Efficacy of three candidate Rift Valley fever vaccines in sheep

Rift Valley fever virus (RVFV) is a mosquito-transmitted Bunyavirus that causes high morbidity and mortality among ruminants and humans. The virus is endemic to the African continent and the Arabian Peninsula and continues to spread into new areas. The explosive nature of RVF outbreaks requires that vaccines provide swift protection after a single vaccination. We recently developed several candidate vaccines and here report their efficacy in lambs within three weeks after a single vaccination. The first vaccine comprises the purified ectodomain of the Gn structural glycoprotein formulated in a water-in-oil adjuvant. The second vaccine is based on a Newcastle disease virus-based vector that produces both RVFV structural glycoproteins Gn and Gc. The third vaccine comprises a recently developed nonspreading RVFV. The latter two vaccines were administered without adjuvant. The inactivated whole virus-based vaccine produced by Onderstepoort Biological Products was used as a positive control. Five out of six mock-vaccinated lambs developed high viremia and fever and one lamb succumbed to the challenge infection. A single vaccination with each vaccine resulted in a neutralizing antibody response within three weeks after vaccination and protected lambs from viremia, pyrexia and mortality.     

建立国际航行船舶媒介生物监测预警系统的思路

随着全球经济一体化和海运业的蓬勃发展，媒介生物以国际航行船舶、集装箱、货物等为载体侵入我国，对我国人民和动物的健康构成极大威胁。为了保障我国的卫生安全和经济安全、应对国外技术性贸易措施和履行即将实施的新《国际卫生条例》，在科学性和实用性原则的基础上，提出建立国际航行船舶媒介生物监测预警系统。该系统框架包括4部分：媒介生物信息模块、国际航行船舶媒介生物监测模块、媒介生物风险评估模块和国际航行船舶媒介生物风险预测管理模块。实现这一系统，我们必须：采用相同的方法和标准、长期坚持媒介生物监测工作、开发应用计算机软件、加大财力投入和培养人才。     

Malaria vector control strategies. What is appropriate towards sustainable global eradication?

Malaria a mosquito-borne disease caused by Plasmodium remains to be a main global burden despite concerted efforts to eliminate it. While diverse control strategies have been put in place for mosquito-borne diseases, vector control continues to be a critical component in infection prevention. Vector control majorly focuses on the eradication of mosquitoes using a variety of chemical insecticides that includes organochlorides, carbamates, organophosphates, and pyrethroids. The use of conventional insecticide-based as mosquito control strategies poses several challenges such as the widespread development of insecticide resistance, environmental damage concerns, and effects on non-target organisms. These challenges create a demand for the development and use of alternative pest control strategies that are sustainable, safer, and environmentally friendly to mosquito vector management. This review provides insight into alternative sustainable interventions for mosquito vector control in the form of biorational pesticides. Biorational pesticides are pesticides that have little or no effect on humans and environments and include entomopathogenic microorganisms, insect growth regulators, and endosymbiotic bacteria. It also puts into perspective their environmental impacts, benefits, and challenges. Further, countries like Sri Lanka, that are certified as malaria free by World Health Organization (WHO) incorporated the use of entomopathogenic bacteria, insect growth regulators and larvivorous fish in their national vector control programs leading to the successful elimination of malaria in 2016. We therefore highlight success stories of the countries that have implemented these interventions bringing out the lessons for countries that are battling malaria epidemics.     

Assessment of an immunomarking technique for the study of dispersal of Culicoides biting midges

Capture–mark–recapture techniques are used to determine the dispersal and survival of arthropods, including vector groups such as Culicoides. An assumption of these studies is that capture and the subsequent marking process does not impact of the survival and behaviour of the marked individual. The small size of Culicoides means that a significant mortality and disruption of normal behaviour such as host-location can be caused by the process of collection. Here we evaluate a technique, novel to the study of dispersal in vectors, to mark Culicoides directly and indirectly without prior capture. The acquisition and subsequent detection of marker protein by Culicoides exposed to a treated substrate was investigated in the laboratory. The technique was then assessed in a small-scale field trial where a defined section of resting habitat was sprayed with an egg white solution and Culicoides caught within the vicinity were tested for the presence of egg protein. It was found that up to 100% of Culicoides acquired the protein marker in the laboratory with no apparent impact on survival. In the field, pools of Culicoides obsoletus collected next to the treated area were found to be positive for the protein, suggesting that the technique could be used in larger-scale studies. The definition of a behaviourally non-invasive technique for marking Culicoides will greatly increase our understanding of the natural dispersal behaviour of Culicoides and other vectors.     

VAR模型在我国人口出生率预测中的应用

摘要:目的　基于我国人均GDP,使用向量自回归模型预测我国人口出生率,探讨其在我国卫生领域应用的可行性。方法　收集1952-2013年我国人均GDP及人口出生率资料,用Excel2007和Eviews8.0建立VAR模型,并用2012-2013年的数据评价模型的预测效果。结果　VAR（2）模型拟合及预测的平均相对误差和希尔不等系数分别为8.78%,0.146和3.903%,0.087。结论　VAR（2）模型对我国人口出生率的拟合精度较高,短期预测效果较好。     

枯草芽孢杆菌guaB基因克隆及其在大肠杆菌中的表达

克隆枯草芽孢杆菌guaB基因,构建穿梭表达载体,使其在大肠杆菌中获得表达,为构建鸟苷高产工程菌奠定基础。从枯草芽孢杆菌JSIM-G-518基因组扩增出guaB基因,将其连接到pMD19-T上,得到重组质粒pMD-guaB,进行测序和Blast比对分析。该重组质粒经PstI、BamHI双酶切,获得guaB片段连接至pHP13载体上,构建穿梭表达载体pHP13-guaB,并采用双酶切电泳进行鉴定。将该载体转化入大肠杆菌BL21中,通过SDS-PAGE电泳检测guaB基因的表达效果。克隆的guaB基因长度为1 510 bp,与GenBank登录的枯草芽孢杆菌同源性为99%,编码500个氨基酸,确认为控制IMP脱氢酶的基因。穿梭载体pHP13-guaB经双酶切后产生1 510 bp和4.9 kb两个期望的目的条带。SDS-PAGE结果显示表达产物相对分子质量的大小为52.9 k,与预期的IMP脱氢酶分子量一致,且该目的蛋白的表达效果比对照组更明显。论文成功实现了枯草芽孢杆菌guaB基因在大肠杆菌中的表达。     

广东省主要媒介害虫抗药性现状、对策研究及其应用

目的：研究广东省主要媒介害虫的抗药性现状及其防制对策。方法：生物测定法、酯酶滤纸法、ＰＣＲ技术及药激法。结果：经系统监测,广东省各监测点主要媒介对常用杀虫剂大部分都产生抗性,个别品系株已产生高度抗性。采用酯酶滤纸法快速检测家蝇抗药性及应用ＰＣＲ技术监测家蝇抗药性的研究,发现家蝇个体α－Ｎａ酯酶活性频率分布（ＥＦ５０值）与家蝇对ＤＤＶＰ、巴沙的敏感性（ＬＤ５０）呈一定的相关关系。ＤＤＶＰ、巴沙对家蝇     

福州口岸诱卵器法的现场应用研究

目的进一步研究诱卵器法在口岸媒介监测现场的应用技术。方法诱卵器法。结果 （1）诱卵器放置不同高度时,0m组和1m组的诱卵指数分别为87.68和83.79,0m组高于1m组（χ2=13.24,P〈0.005）,0m组和1m组的幼虫密度分别为13.21条/个和11.23条/个,0m组高于1m组（t=2.259,P=0.05）;（2）诱卵器放置不同时间时,4d、7d和10 d组的诱卵指数分别为28.00、74.50和76.41,4 d组低于7 d组（χ2=86.54,P=0.000）和10 d组（χ2=92.69,P=0.000）,4d、7d和10d组幼虫密度分别为2.095条/个、9.11条/个和11.36条/个,4d组低于7d组（t=2.334,P=0.024）,7d组低于10 d组（t=4.691,P=0.000）;（3）诱卵指数和幼虫密度呈较为密切的正相关（0 m组r=0.779,P=0.008;1 m组r=0.794,P=0.006）,不同监测时间和监测点诱卵指数和容器指数的关系需进一步研究。结论在福州口岸建议诱卵器放置在地面上,放置时间为7～10d,以提高成蚊产卵率,增加敏感性;需进一步研究诱卵器法和布雷图指数、房屋指数和容器指数在口岸地区的关联性,探索评价指标的推广应用。     

河南省淮滨县实施全球基金疟疾项目效果的评价

[目的]评价河南省淮滨县2003～2005年实施全球基金疟疾项目期间的疟疾疫情、防治措施及防治效果。[方法]收集淮滨县2003～2005年疟疾流行、防治措施、防治效果及媒介监测资料,分析流行情况,评价防治措施及效果。[结果]2003～2005年淮滨县共报告疟疾病例1765例,平均年发病率为8.93/万。2004年和2005年疟疾发病分别比上年下降53.58%和72.04%。建立发热病人镜检站18个,血检发热病人39070人,发现650例阳性病人。捕获中华按蚊4744只,未发现嗜人按蚊,疟疾暴发发点氟氯氰菊酯药物浸泡蚊帐340顶。氯、伯喹治疗现症病人1765人,休止期服药7571人,流行季节预防服药2471人。培训专业技术116人次,疟防宣传6259份,督导检查108次。居民和中小学生疟防知识知晓率由2003年的14.36%和9.36%提高到2004年的54.21%和47.36%。2005年144例疟疾病人平均确诊时间(2.82±2.89d)显著低于河南省的平均确诊时间(6.64±10.49d)(单样本t检验,t=-15.844,P=0.000)。[结论]在全球基金疟疾项目的支持下,河南省淮滨县疟防工作成绩显著,以项目管理促进疟防的方式值得推广。     

横琴口岸蜚蠊种群构成及季节消长

目的掌握横琴口岸地区蜚蠊的种群构成及其密度的变化规律,为口岸防控蜚蠊,防止传染病传播提供依据。方法用诱蟑盒诱捕。从2004.3~2005.2,每月上下旬各调查一晚,将捕获的蜚蠊带回实验室鉴定,分类,计数。结果共布盒1440个,捕获蜚蠊965只,以美洲大蠊为优势种,占72.5%。全年平均密度0.67只/(盒·夜),6月份密度最高为1.717只/(盒·夜),2月份密度最低为0只/(盒·夜)。结论横琴口岸地区蜚蠊密度不高,有明显季节性,4~7月为活动高峰期,进行杀灭效果较好。