Epidemiology is a traditional subject mainly based on principles and concepts, and its teaching method needs further improving to meet the requirement of the new trend of education reform. Lecture-based teaching, problem-based teaching, case-based teaching, and internet based teaching, such as flip class, massive open online course and micro-lecture, all have its own unique merits in the practice of epidemiology teaching. So the combination of traditional teaching and online teaching is the most promising mode. "Rain class" , a mixed mode, is an efficient tool to present the epidemiology case more actually in class. Thus, teaching design and application of "rain class" are worth research.
Computer-Assisted Instruction ; Epidemiology/education* ; Humans ; Internet ; Online Systems ; Research ; Teaching

Objective: To understand the molecular characteristics of hemagglutinin (HA) and neuraminidase (NA) as well as the disease risk of influenza virus A H7N9 in Guizhou province. Methods: RNAs were extracted and sequenced from HA and NA genes of H7N9 virus strains obtained from 18 cases of human infection with H7N9 virus and 6 environmental swabs in Guizhou province during 2014-2017. Then the variation and the genetic evolution of the virus were analyzed by using a series of bioinformatics software package. Results: Homology analysis of HA and NA genes revealed that 2 strains detected during 2014-2015 shared 98.8%-99.2% and 99.2% similarities with vaccine strains A/Shanghai/2/2013 and A/Anhui/1/2013 recommended by WHO, respectively. Two strains detected in 2016 and 14 strains detected in 2017 shared 98.2%-99.3% and 97.6%-98.8% similarities with vaccine strain A/Hunan/02650/2016, respectively. Other 6 stains detected in 2017 shared 99.1%-99.4% and 98.9%-99.3% similarities with strain A/Guangdong/17SF003/2016, respectively. Phylogenetic analysis showed that all the strains were directly evolved in the Yangtze River Delta evolution branch, but they were derived from different small branch. PEVPKRKRTAR↓GLF was found in 6 of 24 strains cleavage site sequences of HA protein, indicating the characteristic of highly pathogenic avian influenza virus. Mutations A134V, G186V and Q226L at the receptor binding sites were found in the HA. All the strains had a stalk deletion of 5 amino acid residue "QISNT" in NA protein, and drug resistance mutation R294K occurred in strain A/Guizhou-Danzhai/18980/2017. In addition, potential glycosylation motifs mutations NCS42NCT were found in the NA of 9 of 24 strains. Conclusions: HA and NA genes of avian influenza A (H7N9) virus showed genetic divergence in Guizhou province during 2014-2017. The mutations of key sites might enhance the virulence of the virus, human beings are more susceptible to it. Hence, the risk of infection is increasing.
Animals ; Base Sequence ; Birds ; China/epidemiology* ; Genome, Viral ; Hemagglutinin Glycoproteins, Influenza Virus/immunology* ; Hemagglutinins/genetics* ; Humans ; Influenza A Virus, H7N9 Subtype/isolation & purification* ; Influenza in Birds ; Influenza, Human/virology* ; Neuraminidase/genetics* ; Phylogeny ; RNA, Viral/genetics* ; Sequence Analysis, DNA

Objective: From the economic point of view, this study was to systematically assess the status quo on lung cancer screening in the world and to provide reference for further research and implementation of the programs, in China. Methods: PubMed, EMbase, The Cochrane Library,CNKI and Wanfang Data were searched to gather papers on studies related to economic evaluation regarding lung cancer screening worldwide, from the inception of studies to June 30(th), 2018. Basic characteristics, methods and main results were extracted. Quality of studies was assessed. Cost were converted to Chinese Yuan under the exchange rates from the World Bank. The ratio of incremental cost-effectiveness ratio (ICER) to local GDP per capita were calculated. Results: A total of 23 studies (only 1 randomized controlled trial) were included and the overall quality was accepted. 22 studies were from the developed countries. Nearly half of the studies (11 studies) took 55 years old as the starting age of the screening program. Smoking history was widely applied for the selection of criteria on target populations (18). Low-dose computed tomography (LDCT) was involved in every study used to evaluate the economic effectiveness. Annual (17) and once-life time (7) screening were more common frequencies. 22 studies reported ICERs for LDCT screening, compared to no screening, of which 17 were less than 3 times local GDP per capita, and were considered as cost-effectiveness, according to the WHO's recommendation. 15 and 7 studies reported ICERs for annual and once-life time screening, of which 12 and 7 studies were in favor the results of their cost-effectiveness, respectively. Additionally, the cost-effectiveness of once-lifetime screening was likely to be superior to the annual screening. Differences of cost-effectiveness among the subgroups, by starting age or by the smoking history, might exist. Conclusions: Based on the studies, evidence from the developed countries demonstrated that LDCT screening programs on lung cancer, implemented among populations selected by age and smoking history, generally appeared more cost-effective. Combined with the local situation of health resource, the findings could provide direction for less developed regions/countries lacking of local evidence. Low frequency of LDCT screening for lung cancer could be adopted when budget was limited. Data on starting ages, smoking history and other important components related to the strategy of screening programs, needs to be precisely evaluated under the situation of local population.
China ; Cost-Benefit Analysis ; Early Detection of Cancer/methods* ; Humans ; Lung Neoplasms/prevention & control* ; Middle Aged ; Quality-Adjusted Life Years ; Randomized Controlled Trials as Topic