一起农村小学甲型H3N2流感暴发流行的调查分析

目的了解甲型H3N2流感暴发流行特征,为制定预防措施提供依据。方法对和温村小学239名学生流感发病及流感疫苗接种情况进行调查,对发病者逐一个案调查登记,采集患者咽拭子标本送百色市疾病预防控制中心实验室检测确诊。结果该校学生流感发病33例,发病率为13.81%,学前班及1~6年级共7个班均有病例发生,发病班级为100%。发病者中,男性18例,女性15例,男女性别比为1.2∶1,男女发病率分别为14.52%(18/124)、13.04%(15/115),(χ2=0.11,P0.05),男女发病率差异无统计学意义。患者咽拭子标本5人份,经实验室检测甲型H3N2流感病毒核酸阳性率为100%。结论该校学生无流感疫苗免疫接种史,易感人群积累,是本次甲型H3N2流感暴发流行的根本原因。应在每年秋冬流感流行季节前一个月,加强中小学校学生流感疫苗接种,提高易感人群免疫力,防止甲型H3N2流感扩散蔓延。     

Perception of canine rabies among pupils under 15 years in Kwara State,North Central Nigeria

Rabies is an endemic, highly fatal, and vaccine-preventable disease with severe socio-economic implications. Most (99%) human rabies cases are transmitted through dog bites. Children under 15 years account for 40% of all dog bite victims and 35–50% of all rabies deaths. Rabies awareness among this vulnerable group is critical to rabies prevention. However, there is a paucity of data on rabies awareness among pupils under 15. Hence, this study assessed the awareness and attitude of pupils under 15 years towards canine rabies in Kwara state in Nigeria. The study was conducted as a cross-sectional survey of 1,388 pupils across the state using a structured questionnaire that was administered as a one-on-one interview using the Open Data Kit on Android phones in December 2019. Of the 1388 pupils included in this study, only 21.7% (n = 301) of them were aware of rabies. The mean rabies score was 1.7±0.8 and only 29.2% (n = 88/301) of the pupils had adequate knowledge of canine rabies. The dog ownership rate was 18.7% (n = 259) with an average of 1.93 dogs per household. Approximately 5% (n = 66) of the pupils have been previously bitten by a dog. One-third of the dog bite victims (35%, n = 23/66) were managed and treated at home and only 12% (n = 8/66) were treated in a health facility. The result of the multivariable logistic regression showed that students aged between 13–15 years were more likely (OR: 1.93; 95% CI: 0.72–3.01; p < 0.001) to have adequate knowledge of rabies than the younger pupils. Similarly, pupils that have dogs in their households (OR: 2.09; 95%CI: 1.49–2.75; p < 0.001) and those that reside in Kwara South (OR:1.78 95% CI:1.29, 2.44; p < 0.001) were more likely to be aware and have adequate knowledge of canine rabies respectively. Finally, Pupils from non-dog-owning households were more likely (OR:2.2; 95% CI: 1.45, 4.42; p < 0.001) to have been bitten by dogs than those from dog-owning households. The awareness and attitude of pupils under 15 to canine rabies was poor. We advocate the introduction of rabies lessons into the school curriculum in Kwara State to reduce the incidence of dog bites and prevent dog-mediated human rabies.     

我国甜菜夜蛾大尺度暴发频度与广域温度和广域降雨量关系的预测模型

甜菜夜蛾Spodoptera exigua (Hübner)是我国多种农作物上的重要害虫, 在我国许多地区频繁暴发成灾。为探索甜菜夜蛾种群动态规律并建立种群数量发生趋势预测模型, 作者应用时间序列分析和逐步回归分析方法研究了我国广域（较大范围）温度和广域降雨量变化趋势对我国广域甜菜夜蛾年暴发频度的影响规律。结果表明: 甜菜夜蛾发生的长期趋势和年间波动状况均与广域温度和广域降雨量具有复杂的影响关系。在1979-2008年间, 我国甜菜夜蛾暴发频度呈现出波浪式上升趋势, 其暴发指数平均年递增率为0.076, 而我国广域温度（以27个省市级气象台数据统计为例）在1990-2008年间的平均年递升率为0.039℃, 即我国甜菜夜蛾暴发频度上升趋势与我国广域温度升高趋势同向而行。作者从52个因素（当年和上年1-12月各月及全年日均温和月均降雨量）中筛选出了具有显著回归影响（P<0.05或0.01）的10个因素进入回归模型, 初步找出了能够预测广域甜菜夜蛾暴发趋势指数的温度与降雨量或其组合因素, 并使其模型达到99%以上的历史符合率和预测准确度。作者认为, 广域温、 雨因素与广域甜菜夜蛾暴发趋势指数的这种密切相关性, 不是偶然的巧合, 而是必然的环境（温度和降雨量）作用于生物（甜菜夜蛾）的因果关系。     

Cognitive achievements in identification skills

Species identification tasks are generally accepted as fundamental aspects of biodiversity education. Our educational training unit, therefore, focused on identification skills by introducing stuffed specimens in combination with identification books and preparation booklets.We limited the number of bird species to six. 492 secondary school pupils (163 from 8th grade [high stratification level] and 329 from 9th grade [medium stratification level]) participated in the study. Instruction-1 pupils received a hands-on lesson about the natural history of six bird species, while Instruction-2 pupils were taught in a conventional teacher-centred manner. Pupils from the hands-on classes achieved significantly better grades in two follow-up tests. The measure of well-being was significantly enhanced by the teaching technique, while interest, anxiety and boredom were not affected. Additionally, pupils appreciated the opportunity of self-regulation. In general, a shift from the unspecific to the specific was observed: for instance, from duck and gull to mallard and black-headed gull. A reduction in the number of species presented to pupils within a lesson seems to enhance learning and retention effects.     

Reform of the school system as an anthropological problem--an example from the history education

The article is a longitudinal review of experimental research of high didactic systems effects in history teaching over the last 30 years. The aims of research are to evaluate: 1. position of adolescent, especially neurotic pupils in the teaching process; 2. possibilities to enhance the level of restructured matter (historical anthropology) in programmed and problem-solving teaching; 3. influence on the anxiety, attitudes and success of pupils with changes in the teaching process. Authors conclude, that the teaching process can influence the emotional state of the neurotic pupil. Higher didactic systems in a short time can influence the enhanced level of knowledge in relation to the traditional teaching systems. In the new systems, the attitudes of the pupils towards the teaching can change positively. Experiments carried out point to the possibility of changes of national identity and the necessity of an anthropological approach to reform the educational system.     

Uterine involvement in guineapig salmonellosis

Of 334 mature breeding guineapigs, 53 (15.9%) died in a disease outbreak involving Salmonella typhimurium serotypes 1, 4, 5 and 12 : i : 1,2. The uterus was consistently involved. Nine other Salmonella-free mature female guineapigs when inoculated with a pure isolate from the outbreak, using the subcutaneous, intramuscular or per os route, succumbed to salmonellosis, reproducing signs and lesions observed during the outbreak. Abortion was not recorded during the outbreak despite many pregnant sows being affected. The isolate was sensitive to gentamicin, tetracycline, ampicillin and cefuroxime but resistant to co-trimoxazole, erythromycin and penicillin.     

Giardia cysts in sewage influent in Bergen, Norway 15-23 months after an extensive waterborne outbreak of giardiasis

Aims: In autumn/winter 2004, a large outbreak of waterborne giardiasis occurred in Bergen, Norway. Over 1 year later, the concentrations and genotypes of Giardia cysts occurring in sewage influent were studied to investigate the impact of the outbreak event on Giardia infections in the community. Methods and Results: Sewage influent samples from four sewage treatment works (STW) serving Bergen were analysed for Giardia cysts on four occasions between 15 and 23 months after the outbreak. Cysts genotypes were investigated at one to three genes. Data from influent analysis from one of the STW before the outbreak, and from patient faecal samples analysed during the outbreak, provided baseline comparative data. Relatively high concentrations of Giardia cysts of diverse genotypes, both from Assemblages A and B, were detected at all STW. Conclusions: Comparison of data suggests that although Giardia cyst concentrations in sewage influent returned to pre‐outbreak levels within 18 months after the outbreak peak, the genetic composition of the isolates remained significantly influenced by the Assemblage B isolate associated with the outbreak. Significance and Impact of the Study: Genotypes associated with an extensive outbreak of giardiasis continued to occur in Giardia infections in Bergen’s population many months after the outbreak was considered to be over.     

某起新型冠状病毒肺炎聚集性疫情的流行病学分析

目的:通过分析一起新型冠状病毒肺炎(coronavirus disease 2019,COVID-19)聚集性疫情病例的流行病学特征,为疫情防控提供科学参考依据。方法:以新型冠状病毒肺炎防控技术方案的相关内容为依据,对一起聚集性疫情病例发病、就诊、接触方式及代际传播等进行描述性流行病学分析。结果:该起聚集性疫情涉及6例确诊病例,波及人数为98人,感染率为5.10%(5/98),其中男性3例、女性3例,年龄25~72岁,临床表现为发热4例、乏力2例、干咳2例、咳痰1例、呼吸困难1例、呕吐1例、腹泻1例、肌肉酸痛1例,临床表现严重程度分为普通型5例,重型1例,从发病到诊断平均时间间隔5.3 d,从诊断到报告平均时间间隔1.2 h,本起疫情暴露场所为家庭,以近距离飞沫或密切接触为接触方式传播的,潜伏期中位数7 d(6 d~12 d)。指示病例为男性、51岁,二代病例共4例,三代病例1例。结论:本起聚集性疫情以家庭为暴露场所,且以近距离飞沫或密切接触为接触方式传播,通过加强疫情预警、监测,对病例早发现、早报告、早隔离、早治疗以及对其密切接触者的严格筛查和管理,达到有效防控疫情发生、发展及防止蔓延。     

Extinction thresholds in deterministic and stochastic epidemic models

The basic reproduction number, ?(0), one of the most well-known thresholds in deterministic epidemic theory, predicts a disease outbreak if ?(0)>1. In stochastic epidemic theory, there are also thresholds that predict a major outbreak. In the case of a single infectious group, if ?(0)>1 and i infectious individuals are introduced into a susceptible population, then the probability of a major outbreak is approximately 1-(1/?(0))( i ). With multiple infectious groups from which the disease could emerge, this result no longer holds. Stochastic thresholds for multiple groups depend on the number of individuals within each group, i ( j ), j=1, …, n, and on the probability of disease extinction for each group, q ( j ). It follows from multitype branching processes that the probability of a major outbreak is approximately [Formula: see text]. In this investigation, we summarize some of the deterministic and stochastic threshold theory, illustrate how to calculate the stochastic thresholds, and derive some new relationships between the deterministic and stochastic thresholds.     

Opinion building on a socio-scientific issue: the case of genetically modified plants

This paper presents results from a study with the following research questions: (a) are pupils' opinions on genetically modified organisms (GMOs) influenced by biology teaching; and (b) what is important for the opinion pupils hold and how does knowledge work together with other parameters such as values? 64 pupils in an upper secondary school answered questionnaires, in which they expressed opinions and gave arguments on applications of GMOs, before and after biology courses. The pupils' knowledge of genetics and GMOs was also investigated. Eleven pupils were then in-terviewed to examine their reasoning in more depth. More pupils were positive about genetically modified tomatoes after the courses. Males were more positive than females. No correlation was found between knowledge of basic genetics and opinion. Most of the pupils could express arguments for and against the applications but they built their personal opinion on different arguments. An important concern was potential risks. Depending on risk judgement and/or how they trusted scientists, the pupils came to different conclusions. Few had any idea of how the different applications are risk assessed or how scientists work. Other important factors for decision-making were the purpose of the application, the time perspective and feelings.     

An Outbreak of Acute Enteritis Due to Campylobacter fetus Subspecies jejuni at a Nursery School in Tokyo

An outbreak of acute enteritis due to Campylobacter fetus subspecies jejuni involving a total of 35 out of 74 children occurred at a nursery school in Tokyo in January 1979 and lasted for 7 days. It was the first case of a community outbreak of the disease to be recognized in Japan. The major symptoms observed in the patients consisted of diarrhea (88%), fever (82%), abdominal pain (39%), and vomiting (6.1%). The rate of isolation of the organism from the patients was 39%. Sera of four patients showed elevated agglutinin titers against the organism ranging from 1 : 80 to 1 : 320. Although it is suggested that the outbreak was caused by a communal lunch or between-meal snacks prepared by and provided at the nursery school, the incriminated food, source and route of contamination could not be pinpointed.     

Detecting early-warning signals for influenza A pandemic based on protein dynamical network biomarkers

The outbreak of influenza A comes from a relatively stable state is a critical phenomenon on epidemic. In this paper, influenza A varying from different states is studied in the method of dynamical network biomarkers (DNB). Through studying DNB of influenza A virus protein, we can detect the warning signals of outbreak for influenza A and obtain a composite index. The composite index varies along with the state of pandemic influenza, which gives a clue showing the turn point of outbreak. The low value (<1) steady state of the composite index means influenza A is normally in the relatively steady stage. Meanwhile, if the composite index of a certain year increases by more than 0.8 relative to the previous year and it is less than 1 and it increases sharply and reaches a peak being larger than 1 in next year, it means the year is normal in the critical state before outbreak and the next year is normally in the outbreak state. Therefore, we can predict the outbreak of influenza A and identify the critical state before influenza A outbreak or outbreak state by observing the variation of index value.     

儿童重症监护病房医院感染暴发白色念珠菌血流感染4例分析

摘要 目的：探讨儿童重症监护病房白色念珠菌血流感染暴发的临床表现、危险因素、控制措施等,为预防和控制院内白色念珠菌血流感染暴发提供科学依据。方法：以2018年7月我院儿童重症监护病房发生的4例白色念珠菌血流感染暴发患儿为研究对象,分析患儿临床情况、临床特征、危险因素、暴发原因以及采取的预防控制措施。结果：4例医院感染暴发白色念珠菌血流感染患儿均存在基础疾病、有机械通气史、存在中心静脉或动脉置管、静脉或动脉置管前后均使用碘伏消毒、曾使用广谱抗生素、输血制品,白色念珠菌血流感染后最突出的临床表现均是发热。药敏方面,医院感染暴发的4例白色念珠菌感染患儿对唑类及5-氟胞嘧啶均耐药,但对两性霉素B均敏感。经拔除血管置管、减少或者避免广谱抗菌药的应用,根据药敏使用卡泊芬净及两性霉素B抗真菌等积极治疗,1例患儿放弃治疗后死亡,3例患儿顺利出院。通过Fisher确切概率法分析可知,留置中心静脉或动脉置管是儿童重症监护病房发生医院感染暴发白色念珠菌血流感染的危险因素（P<0.05）。结论：留置中心静脉或动脉置管是儿童重症监护病房发生医院感染暴发白色念珠菌血流感染的危险因素,医院感染暴发白色念珠菌血流感染患儿最突出的临床表现是发热,唑类及5-氟胞嘧啶耐药的患儿使用卡泊芬净及两性霉素B可能获得较好的治疗效果。     

Evaluation of Inapparent Dengue Infections During an Outbreak in Southern China

Few studies evaluating inapparent dengue virus (DENV) infections have been conducted in China. In 2013, a large outbreak of DENV occurred in the city of Zhongshan, located in Southern China, which provided an opportunity to assess the clinical spectrum of disease. During the outbreak, an investigation of 887 index case contacts was conducted to evaluate inapparent and symptomatic DENV infections. Post-outbreak, an additional 815 subjects from 4 towns with, and 350 subjects from 2 towns without reported autochthonous DENV transmission, as determined by clinical diagnosis, were evaluated for serological evidence of dengue IgG antibodies. Between July and November 2013, there were 19 imported and 809 autochthonous dengue cases reported in Zhongshan. Of 887 case contacts enrolled during the outbreak, 13 (1.5%) exhibited symptomatic DENV infection, while 28 (3.2%) were inapparent. The overall I:S ratio was 2.2:1 (95% CI: 1.1-4.2:1). Post-outbreak serological data showed that the proportion of DENV IgG antibody detection from the 4 towns with and the 2 towns without reported DENV transmission was 2.7% (95% CI: 1.6%-3.8%) and 0.6% (95% CI: 0-1.4%), respectively. The I:S ratio in the 3 towns where clinical dengue cases were predominately typed as DENV-1 was 11.0:1 (95% CI: 3.7-∞:1). The ratio in the town where DENV-3 was predominately typed was 1.0:1 (95% CI: 0.5-∞:1). In this cross-sectional study, data suggests a high I:S ratio during a documented outbreak in Zhongshan, Southern China. These results have important implications for dengue control, implying that inapparent cases might influence DENV transmission more than previously thought.     

Factors associated to duration of hepatitis a outbreaks: implications for control

Even though hepatitis A mass vaccination effectiveness is high, outbreaks continue to occur. The aim of this study was to investigate the association between duration and characteristics of hepatitis A outbreaks. Hepatitis A (HA) outbreaks reported between 1991 and 2007 were studied. An outbreak was defined as ≥2 epidemiologically-linked cases with ≥1 case laboratory-confirmed by detection of HA immunoglobulin M (IgM) antibodies. Relationships between explanatory variables and outbreak duration were assessed by logistic regression. During the study period, 268 outbreaks (rate 2.45 per million persons-year) and 1396 cases (rate 1.28 per 10⁵ persons-year) were reported. Factors associated with shorter duration were time to intervention (OR = 0.96; 95% CI: 0.94–0.98) and school setting (OR = 0.39; 95% CI: 0.16–0.92). In person-to-person transmission outbreaks only time to intervention was associated with shorter outbreak duration (OR = 0.96; 95% CI: 0.95–0.98). The only variables associated with shorter outbreak duration were early administration of IG or vaccine and a school setting. Timely reporting HA outbreaks was associated with outbreak duration. Making confirmed HA infections statutory reportable for clinical laboratories could diminish outbreak duration.     

Climate change could alter the distribution of mountain pine beetle outbreaks in western Canada

Climate change can markedly impact biology, population ecology, and spatial patterns of eruptive insects due to the direct influence of temperature on insect development and population success. The mountain pine beetle Dendroctonus ponderosae (Coleoptera: Curculionidae), is a landscape‐altering insect that infests forests of North America. Abundant availability of host trees due to altered disturbance regimes has facilitated an unprecedented, landscape‐wide outbreak of this pest in British Columbia and Alberta, Canada, during the past decade. A previous outbreak in the 1980s, in central British Columbia, collapsed due to host depletion and extreme cold weather events. Despite the importance of such extreme weather events and other temperature‐related signals in modulating an outbreak, few landscape‐level models have studied the associations of extreme cold events with outbreak occurrences. We studied the individual associations of several biologically‐relevant cold temperature variables, and other temperature/degree‐day terms, with outbreak occurrences in a spatial‐temporal logistic regression model using data from the current outbreak. Timing, frequency, and duration of cold snaps had a severe negative association with occurrence of an outbreak in a given area. Large drops in temperature (>10°C) or extreme winter minimum temperatures reduced the outbreak probability. We then used the model to apply eight different climate change scenarios to the peak year of the current outbreak. Our scenarios involved combinations of increasing annual temperature and different variances about this trend. Our goal was to examine how spatial outbreak pattern would have changed in the face of changing thermal regime if the underlying outbreak behaviour remained consistent. We demonstrate that increases in mean temperature by 1°C to 4°C profoundly increased the risk of outbreaks with effects first being manifested at higher elevations and then at increasing latitudes. However, increasing the variance associated with a mean temperature increase did not change the overall trend in outbreak potential.     

Impact of silkmoth outbreak on taiga wildfires

We provide a quantitative analysis of postoutbreak wildfire frequency within the confluence of the Yenisei and Angara rivers affected by the Siberian Silkmoth (Dendrolimus sibiricus Tschetv.). A catastrophic outbreak was observed in 1993–1996. It expanded to about 1 million ha and caused stand mortality on an area of about 460000 ha. For the outbreak area, the fire frequency was about 7 times higher when compared to the reference area; on the burned area, it was 20 times higher. The peak of fire activity within outbreak areas occurs in May–June, while that for undamaged coniferous stands is in July. The number of fires is correlated with the mean monthly air temperature (r = 0.65) of June. The area of fires displays a negative correlation with moisture conditions: precipitation (r =–0.53), drought index (SPEI: r =–0.57), and ground-cover moisture content (r =–0.57). Extensive fires prevail within outbreak areas (S > 1000 ha), while within the control there is a smaller area of fires. Multiple (reoccurring) wildfires are typical for pest outbreak areas. The area of these fires is related to their reoccurrence by logarithmic dependence (17% of the territory twice burned by forests fires, 5% on that burned three times, and 0.5% on that burned four times). Wildfires in the outbreak areas surpress the initial forest recovery by destroying the regeneration of conifers: 20 years after the outbreak, >90% of disturbed areas are occupied by grass–bush and small-leaved cenoses.     

Biological Sciences Curriculum Study

In order to name an animal they see, children use their existing mental models to provide the animal with a name. In this study, pupils of a range of ages (4, 8, 11, and 14 years old) were presented with preserved specimens of six different animals and asked a series of questions about them. The results indicate that pupils of all ages mainly recognize and use anatomical features when naming the animals and explaining why they are what they are. However, older pupils are more likely to also use behavioural and habitat attributes. For both girls and boys, the home and direct observation are more important as sources of knowledge than school or books, although books seem more important for boys than for girls. As pupils age, their reasons for grouping animals become more complicated: in addition to relying on shared anatomical features, they begin to show evidence of an embedded taxonomic knowledge, knowing, for instance, what a mammal is and using this knowledge to group animals.     

Nonhomogeneous birth and death models for epidemic outbreak data

In this paper, generalized nonlinear models are proposed in order to incorporate the following considerations in modeling an epidemic disease outbreak statistically. (1) The dependence of the data is handled with a nonhomogeneous death or a nonhomogeneous birth process. (2) The first stage of the outbreak is described with an epidemic susceptibles-infectives-removed (SIR) model. Soon the control measures taken will dominate the process. These measures are in addition to the natural epidemic removal process. The prevalence is related to the censored infection times in such a way that the distribution function and thus the survival function satisfy approximately the first equation of the SIR model. This leads in a natural way to the Burr family of distributions. (3) The nonhomogeneous birth process handles the fact that in practice, with some delay, infecteds are registered, but not susceptibles. (4) Finally, the ending of the epidemic caused by the measures taken is incorporated through a modification of the survival function with a final-size parameter, in the same way as is done in long-term survival models. These models are applied to three outbreaks: The Dutch classical swine fever outbreak from 1997 to 1998, the foot- and-mouth disease outbreak in Great Britain from 2001, and the Dutch avian influenza (H7N7) outbreak from 2003.     

Formative fieldwork for the younger pupil

In the early days of the FSC, younger pupils comprised only about 4% of visitors to the Centres; this proportion fell to around 1% in the mid 1970s but has risen dramatically (to 16% in 1986) during the present decade. During 1986, the introduction of GCSE has brought a further factor into play and the F'SC's junior category now embraces the range from 6-year-olds to GCSE pupils. At all levels, courses are carefully designed in consultation with school staff to enable pupils to gain the maximum benefit from their visit. While there is always a carefully-structured basis to a course, the approach to a topic is as heuristic as possible and child-centred learning is considered critically important. In GCSE courses, care is taken to link content to both the National Criteria of the Secondary Examination Council and the more detailed requirements of the particular syllabus being followed.