Hemorrhagic fever with renal syndrome (HFRS) is a category B infectious disease caused by hantaviruses that cause acute kidney injury and has a high mortality rate, and HFRS control has been given a high priority in China. It has been found that hantavirus types are closely associated with selective host transformation and regional adaption, and continue to evolve in the form of gene recombination. The severity of HFRS varies in hantavirus types. In addition, global environmental changes and alteration of host animal behaviors accelerate Hantavirus genome variations, and large-scale land reclamation and infrastructure building increases the likelihood of human contacts with hosts and disease-transmitting vectors, thereby increasing the risk of HFRS development. This review summarizes the main characteristics and influencing factors pertaining to the epidemic process of HFRS, so as to provide insights into effective prevention and control of this infectious disease.
［摘要］ 肾综合征出血热 (hemorrhagic fever with renal syndrome, HFRS) 是由汉坦病毒 (hantavirus) 感染引起的一种乙类 传染病, 可引发急性肾损伤, 病死率较高。汉坦病毒型别与选择性宿主转换和地区适应密切相关, 并由此不断以基因重 组等方式进化, 不同型别汉坦病毒所致疾病严重程度不同。全球环境变化及宿主动物习性改变加速了汉坦病毒基因组 变异; 同时, 我国大规模土地改造、基础设施建设也使人群与病毒宿主和疾病传播媒介的接触机会增加, 一定程度上增大 了人群患病风险。本文综述了肾综合征出血热流行过程的主要特征及其相关影响因素, 为有效防控该疾病的发生和流 行提供参考依据。.

Since the outbreak of coronavirus disease 2019 (COVID-19) in late December 2019, it has brought significant harm and challenges to over 200 countries and regions around the world. However, there is increasing evidence that many patients with COVID-19 are asymptomatic or have only mild symptoms, but they are able to transmit the virus to others. There are difficulties in screening for asymptomatic infections, which makes it more difficult for national prevention and control of this epidemic. This article reviews the characteristics, treatment, and outcomes of asymptomatic infections with COVID-19, hoping it would be helpful for early prevention and control of this severe public health threat worldwide.

Objective: To understand the epidemiological and etiological characteristics of outbreaks on acute gastroenteritis caused by sapovirus (SaV) worldwide. Methods: Literature about the outbreaks on acute gastroenteritis caused by SaV were retrieved from the databases including WanFang, CNKI, PubMed and Web of Science after evaluation. Time, geography, setting and population distributions of outbreaks, transmission mode, SaV genotype and clinical characteristics of the patients were analyzed. Results: A total of 34 papers about SaV were included, involving 146 outbreaks occurred between October 1976 and April 2016. In these papers, 138 outbreaks were reported on the related months. All these outbreaks occurred in northern hemisphere. SaV outbreaks occurred all year around, but mainly in cold season, the incidence was highest in December (25 outbreaks) and lowest in in August (2 outbreaks). Most outbreaks were reported by Japan, followed by Canada, the United States of America and the Netherlands. There were 141 outbreaks for which the occurring settings were reported, child-care settings were most commonly reported setting (48/141, 34.04%), followed by long-term care facility (41/141, 29.08%) and hospital (16/141, 11.35%). Clinical symptoms of 1 704 cases in 31 outbreaks were reported, with the most common symptom was diarrhea (1 331/1 704, 78.12%), followed by nausea (829/1 198, 69.20%), abdominal pain (840/1 328, 63.25%), vomiting (824/1 704, 48.36%) and fever (529/1 531, 34.53%). Genotypes of SaV were determined for 119 outbreaks. GⅠ(51/119, 42.86%) and GⅣ (45/119, 37.82%) were predominant. The outbreaks of GⅣ SaV increased suddenly in 2007, and the outbreaks of GⅠ SaV mainly occurred in 2008 and during 2011-2013. Conclusions: SaV outbreaks were reported mainly by developed countries, with most outbreaks occurred in cold season, in child-care settings and long term care facility. GⅠ and GⅣ were the most common genotypes of SaV. Prevention and control of SaV outbreak in China seemed relatively weak, and it is necessary to conduct related training and to strengthen the SaV outbreak surveillance in areas where service is in need.
目的： 了解全球札如病毒（SaV）急性胃肠炎暴发的流行病学及病原学特征。 方法： 通过万方、中国知网、PubMed、Web of Science等数据库，检索2018年1月以前发表的SaV急性胃肠炎暴发文献，对文献进行评价和筛选，分析暴发的时间分布、地区分布、场所分布、人群分布、传播途径、病原学特征、患者临床症状等。 结果： 共收集到34篇SaV暴发文献，涉及146起暴发，发生时间范围为1976年10月至2016年4月。138起暴发报告了发生月份，均来自北半球，全年均有发生，8月发生最少，12月发生最多，主要发生于温度较低月份。报告暴发较多国家为日本、加拿大、美国和荷兰。共141起暴发提供了发生场所，常见的为托幼机构（48/141，34.04%）、长期看护机构（41/141，29.08%）和医院（16/141，11.35%）。31起暴发共1 704例病例具有临床症状信息，腹泻最常见（1 331/1 704，78.12%），然后分别为恶心（829/1 198，69.20%）、腹痛（840/1 328，63.25%）、呕吐（824/1 704，48.36%）和发热（529/1 531，34.53%）。119起暴发确定了病毒型别，其中GⅠ组（51/119，42.86%）和GⅣ组（45/119，37.82%）SaV较为常见，GⅣ组SaV引起的暴发在2007年突然增加，GⅠ组导致的暴发则在2008、2011－2013年报告较多。 结论： SaV暴发主要为发达国家报告，寒冷月份高发，常发生于托幼机构和长期看护机构，主要流行株为GⅠ组和GⅣ组。我国SaV暴发防控工作较为落后，需开展相应的培训工作，在有条件的地区开展SaV暴发监测工作。.