to CDCs throughout the country.

OBJECTIVETo explore the effect of signal strength indictor (SSI) in improving sensitivity of China Infectious Diseases Automated-alert and Response System (CIDARS).

METHODSDiarrhea cases in 2007-2011 and early warning signals in 2010-2011 were selected by using random digital table method. Then, SSI and event-related ratio (ER) were calculated. The relationship between ER and SSI was analyzed, and the effect of SSI on ER was explored by using multiple logistic regression analysis.

RESULTS9 620 early warning signals in 2010-2011 were generated in two years. Of these, 74, or 0.77% were defined as suspected outbreak signal. The median of SSI related with suspected outbreak signal was 4.0, which was much higher than non-suspected outbreak signal (1.7). ER was significantly correlated with SSI (r=0.917). SSI classification has a good correlation between the ER, ER exceeded 20 after SSI reached 20. The multivariate logistic regression analysis showed OR of SSI related with suspected outbreak signal was 2.52 (95% CI 2.04-3.12). Compared with non-epidemic season, the relationship of SSI and ER in epidemic season was much higher.

CONCLUSIONSSI was closely related with ER. The relationship was much closer in large scale outbreak and epidemic season, and compared to non-epidemic,the effect of epidemic season is more obvious.

China ; Communicable Diseases ; diagnosis ; epidemiology ; Diarrhea ; diagnosis ; epidemiology ; Disease Outbreaks ; Humans ; Population Surveillance

Objective To compare the bio-medical parameters in SIV infected Chinese rhesus monkeys with diverse disease progression,by which the pathogenesis of simian AIDS were to be investigated.Methods Sixteen Chinese rhesus monkeys were inoculated intravenously with SIVmac239 and followed-up for 18 months.Based on their progression patterns and plasma viral loads,animals were divided into 3 groups,including 1 rapid progressor( RP),13 normal progressors(NP),and 2 elite controllor(EC).Their parameters of haematology,virology,immunology and pathology were examined and compared. Results Compared with other animals,RM449(RP) showed higher viral load,unresponsive humoral immunity,and higher level of auto-antibodies against lymph node,thymus,and spleen.Additionally,its effector memory CD4 count was lower,with the transformation progress being blocked-like from naive/central memory subsets to effector memory subset,as the flow-cytometry assay showed.Notable decrease in its peripheral B cell was also observed,especially to the sub-population of tissue-like memory B cells and activated memory B cells.Pathological examination showed the depletion of lymphoid tissue,atrophy of spleen and loss of thymus.Moreover,most of these parameters of RM450 and RM453 (EC) changed opposite to that of RP.Conclusion The hallmarks of RM449 were higher viraemia and lower SIV specific IgG level,which may due to the disturbance of T cells and B cells development and differentiation.Moreover,destructions of organs of the immune system may contribute to the disturbance.Our study suggest that the change of micro-environments of thymus induced by SIV infection,which is necessary in T cell and B cell development and differentiation,may contribute at least partially to the AIDS pathogenesis.

OBJECTIVEProviding evidences for further modification of China Infectious Diseases Automated-alert and Response System (CIDARS) via analyzing the outbreak detection performance of Moving Percentile Method (MPM) by optimizing thresholds in different provinces.

METHODSWe collected the amount of MPM signals, response results of signals in CIDARS, cases data in nationwide Notifiable Infectious Diseases Reporting Information System, and outbreaks data in Public Health Emergency Reporting System of 16 infectious diseases in 31 provinces in Chinese mainland from January 2011 to October 2013. The threshold with the optimal sensitivity, the shortest time to detect outbreak and the least number of signals was considered as the best threshold of each disease in Chinese mainland and in each province.

RESULTSAmong all the 16 diseases, the optimal thresholds of 10 diseases, including dysentery, dengue, hepatitis A, typhoid and paratyphoid, meningococcal meningitis, Japanese encephalitis, scarlet fever, leptospirosis, hepatitis, typhus in country level were the 90(th) percentile (P90), which was the same as provincial level for those diseases.For the other 6 diseases, including other infectious diarrhea, influenza, acute hemorrhagic conjunctivitis, mumps, rubella and epidemic hemorrhagic fever, the nationwide optimal thresholds were the 80th percentile (P80), which was different from that by provinces for each disease. For these 6 diseases, the number of signals generated by MPM with the optimal threshold for each province was decreased by 23.71% (45 557), 15.59% (6 124), 14.07% (1 870), 9.44% (13 881), 8.65% (1 294) and 6.03% (313) respectively, comparing to the national optimal threshold, while the sensitivity and time to detection of CIDARS were still the same.

CONCLUSIONOptimizing the threshold by different diseases and provinces for MPM in CIDARS could reduce the number of signals while maintaining the same sensitivity and time to detection.

China ; Communicable Diseases ; Disease Notification ; Disease Outbreaks ; prevention & control ; Humans ; Population Surveillance ; methods

OBJECTIVEFor providing evidences for further modification of China Infectious Diseases Automated-alert and Response System (CIDARS) by comparing the early-warning performance of the temporal model and temporal-spatial model in CIDARS.

METHODSThe application performance for outbreak detection of temporal model and temporal-spatial model simultaneously running among 208 pilot counties in 20 provinces from 2011 to 2013 was compared; the 16 infectious diseases were divided into two classes according to the disease incidence level; cases data in nationwide Notifiable Infectious Diseases Reporting Information System was combined with outbreaks reported to Public Health Emergency Reporting System, by adopting the index of the number of signals, sensitivity, false alarm rate and time for detection.

RESULTSThe overall sensitivity of temporal model and temporal-spatial model for 16 diseases was 96.23% (153/159) and 90.57% (144/159) respectively, without significant difference (Z = -1.604, P = 0.109), and the false alarm rate of temporal model (1.57%, 57 068/3 643 279) was significantly higher than that of temporal-spatial model (0.64%, 23 341/3 643 279) (Z = -3.408, P = 0.001), while the median time for detection of these two models was not significantly different, which was 3.0 days and 1.0 day respectively (Z = -1.334, P = 0.182).For 6 diseases of type I which represent the lower incidence, including epidemic hemorrhagic fever,Japanese encephalitis, dengue, meningococcal meningitis, typhus, leptospirosis, the sensitivity was 100% for both models (8/8, 8/8), and the false alarm rate of both temporal model and temporal-spatial model was 0.07% (954/1 367 437, 900/1 367 437), with the median time for detection being 2.5 days and 3.0 days respectively. The number of signals generated by temporal-spatial model was reduced by 2.29% compared with that of temporal model.For 10 diseases of type II which represent the higher incidence, including mumps, dysentery, scarlet fever, influenza, rubella, hepatitis E, acute hemorrhagic conjunctivitis, hepatitis A, typhoid and paratyphoid, and other infectious diarrhea, the sensitivity of temporal model was 96.03% (145/151), and the sensitivity of temporal-spatial model was 90.07% (136/151), the number of signals generated by temporal-spatial model was reduced by 59.36% compared with that of temporal model. Compared to temporal model, temporal-spatial model reduced both the number of signals and the false alarm rate of all the type II diseases;and the median of outbreak detection time of temporal model and temporal-spatial model was 3.0 days and 1.0 day, respectively.

CONCLUSIONOverall, the temporal-spatial model had better outbreak detection performance, but the performance of two different models varies for infectious diseases with different incidence levels, and the adjustment and optimization of the temporal model and temporal-spatial model should be conducted according to specific infectious disease in CIDARS.

China ; Communicable Diseases ; Disease Notification ; Disease Outbreaks ; prevention & control ; Humans ; Models, Theoretical ; Population Surveillance ; methods ; Spatio-Temporal Analysis

OBJECTIVETo analyze the implement performance of China Infectious Diseases Automated-alert and Response System (CIDARS) of 31 provinces in mainland China, and to provide the evidences for further promoting the application and improvement of this system.

METHODSThe amount of signals, response situation and verification outcome of signals related to 32 infectious diseases of 31 provinces in mainland China in CIDARS were investigated from 2011 to 2013, the changes by year on the proportion of responded signals and timeliness of signal response were descriptively analyzed.

RESULTSA total of 960 831 signals were generated nationwide on 32 kinds of infectious diseases in the system, with 98.87% signals (949 936) being responded, and the median (the 25(th) percentile to the 75(th) percentile (P25-P75) ) of time to response was 1.0 (0.4-3.3) h. Among all the signals, 242 355 signals were generated by the fixed-value detection method, the proportion of responded signals was 96.37% (62 349/64 703), 98.75% (68 413/69 282) and 99.37% (107 690/108 370), respectively, and the median (P25-P75) of time to response was 1.3 (0.3-9.7), 0.8(0.2-4.9) and 0.7 (0.2-4.2) h, respectively. After the preliminary data verification, field investigation and laboratory test by local public health staffs, 100 232 cases (41.36%) were finally confirmed.In addition, 718 476 signals were generated by the temporal aberration detection methods, and the average amount of signal per county per week throughout the country were 1.53, and 8 155 signals (1.14%) were verified as suspected outbreaks. During these 3 years, the proportion of signal response was 98.89% (231 149/233 746), 98.90% (254 182/257 015) and 99.31% (226 153/227 715), respectively, and the median (P25-P75) of time to response was 1.1 (0.5-3.3), 1.0 (0.5-2.9) and 1.0 (0.5-2.6) h, respectively.

CONCLUSIONFrom 2011 to 2013, the proportion of responded signals and response timeliness of CIDARS maintained a rather high level, and further presented an increasing trend year by year. But the proportion of signals related to suspected outbreaks should be improved.

China ; Communicable Diseases ; Disease Notification ; Disease Outbreaks ; prevention & control ; Humans ; Population Surveillance ; methods

Objective To analyze the viral etiologies of hospitalized pneumonia patients aged less than five years in six provinces during 2009-2012,and to describe the seasonality of the detected viral etiologies. Methods Eight hospitals were selected in six provinces from a national acute respiratory infection surveillance network. Demographic information,clinical history and physical examination,and laboratory testing results of the enrolled hospitalized patients aged less than five years with pneumonia,including respiratory syncytial virus (RSV),human influenza virus, adenoviruses(ADV),human parainfluenza virus(PIV),human metapneumovirus(hMPV),human coronavirus(hCoV)and human bocavirus(hBoV)were analyzed. The viral etiology spectrum of the enrolled patients was analyzed by age-group,year,and seasonality of the detected viral etiologies were described. Results 4 508 hospitalized children less than five years old,with pneumonia from 8 hospitals were included,and 2 688(59.6%)patients were positive for at least one viral etiology. The most frequent detected virus was RSV(21.3%),followed by PIV(7.1%)and influenza(5.2%),hBoV (3.8%),ADV(3.6%)and hMPV(2.6%). The lowest positive rates in hCoV(1.1%). RSV,influenza, PIV,hBoV and hMPV all showed the nature of seasonality. Conclusion RSV was a most common viral etiology in the hospitalized young children less than 5 years of age with pneumonia. Prevention measures should be conducted to decrease its severe impact to the young infants and children in China.

OBJECTIVETo analyze the viral etiologies of hospitalized pneumonia patients aged less than five years in six provinces during 2009-2012, and to describe the seasonality of the detected viral etiologies.

METHODSEight hospitals were selected in six provinces from a national acute respiratory infection surveillance network. Demographic information, clinical history and physical examination, and laboratory testing results of the enrolled hospitalized patients aged less than five years with pneumonia, including respiratory syncytial virus (RSV), human influenza virus, adenoviruses (ADV), human parainfluenza virus (PIV), human metapneumovirus (hMPV), human coronavirus (hCoV)and human bocavirus (hBoV) were analyzed. The viral etiology spectrum of the enrolled patients was analyzed by age-group, year, and seasonality of the detected viral etiologies were described.

RESULTS4 508 hospitalized children less than five years old, with pneumonia from 8 hospitals were included, and 2 688 (59.6%) patients were positive for at least one viral etiology. The most frequent detected virus was RSV (21.3%), followed by PIV (7.1%) and influenza (5.2%), hBoV (3.8%), ADV(3.6%) and hMPV(2.6%). The lowest positive rates in hCoV(1.1%). RSV, influenza, PIV, hBoV and hMPV all showed the nature of seasonality.

CONCLUSIONRSV was a most common viral etiology in the hospitalized young children less than 5 years of age with pneumonia. Prevention measures should be conducted to decrease its severe impact to the young infants and children in China.

Child, Hospitalized ; statistics & numerical data ; Child, Preschool ; China ; epidemiology ; Female ; Humans ; Infant ; Male ; Pneumonia, Viral ; epidemiology ; virology