2020年1—2月全球主要疫情回顾

本刊对2020年1-2月全球重点传染病疫情(截至2月28日)汇总如下。1中国暴发新型冠状病毒肺炎2019年12月下旬,中国湖北省武汉市出现了不明原因的群发肺炎病例,先期出现的几十例病例与华南海鲜市场有关,患者症状与SARS相似。2020年1月病例数急剧增加,疫情向全国其他省份扩散。中国政府于1月23日对武汉市进行了“封城”,同时全国居民尽最大可能居家隔离,以控制疫情扩散。经过全国上下一致努力,疫情得到明显控制,2月18日全国累计病例数达到峰值74000例(其中湖北省62000例)后,每日新增病例数逐渐下降,大多省份每日新增病例数减少为0,只有武汉市每日新增300~400例,截至2月底,全国累计报告确诊病例约79000例,治愈出院病例约39000例,累计死亡病例2837例。     

Multiannual forecasting of seasonal influenza dynamics reveals climatic and evolutionary drivers

Human influenza occurs annually in most temperate climatic zones of the world, with epidemics peaking in the cold winter months. Considerable debate surrounds the relative role of epidemic dynamics, viral evolution, and climatic drivers in driving year-to-year variability of outbreaks. The ultimate test of understanding is prediction; however, existing influenza models rarely forecast beyond a single year at best. Here, we use a simple epidemiological model to reveal multiannual predictability based on high-quality influenza surveillance data for Israel; the model fit is corroborated by simple metapopulation comparisons within Israel. Successful forecasts are driven by temperature, humidity, antigenic drift, and immunity loss. Essentially, influenza dynamics are a balance between large perturbations following significant antigenic jumps, interspersed with nonlinear epidemic dynamics tuned by climatic forcing.Influenza outbreaks have been documented in the scientific literature in records that extend back to at least 1650 (1), making it an exceptional example of a persisting, recurrent disease. Being a respiratory infection, influenza spreads rapidly from person to person through a population in the form of virus particles airborne as respiratory droplets or aerosols. Depending on the circumstances, influenza typically infects between 10% and 50% of a given population and has become a source of considerable human morbidity and mortality (2). There is much controversy in identifying the seasonal drivers that generate annual influenza epidemics and the processes that give rise to their large variability (3–12). This is an outstanding problem of influenza research today. Using long-term modeling, a recent study (9) gave support to the possibility that absolute humidity is the predominant determinant of influenza seasonality in temperate zones, driving disease transmission and controlling the timing of individual wintertime outbreaks. Another study investigated the physical properties of absolute humidity on influenza virus transmission and influenza virus survival (3). However, a general understanding of the mechanisms underlying influenza seasonal variation remains quite limited (8). Here, we use a simple mathematical model to unravel the interplay between climate and evolution to predict long-term influenza dynamics correctly for the years since June 2010.A requirement for the generation of recurrent epidemics is a sufficient and continuous source of new susceptible individuals arising in the population, enough to fuel each new outbreak (13). In the case of influenza, infected individuals recover with immunity but eventually become susceptible again because of the rapidly evolving nature of the influenza virus (7, 14). Positive selection exerted by the host immune system leads to a continual antigenic drift of the influenza virus’s glycoproteins, particularly the main antigen, hemagglutinin, thus allowing the virus to eventually evade the immune system (15). The process of antigenic drift thereby creates an important renewed source of susceptible individuals. Hence, evolutionary forces are considered tremendously important in shaping complex recurrent patterns of infectious diseases and explain why influenza is regarded as “an invariable disease caused by a variable virus” (1).The changing rate of antigenic drift also has a significant impact on the timing and amplitude of influenza outbreaks (16). Recent studies reveal that the evolution of influenza A H3N2’s main antigen is punctuated in character such that the drift occurs within discrete antigenic clusters (neutral periods), but with jumps to newly arising clusters after irregular periods (17, 18). A significant jump for the A H3N2 lineage last occurred during the 2003–4 season with the appearance of the A/Fujian virus strain coinciding with a sharp influenza outbreak approximately 2 mo earlier than usual, with a normal attack rate. Nevertheless, it is difficult to demonstrate a consistent and conclusive direct link between the size of antigenic jumps and changes in influenza dynamics at the population level (6, 19–21).     

The influenza pandemic of 1918–1919 in Sri Lanka: its demographic cost,timing, and propagation

Background

As an island and a former British colony, Sri Lanka is a case of special interest for the study of 1918–1919 influenza pandemic because of its potential for isolation from as well as integration into the world epidemiologic system.

Objectives

To estimate population loss attributable to the influenza pandemic and weekly district-level excess mortality from the pandemic to analyze its spread across the island.

Methods

To measure population loss, we estimated a population growth model using a panel of 100 district-level observations on population for five consecutive censuses from 1891 to 1931, allowing for a one-time drop in population in 1918–1919. To estimate weekly excess mortality from the pandemic, we estimated a seasonally adjusted weekly time series of district-specific mortality estimates from vital registration records, ranked them, and plotted the ranks on weekly maps to create a picture of the geographic pattern of propagation across Sri Lanka.

Results

Total loss of population from the influenza pandemic was 307 000 or approximately 6·7% of the population. The pandemic peaked in two discrete (northern and southern) regions in early October of 1918 and in a third (central) region in early March 1919.

Conclusions

The population loss estimate is significantly higher than earlier estimates of mortality from the pandemic in Sri Lanka, suggesting underreporting of influenza-attributable deaths and a role for influenza-related fertility declines. The spatial pattern of peak mortality indicates the presence of two distinct entry points and three distinct epidemiologic regions, defined by population density and ethnicity, in colonial Sri Lanka.     

从"湿热疫毒"诊治24例新型冠状病毒肺炎的临床研究及体会

目的 总结自拟协定方治疗新型冠状病毒肺炎（COVID-19）的效果,分析从"湿热疫毒"诊治及防治病情进展的思路与方法。方法 选取2020年2月3日至18日在北京市回民医院连续住院的24例新型冠状病毒肺炎24例患者作为研究对象。所有患者在常规抗病毒及对症治疗的基础上,全程服用自拟协定方治疗。疗程6~14 d。通过体温、症状、白细胞（white blood cell,WBC）、中性粒细胞（neutrophil,NE）和淋巴细胞计数（lymphocyte,LY）及中性粒细胞淋巴细胞比值（neutrophil lymphocyte ratio,NLR）、胸部电子计算机断层扫描（computed tomography,CT）的改变评价疗效。结果 研究显示该病传染性强、以发热、咽干、咽痛、咳嗽、乏力及肌肉酸痛、纳差、腹泻、舌红、黄腻苔为主要临床表现,属湿热疫毒、侵袭肺胃。24例患者中,15例发热患者平均热程（从开始发热到体温正常的时间）（6.23±3.67）d。呼吸消化道及神经系统等临床症状均得到改善。23例患者治疗前后复测血常规,入院时降低的WBC、NE及LY有显著提升,差异有统计学意义（P<0.01）。值得注意的是本研究中50岁以上患者入院时NLR>3.13的5例患者CT显示炎性反应明显吸收,3例经过治疗后,NLR降至2.90以下。22例入院胸部CT检查符合肺炎改变者,治疗后21例复测胸部CT。结果显示,6例患者CT显示炎性反应明显吸收,11例患者CT显示炎性反应部分吸收,3例患者CT无明显变化,CT好转率80.95%。2例CT有加重者均为60岁以上,NLR>3.13,出现血氧饱和度（oxygen saturation,SpO₂）下降,1例转院,1例及时应用祛湿排痈化瘀药物显著好转,NLR下降至2.90,SpO₂上升至95%以上,胸部CT显示大部分病灶范围缩小。由普通转重型1例占4.2%。结论 依据"湿热疫毒"拟中药协定方治疗新型冠状病毒肺炎效果显著。对素有络脉瘀阻或存在基础疾病的中老年人群,建议重视早期化瘀通络,有湿热蕴毒、闭肺趋势者,建议清利排痰消壅、解毒逐瘀通络防治病情进展。     

诺如病毒感染宿主免疫应答的研究进展

诺如病毒是引起非细菌性急性感染性胃肠炎的主要病原体,常常引起严重的公共卫生与食品安全问题。诺如病毒疫苗的研发被越来越多的国家提上日程,疫苗的研制和应用依赖于对宿主和病毒相互关系的深入了解,依赖于宿主对病毒的免疫应答机制的了解。本文综述了诺如病毒国内外流行现状、诺如病毒感染与HBGAs受体关系和诺如病毒感染人或动物后机体的免疫应答研究现状。     

基于“肺与大肠相表里”再认识的新型冠状病毒肺炎治疗

[目的]分析杭州地区普通型新型冠状病毒肺炎确诊患者中医证候特点及病因病机,为临床诊疗提供依据。[方法]对符合普通型新型冠状病毒肺炎诊断标准的77例患者,收集人口学资料、流行病学资料、血液检查数据、胸部CT平扫报告、中医证候特征、舌象和脉象等信息进行研究分析。[结果]普通型新型冠状病毒肺炎患者平均年龄(44.13±13.62)岁;74.03%的患者有新冠肺炎患者密切接触史或湖北地区旅居史,29.87%的患者为聚集性病例;多数患者白细胞计数正常或减低(93.51%),淋巴细胞计数减低(40.25%),C反应蛋白升高(46.75%),胸部CT提示病毒性炎症改变(90.91%);半数以上患者有咳嗽(61.04%)、发热(50.65%)等症状;舌质以淡红舌或红舌为主(83.12%),舌苔以白腻苔(46.75%)多见,脉象以濡脉较多(45.45%);证型以湿毒郁肺型(72.73%)为主,少数患者为疫毒闭肺型(27.27%)。[结论]杭州地区普通型新型冠状病毒肺炎初步分析以湿毒郁肺型为主,属"湿毒疫",符合中医湿疫的特点。     

中药在新冠肺炎防治中的应用和研究进展

中医药早期介入、中西医结合治疗是提高新型冠状病毒肺炎(简称"新冠肺炎",COVID-19)治愈率、降低病死率的重要手段。综述中药防治新冠肺炎的药理依据和临床应用,以及防治新冠肺炎中药的研究策略,特别介绍了本次新冠肺炎防控中临床应用有效的中药复方如清肺排毒汤等。在传承中医药理论和原则基础上,坚持以中医药理论为指导,同时借助大数据、人工智能和系统生物学等先进技术和手段,通过多学科交叉构建多水平、多维度的药效筛选和评价研究体系,从而更系统、深入和全面地揭示中药药效物质基础、作用靶点、作用机制,进一步挖掘中医药精髓。     

1990-2012年高县甲型病毒性肝炎流行趋势分析

目的了解高县甲型病毒性肝炎流行病学趋势,为制定控制策略提供科学依据。方法对高县1990-2012年甲型病毒性肝炎疫情资料,采用描述性流行病学分析方法进行统计分析。结果1990-2012年共报告甲型病毒性肝炎1238例,死亡病例4例,年平均发病率和死亡率为11.06/10万和0.04/10万;发病率最高年份为1991年(31.02/10万),最低年份为2010年(1.26/10万);1990-2012年间年平均发病率经趋势卡方检验,差异有统计学意义(χ2=126.99,P0.01);累计各年每月均有病例发生,少年和青壮年农民发病占总病例数的65.19%,男女病例性别比1.57∶1。结论高县1990-2012年间甲型毒性肝炎年发病率总体呈现逐年下降趋势,发病数以少年和青壮年农民为主。     

楚雄市血吸虫病传播阻断后疫情分析

目的了解云南省楚雄市血吸虫病传播阻断后疫情趋势,评估防治效果。方法收集楚雄市1994-2012年血吸虫病疫情资料,分析人畜病情和螺情的变化,比较逐年血吸虫病疫情指标变化趋势。结果楚雄市1993年达到血吸虫病传播阻断标准后,无新感染血吸虫病患者、病畜和感染性钉螺发现,活螺密度明显下降,分别由1994年的0.69只/0.1m2降至2012年0.0075只/0.1m2;但钉螺面积回升,有螺面积在2.45~28.04hm2,最严重时出现在2004年和2005年,2012年仍有钉螺面积6.17hm2。结论楚雄市达血吸虫病传播阻断标准后病情稳定,但螺情形势严峻,今后应加大外来传染源监测和钉螺控制力度,以巩固防治成果。