Managing the risk of a COVID-19 outbreak from border arrivals

In an attempt to maintain the elimination of COVID-19 in New Zealand, all international arrivals are required to spend 14 days in government-managed quarantine and to return a negative test result before being released. We model the testing, isolation and transmission of COVID-19 within quarantine facilities to estimate the risk of community outbreaks being seeded at the border. We use a simple branching process model for COVID-19 transmission that includes a time-dependent probability of a false-negative test result. We show that the combination of 14-day quarantine with two tests is highly effective in preventing an infectious case entering the community, provided there is no transmission within quarantine facilities. Shorter quarantine periods, or reliance on testing only with no quarantine, substantially increases the risk of an infectious case being released. We calculate the fraction of cases detected in the second week of their two-week stay and show that this may be a useful indicator of the likelihood of transmission occurring within quarantine facilities. Frontline staff working at the border risk exposure to infected individuals and this has the potential to lead to a community outbreak. We use the model to test surveillance strategies and evaluate the likely size of the outbreak at the time it is first detected. We conclude with some recommendations for managing the risk of potential future outbreaks originating from the border.     

Identification of Human Adenovirus in Respiratory Samples with Luminex Respiratory Virus Panel Fast V2 Assay and Real-Time Polymerase Chain Reaction

In order to compare the last version of the Respiratory Virus Panel (RVP) Fast assay for human Adenovirus (hAdv) detection with a specific real-time polymerase chain reaction (qPCR), which is considered the gold standard for hAdv detection, nasopharyngeal samples collected from 309 children (age range, four months to eight years) with respiratory tract infection were tested using the RVP Fast v2 assay (Luminex Molecular Diagnostics, Inc., Toronto, ON, Canada) and a specific TaqMan qPCR to identify hAdv DNA. The RVP Fast v2 assay detected 30/61 (49.2%) hAdv infections that had been identified by real-time qPCR, demonstrating a significantly lower detection rate (p < 0.001). The sensitivity of the RVP Fast v2 assay in comparison to qPCR was lower in younger children (42.9% vs. 57.7%; Cohen’s kappa coefficient, 0.53); in samples with co-infections (40.0% vs. 56.7%; Cohen’s kappa coefficient, 0.52); and in samples with hAdv type C (45.9% vs. 57.1%; Cohen’s kappa coefficient, 0.60). Samples with lower viral loads were associated with a significantly lower sensitivity of the RVP Fast v2 assay (35.1% vs. 68.2%, p = 0.01; Cohen’s kappa coefficients, 0.49). The RVP Fast v2 assay has important limitations for the detection of hAdv and cannot be used to evaluate whether hAdvs are the main etiologic agent responsible for an outbreak or when epidemiological studies are performed.     

Predictive factors of psychological disorder development during recovery following SARS outbreak.

Objective: To investigate strategies for broad mass isolation during outbreaks of infectious diseases. Design: A survey using a self-administered questionnaire was conducted on 300 printing company workers in Beijing, China, which was under mass isolation following the 2003 SARS outbreak, in the 7-8 months after the isolation was lifted. Main Outcome Measures: Individuals with psychological disorders were classified on the basis of scores on the 30-item General Health Questionnaire during the recovery period. Psychological disorders were observed in 49 of 187 respondents (26.2%; 95% CI = 20.2, 32.7). Results: The predicting factor with the highest correlation was income reduction, with an odds ratio of 25.0. Other items obtained were gender, range of activities, eating restrictions, restrictions in going out, disinfection of clothing, and infection control, with odds ratios of 3.2, 5.5, 3.9, 3.2, 0.2, and 0.1, respectively, and the contribution ratio was 87.7%. Conclusion: Securing income is suggested to be important in future strategies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

How necessary is a fast testkit for mitigation of pandemic flu?

It is widely feared that a novel, highly pathogenic, human transmissible influenza virus may evolve that could cause the next global pandemic. Mitigating the spread of such an influenza pandemic would require not only the timely administration of antiviral drugs to those infected, but also the implementation of suitable intervention policies for stunting the spread of the virus. Towards this end, mathematical modelling and simulation studies are crucial as they allow us to evaluate the predicted effectiveness of the various intervention policies before enforcing them. Diagnosis plays a vital role in the overall pandemic management framework by detecting and distinguishing the pathogenic strain from the less threatening seasonal strains and other influenza-like illnesses. This allows treatment and intervention to be deployed effectively, given limited antiviral supplies and other resources. However, the time required to design a fast and accurate testkit for novel strains may limit the role of diagnosis. Herein, we aim to investigate the cost and effectiveness of different diagnostic methods using a stochastic agent-based city-scale model, and then address the issue of whether conventional testing approaches, when used with appropriate intervention policies, can be as effective as fast testkits in containing a pandemic outbreak. We found that for mitigation purposes, fast and accurate testkits are not necessary as long as sufficient medication is given, and are generally recommended only when used with extensive contact tracing and prophylaxis. Additionally, in the event of insufficient medication and fast testkits, the use of slower, conventional testkits together with proper isolation policies while waiting for the diagnostic results can be an equally effective substitute.     

新冠肺炎疫情下高校信息化服务工作的探索与实践——以吉林化工学院为例

高校的信息化建设已经成为衡量学校办学水平的一项重要标准,也是高校服务工作重点建设部分.同时,加强信息化建设,有利于推动学校发展,提升高校的办公条件,促进学校教学工作的改进与延伸.本文是吉林化工学院在新冠肺炎情况下,对学校信息化服务工作进行的一系列应对探索与实践工作,介绍如何开展全校在线办公、线上教学.也对在爆发传染性突发公共卫生事件后,如何有效的开展各项工作,提供了一定的参考示范。     

Automatic detection of Salmonella enterica in sprout irrigation water using a nucleic acid sensor

A nucleic acid sensor capable of automated sample and reagent loading, real-time PCR, automated detection, and sample line cleaning was tested. Real-time PCR reactions were performed with Salmonella enterica in autoclaved and spent alfalfa sprout irrigation water. S. enterica boiled cells were detected over a range of approximately 10⁴ to 10⁸ CFU/reaction (rxn). It was possible to generate enough PCR product to visualize a band on a gel at the expected size over approximately five orders of magnitude from 3.2 × 10³ to 10⁸ CFU/rxn. Automated detection experiments yielded correct identification of 9/9 positive control reactions over a range of 10⁴ to 10⁸ CFU/rxn, correctly identified a negative control reaction, and a sample of 3.2 × 10³ CFU/rxn was incorrectly identified as negative. Primer dimers were not seen in positive or negative control reactions with sprout irrigation water, suggesting that it may be possible to improve the detection limit simply by increasing the number of thermal cycles or by lowering the annealing temperature. The system required no interpretation of real-time PCR data by the operator. The entire process of loading, running the PCR, automated data interpretation, and sample line cleaning was completed in under 2 h and 20 min, significantly faster than it would take to ship a sample and have it tested by an independent laboratory.     

自然崩落法诱发井下泥石流降雨临界阈值试验

诱发井下泥石流灾害的降雨阈值是矿山井下泥石流防控重要参数。为获得普朗铜矿诱发井下泥石流的降雨临界阈值,以室内试验为研究方法,开展矿区不同降雨强度工况下诱发井下泥石流的降雨量阈值及暴发时间研究。结果表明：当雨强为0.563 mL/min时发生破坏性较大井下泥石流概率较大,当雨强为0.293 mL/min时诱发井下泥石流概率较小,当雨强为0.186 mL/min时则不易形成井下泥石流;降雨强度0.293 mL/min是井下泥石流发生的极限临界状态,也即是诱发井下泥石流的降雨阈值;降雨强度0.563 mL/min时,3#、4#和2#不同放矿口诱发井下泥石流的暴发时间分别为240、260和220 min;降雨强度0.293 mL/min时,3#、4#和2#放矿口诱发井下泥石流的暴发时间分别为180、200和220 min;最后基于水量总量原理验证了试验确定降雨临界阈值的科学性和合理性。研究成果为普朗铜矿及类似矿山井下泥石流的预防和管控提供重要的科学理论依据。     

2015—2019年云南省家庭食源性疾病暴发事件分析

目的 分析2015—2019年云南省家庭食源性疾病暴发事件的流行病学特点,为制定家庭食源性疾病防控措施提供参考。方法 对2015—2019年云南省食源性疾病暴发监测系统中报告的家庭食源性疾病暴发事件数据进行统计分析。结果 2015—2019年云南省共报告家庭食源性疾病3 159起,发病12 402人,死亡229人,病死率为1.85%(229/12 402)。2015—2019年云南省家庭食源性疾病暴发事件发病数呈上升趋势,发生在6—8月事件数、发病数和死亡数最多。从致病因素和原因食品分析,野生菌引起的事件数、发病数和死亡数最多,其次是乌头类植物。结论 加强野生菌和乌头类植物中毒的防控力度,提高群众预防野生菌和乌头类植物中毒的意识和能力,是有效预防和控制云南省家庭食源性疾病事件发生的重要措施。     

2013年山东省食源性疾病暴发事件 流行病学特征分析

目的分析2013年山东省食源性疾病暴发事件的流行病学特征,为制定食源性疾病预防控制措施提供依据。方法对2013年通过国家食源性疾病暴发报告系统上报的30起食源性疾病暴发事件进行整理分析。结果 2013年共发生食源性疾病暴发事件30起,发病人数654人,死亡2人。食源性疾病暴发事件的主要发病季节是第三季度,全年食源性疾病暴发主要发生在4~10月份,其中以8月份最高;16~60岁人群是暴发事件发生的主要人群;饮食服务单位是发生食源性疾病暴发事件的主要场所,其次是集体食堂;加工不当与交叉污染是引起食源性疾病暴发事件的主要原因:微生物是引起食源性疾病暴发事件发生的主要致病因素,不同致病因素之间导致的罹患率不同(P0.05);引起食源性疾病暴发事件的主要原因食品是混合食品。结论加强对高发季节、高发因素、高发污染环节的监控;加强食源性疾病暴发事件的调查处置;加大防控食源性疾病暴发事件的宣传力度等,是预防和控制食源性疾病暴发事件的有效措施。     

2010—2020年中国大陆金黄色葡萄球菌及其肠毒素引起的食源性疾病暴发事件归因分析

目的 分析我国金黄色葡萄球菌及其肠毒素引起的食源性疾病暴发事件的流行病学特征。方法 收集整理2010—2020年国家食源性疾病暴发监测系统和文献检索的数据,对金黄色葡萄球菌及其肠毒素引起的暴发事件进行归因分析。结果 共纳入2010—2020年食源性疾病暴发事件703起（监测系统694起,文献数据9起）,单维度归因分析发现原因食品中肉类食品最高,占28.3%（199/703）,主要引发环节中因食品存储不当最高,占15.2%（107/703）,主要发生场所中餐饮服务场所最高,占85.2%（599/703）;多维度分析结果显示,华东地区各季节事件发生数均最多。除肉类食品外,我国华东和华南地区主要原因食品还有糕点类食品和米面食品,这两种食品多以存储不当而引发。发生在餐饮服务场所的暴发事件中肉类食品和米面食品主要是由于加工时污染致病因子引发,而糕点类食品主要是由于存储不当引发。结论 由金黄色葡萄球菌及其肠毒素引发的食源性疾病以肉类食品高发,应对餐饮服务场所、食品加工、储存等环节加强监管,降低发病风险。