Communicable Diseases ; transmission ; Decision Support Techniques ; Humans ; Models, Theoretical ; Risk Factors

Communicable Diseases ; epidemiology ; transmission ; Environmental Monitoring ; Epidemiologic Factors ; Forecasting ; Humans ; Models, Theoretical ; Risk Assessment

A simulation experiment was carried out by applying the simulation model to spread of influenza A (H1N1) in communities with different population density. Population at the community-level was divided into susceptible, infected and recovered ones, according to the susceptive-infective-removal (SIR) model, and the age structure of the population was set on the basis of data from the Fifth Population Census. Contact and moving of the individuals were based on the Network Random Contact Model and the mortality and infection mode were established in line with the influenza A (H 1N 1) medical description. The results of an example analysis showed that the infection rate was closely related to the density of the community-based population while the rate on early infection grew rapidly. Influenza A (H1N1) seemed more likely to break out in the community with population density of over 50/hm2. Comparative tests showed that vaccination could effectively restrain the spread of influenza A (H1N1) at the community level. Conclusion Population density,and the coverage of influenza vaccination were risk factors for influenza A (H1N1) epidemics.Results of the experiment showed of value, for prevention and vaccination on this topic.

Objective To assess the accuracy of mixed venous oxygen saturation ( S(-v)O2 ) in reflecting the change in CO during off-pump coronary artery bypass grafting (OPCABG) .Methods Twenty-five NYHA Ⅰ -Ⅲ patients of both sexes, aged 50-75 yr, weighing 55-85 kg, undergoing OPCABG, were studied. Anesthesia was induced with midazolam, fentanyl, etomidate and pipecuronium and maintained with propofol infusion and intermittent iv boluses of fentanyl and pipecuronium supplemented with isoflurane if necessary. The patients were mechanically ventilated (VT 8-10 ml/kg, RR 8-10 bpm, I:E 1:2). PETCO2 was maintained at 35-45 mm Hg.Radial artery was cannulated and pulmonary catheter was placed. CI, S(-v)O2 and Hb were monitored and recorded before skin incision, during anastomosis with left anterior descending artery (LAD), right coronary artery (RCA)and left circumflex coronary artery (LCX), when the chest was closed, when the patients' body position was changed and the heart was manipulated. S(-v)O2 and CI were scaled immediately after the pulmonary artery catheter was placed and before anastomosing LAD. Results The CO change in S(-v)O2 was real-time and accurate in reflecting the body positioning and elevation of hearts. There was no simultaneous significant change in CI.Conclusion The CO change in S(-v)O2 is real-time and accurate in reflecting the body positioning and elevation of hearts during OPCABG.

Objective To analyze the spatio-temporal process on 2009 influenza A (HlNl) pandemic in Changsha and the influencing factors during the diffusion process. Methods Data were from the following 5 sources, influenza A (HlNl) pandemic gathered in 2009, Geographic Information System (GIS) of Changsha, the broad range of theorems and techniques of hot spot analysis, spatio-temporal process analysis and Spearman correlation analysis. Results Hot spot areas appeared to be more in the economically developed areas, such as cities and townships. The cluster of spatial-temporal distribution of influenza A (HlNl) pandemic was most likely appearing in Liuyang city (RR=22.70,P<0.01). The secondary cluster would include districts as Yuelu (RR=6A9,P< 0.01) , Yuhua (RR=81.63, P<0.01). Xingsha township appeared as the center in the Changsha county (RR=2.90, P<0.01) while townships as Yutangping (RR=19.31, P<0.01) , Chengjiao (RR=73.14,P<0.01) and Longtian appeared as the center in the west of Ningxiang county (RR= 14.43,P<0.01) and Wushan as the center in the Wangcheng county (RR= 13.84,P<0.01). As time went on, the epidemic moved towards the eastern and more developed regions. Regarding factor analysis, population, the amount of students, geographic relationship and business activities etc. appeared to be the key elements influencing the transmission of influenza A (H1N1) pandemic. At the beginning of the epidemic, population density served as the main factor (r=0.477, P<0.05) but during the initial and fast growing stages, it was replaced by the size of students to serve as the important indicator (r=0.831, P<0.01; r=0.518, P<0.01). However, during the peak of the epidemics, the business activities played an important role (r=-0.676, P<0.01). Conclusion Groups under high risk and districts with high incidence rates were shifting, along with the temporal process of influenza A(H1N1) pandemic, suggesting that the protection measures need to be adjusted, according to the significance of influencing factors at different stages.

Objective To detect the resistance index and esterase activity of each generation of DDVP-resistant Culex mosquitoes and analyze the relationship between insecticide resistance and esterase. Methods WHO bioassay and micro-plate measurement were used for the detection. Results The resistance index increased to 12.17 after 43 generations' insecticide selection compared to 1.00 as sensitive isolate. The nonspecific esterase(NSE) activity of the mosquitoes became strengthened with the extension of the generations, and the individual frequency of those with OD values no less than 0.9 increased gradually, consistent basically to the bioassay. The AChE average inhibition rate decreased with the extended generation and increased resistance, and the individual frequency of those with inhibition rate less than 30% became strengthened with the extension of generations, showing a positive correlation. Conclusion The activity of NSE and AChE shows a correlation with DDVP resistance.

Communicable Disease Control ; Communicable Diseases ; Forecasting ; Models, Statistical

OBJECTIVETo realize the influence of climatic changes on the transmission of hemorrhagic fever with renal syndrome (HFRS), and to explore the adoption of climatic factors in warning HFRS.

METHODSA total of 2171 cases of HFRS and the synchronous climatic data in Changsha from 2000 to 2009 were collected to a climate-based forecasting model for HFRS transmission. The Cochran-Armitage trend test was employed to explore the variation trend of the annual incidence of HFRS. Cross-correlations analysis was then adopted to assess the time-lag period between the climatic factors, including monthly average temperature, relative humidity, rainfall and Multivariate Elño-Southern Oscillation Index (MEI) and the monthly HFRS cases. Finally the time-series Poisson regression model was constructed to analyze the influence of different climatic factors on the HFRS transmission.

RESULTSThe annual incidence of HFRS in Changsha between 2000 - 2009 was 13.09/100 000 (755 cases), 9.92/100 000 (578 cases), 5.02/100 000 (294 cases), 2.55/100 000 (150 cases), 1.13/100 000 (67 cases), 1.16/100 000 (70 cases), 0.95/100 000 (58 cases), 1.40/100 000 (87 cases), 0.75/100 000 (47 cases) and 1.02/100 000 (65 cases), respectively. The incidence showed a decline during these years (Z = -5.78, P < 0.01). The results of Poisson regression model indicated that the monthly average temperature (18.00°C, r = 0.26, P < 0.01, 1-month lag period; IRR = 1.02, 95%CI: 1.00 - 1.03, P < 0.01), relative humidity (75.50%, r = 0.62, P < 0.01, 3-month lag period; IRR = 1.03, 95%CI: 1.02 - 1.04, P < 0.01), rainfall (112.40 mm, r = 0.25, P < 0.01, 6-month lag period; IRR = 1.01, 95CI: 1.01 - 1.02, P = 0.02), and MEI (r = 0.31, P < 0.01, 3-month lag period; IRR = 0.77, 95CI: 0.67 - 0.88, P < 0.01) were closely associated with monthly HFRS cases (18.10 cases).

CONCLUSIONClimate factors significantly influence the incidence of HFRS. If the influence of variable-autocorrelation, seasonality, and long-term trend were controlled, the accuracy of forecasting by the time-series Poisson regression model in Changsha would be comparatively high, and we could forecast the incidence of HFRS in advance.

China ; epidemiology ; Climate Change ; Forecasting ; Hemorrhagic Fever with Renal Syndrome ; epidemiology ; transmission ; Humans ; Humidity ; Incidence ; Models, Theoretical ; Seasons ; Temperature

OBJECTIVETrace and toxic elements have great influences on the fetus growth during the pregnancy. The status of Pb, As, Cd, Mn and Zn in maternal and umbilical cord blood and influence factors were analyzed.

METHODSFrom September 2006 to April 2007, 130 pairs of maternal blood and cord blood in total were collected at the time of spontaneous delivery or cesarean section. At the same time, the development of newborn was measured immediately. The concentrations of elements were determined by inductively coupled plasma mass spectrometry, the relationship of these elements between maternal and cord blood were also analyzed.

RESULTSThe median (microg/L) concentration of blood Pb, As, Cd, Mn and Zn in maternal blood were 64.32, 3.81, 0.84, 54.26 and 6312.50. And the median (microg/L) of those elements in cord blood were 35.72, 2.84, 0.32, 78.99 and 2250. The levels of Cd (r=0.341, P=0.000) and As (r=0.552, P=0.000) in maternal blood were positively correlated with the elements in the cord blood. From the questionnaire we conclude that the occupational hazardous factors and room decorated were the risk factors for the blood As and Zn levels. After multilinear regression analysis we also found mother weight, occupational hazardous factors and mother systolic pressure might affect the levels of blood Mn, Zn, As and Cd.

CONCLUSIONSThe levels of these elements were affected by environmental and maternal factors. In this study, although the levels of all heavy metals in pregnant women were below those considered hazardous, however, they were still higher than those in the developed countries. The effects of heavy metals of maternal exposure on developing fetuses should deserve attention further.

Adult ; Arsenic ; blood ; Cadmium ; blood ; Environmental Exposure ; Female ; Fetal Blood ; chemistry ; Humans ; Infant, Newborn ; Lead ; blood ; Male ; Manganese ; blood ; Maternal Exposure ; Pregnancy ; Zinc ; blood

OBJECTIVETo analyze the periodicity of pandemic influenza A (H1N1) in Changsha in year 2009 and its correlation with sensitive climatic factors.

METHODSThe information of 5439 cases of influenza A (H1N1) and synchronous meteorological data during the period between May 22th and December 31st in year 2009 (223 days in total) in Changsha city were collected. The classification and regression tree (CART) was employed to screen the sensitive climatic factors on influenza A (H1N1); meanwhile, cross wavelet transform and wavelet coherence analysis were applied to assess and compare the periodicity of the pandemic disease and its association with the time-lag phase features of the sensitive climatic factors.

RESULTSThe results of CART indicated that the daily minimum temperature and daily absolute humidity were the sensitive climatic factors for the popularity of influenza A (H1N1) in Changsha. The peak of the incidence of influenza A (H1N1) was in the period between October and December (Median (M) = 44.00 cases per day), simultaneously the daily minimum temperature (M = 13°C) and daily absolute humidity (M = 6.69 g/m(3)) were relatively low. The results of wavelet analysis demonstrated that a period of 16 days was found in the epidemic threshold in Changsha, while the daily minimum temperature and daily absolute humidity were the relatively sensitive climatic factors. The number of daily reported patients was statistically relevant to the daily minimum temperature and daily absolute humidity. The frequency domain was mostly in the period of (16 ± 2) days. In the initial stage of the disease (from August 9th and September 8th), a 6-day lag was found between the incidence and the daily minimum temperature. In the peak period of the disease, the daily minimum temperature and daily absolute humidity were negatively relevant to the incidence of the disease.

CONCLUSIONIn the pandemic period, the incidence of influenza A (H1N1) showed periodic features; and the sensitive climatic factors did have a "driving effect" on the incidence of influenza A (H1N1).

China ; epidemiology ; Climate ; Humans ; Influenza A Virus, H1N1 Subtype ; Influenza, Human ; epidemiology ; virology ; Regression Analysis ; Risk Factors ; Seasons ; Temperature