从 2013 年年末开始，以基孔肯雅、寨卡、黄热病、登革热、西尼罗河等虫媒传染病开始在西半球活跃，引起了全球的广泛关注。 2013 年，基孔肯雅病毒和寨卡病毒被认为首先出现在西半球，这两种病毒影响许多拉丁美洲和加勒比海地区的人，也直接威胁着美国。 2013 年底，基孔肯雅病毒首次出现在加勒比海圣马丁岛上，并从那以后扩散到美洲的绝大部分地区。 2013-2014 年在大洋洲的法属波利尼西亚岛屿上发生了一次较大的寨卡病毒流行，感染了约 32000 人。基因分析研究表明， 2015 年发生在南美洲的寨卡病毒可能是在 2013 年 5 月和 12 月之间首次进入美洲，随后在整个拉丁美洲和加勒比海地区扩散。从 2016 年 12 月开始在巴西爆发的黄热病疫情是近几十年来最严重的一次，疫情集中在丛林和农村地区，城市中并未发现疫情。巴西全国共出现黄热病 777 例，死亡 261 例。从南美洲到南亚，世界多个国家在 2013 年爆发登革热疫情。 2011-2013 年泛美卫生组织分别报告登革热病例 1093252 例， 1120902 例， 2386836 例，发病率分别为 208.8/10 万、 214.1/10 万、 455.9/10 万， 2013 年的发病率是明显高于前两年。 2016 年 12 月到 2017 年 8 月，巴西全国共出现黄热病 777 例，死亡 261 例。此次疫情主要集中在丛林和农村地区，并且是几十年来最严重的一次。 Peter Hotez 在一项研究中报道在欧洲南部出现的同样令人担忧的局面，已经观察到虫媒病毒感染如登革热病毒、基孔肯雅病毒和西尼罗河病毒感染在增加。 尽管五种虫媒病毒感染在西半球快速传播令人印象深刻，但是这些疾病为什么会突然大幅增加的原因仍然不是很清楚。 PLOS Neglected Tropical Diaseases 期刊主编 Peter Hotez指出一种奇怪的“新常态”可能正在热带感染性疾病中发生。为了弄明白这一点，我们将需要抛弃我们的学术孤岛（academic silos，即学术上相互隔离，不进行合作和沟通）和舒适地带，与新领域的科学家们合作，以便解决这些新的现象。 Peter Hotez 在早些时候发布的研究中提出人类活动产生的新力量，包括气候变化、森林砍伐、城市化和贫穷，可能是重要的影响因素 . 。近些年来，尽管通过广泛的药物服用和其他的方法，在预防和治疗疟疾等一些被忽视的热带疾病中取得重大进展，但是整体上看主要的媒介传播的被忽视热带疾病显著增加。我们的研究发现 2013 年开始出现的五种虫媒传染病的大幅增加与西半球急剧减弱的地磁场的分布高度一致。以前的研究表明，蚊虫是一种对磁场敏感的昆虫，磁场的减弱能够增加蚊虫的繁殖速度和空间密度。从 2013 年年末出现的五种虫媒传染病主要是通过蚊虫叮咬传播的，西半球地磁场的快速减弱很可能促进蚊虫密度的增加，进而加速这些虫媒传染病传染病的快速传播。 Weakened Magnetic Field and the Resurgence of Mosquito-Borne Arboviruses Jiangwen Qu 1 and Chandra Wickramasinghe N 2,3,4* 1 Department of Infectious Disease Control, Tianjin Centers for Disease Control and Prevention, China 2 Buckingham Centre for Astrobiology, University of Buckingham, UK. 3 Sri Lanka Centre for Astrobiology, University of Ruhuna, Sri Lanka 4 General Sir John KotelawalaDefence University, Sri Lanka * Corresponding Author: Chandra Wickramasinghe N, Buckingham Centre for Astrobiology, University of Buckingham, UK Short Commentary Five epidemics of mosquito-borne arboviruses- Zika virus (ZIKV), Dengue virus (DENV), Yellow Fevervirus (YFV), West Nile virus (WNV) and Chikungunya virus (CHIKV) have emerged in the Western Hemisphere, particularly in South America since late 2013. The reason we are seeing such a sudden, sharp rise in these mosquito-borne arboviruses is unknown. Although climate change, mass human migrations and poor hygiene are often cited as primary causes for the sudden resurgence, it is likely that a more fundamental cause exists, and its discovery could have a profound effect in determining future public health strategy . In June 2014, after just six months collecting data, ESA’s Swarm programme confirmed the general trend of the magnetic field’s weakening, with the most dramatic declines over the Western Hemisphere; but in other areas, such as the southern Indian Ocean, the magnetic field had strengthened since January (Figure 1). Figure 1: Changes in Earth’s magnetic field from January to June 2014 as measured by the Swarm constellation of satellites. Shades of red represent areas of strengthening, while blues show areas of weakening over the 6-month period. New data released by the European Space Agency (ESA) reveals that our geomagnetic field is weakening by around 5% a year, which is nearly ten times faster than previous estimates . Furthermore, this effect is not uniform over the Earth; the field is weakening faster in some places than others. For example, the South Atlantic Anomaly (SAA) is a large depression of the Earth's magnetic field characterized by values of geomagnetic field intensity that are around 30% lower than expected for those latitudes. This region covers a large area in the South Atlantic Ocean and South America. According to Swarm satellite monitoring results, Earth's magnetic poles may be getting ready to flip, the field has weakened by about 3.5% at high latitudes over North America, while it has strengthened about 2% over Asia . The region where the field is weakest – the South Atlantic Anomaly – has moved steadily westward and weakened further by about 2% between 1999 and May 2016 . Previous studies have suggested that the mosquito is an insect sensitive to the magnetic field, and the weakening of the magnetic field may have increased the mosquito's reproductive speed and spatial density . The currently emerging arbovirus epidemics in the past four years are mostly transmitted to humans by bites from mosquitos vectors. The rapid weakening of Earth's magnetic field in the Western Hemisphere probably speeded up an increase in the population of mosquitoes thus promoting the rapid spread of these mosquito-borne arboviruses. Thus, we make the bold suggestion that a surveillance of magnetic field may serve as a potential warning of future mosquito-borne arboviruses. Together with other epidemiological data such information might prove to be a useful factor for strategic disease control planning of mosquito-borne arboviruses. Acknowledgements Data on the number of Earth’s magnetic field were provided by European Space Agency (ESA) http://www.esa.int/Our_Activities/Observing_the_Earth/Swarm/Swarm_reveals_Earth_s_changing_magnetism Author contributions These authors contributed equally to this work. Competing Interests The authors have declared that no competing interests exist. References Hotez PJ (2016) Southern Europe’s Coming Plagues: Vector-Borne Neglected Tropical Diseases. PLOS Neglected Tropical Diseases 10: 1-6. Christopher F, Nils O, Stavros K, et al. (2016) Recent geomagnetic secular variation from Swarm and ground observatories as estimated in the CHAOS‑6 geomagnetic field model. Earth, Planets and Space 68: 112 Pavón-Carrasco, F. Javier; De Santis, Angelo. The South Atlantic Anomaly: The Key for a Possible Geomagnetic Reversal. Frontiers in Earth Science 4:40. http://www.esa.int/Our_Activities/Observing_the_Earth/Swarm/Earth_s_magnetic_heartbeat Pan H, Liu X (2004) Apparent Biological Effect of Strong Magnetic Field on Mosquito Egg Hatching. Bioelectromagnetics 25: 84-91. http://sciencetxt.org/open_access/weakened_magnetic_field_and_the_resurgence_of_mosquito_borne_arboviruses_IDI IDI-2-103 (2).pdf 关注多种媒介传播的被忽视热带疾病 来源：生物谷 2016-07-10 21:03 2016年7月10日/生物谷BIOON/-- 作为 PLOS Neglected Tropical Diaseases 期刊的共同主编，Peter Hotez和Serap Aksoy关注着全世界近期不断增加的多种媒介传播的被忽视热带疾病（neglected tropical disease, NTD）。 2013年，基孔肯雅病毒和寨卡病毒被认为首先出现在西半球，如今在那里，这两种病毒影响许多拉丁美洲和加勒比海地区的人，而且也威胁着美国。 2013年底，基孔肯雅病毒首次出现在加勒比海圣马丁岛上，从那以后扩散到美洲的绝大部分地区，包括今年在美国德克萨斯州报道的首例输入性感染病例。 类似地，分子钟研究表明寨卡病毒可能是在2013年5月和12月之间首次进入美洲，随后在整个拉丁美洲和加勒比海地区扩散，而且令人担忧的是，在今年夏天晚些时候，寨卡病毒可能开始传播到美国本土。 更令人担忧的是，今年4月份，美国疾病防治中心（CDC）首次声称是寨卡病毒（ZIKV）导致小头畸形和其他的出生缺陷，而不再猜测它们之间可能存在关联，并建议孕妇或者计划怀孕的女性最好不要前往寨卡病毒仍在传播的国家和地区。此外，美国CDC报道了一例ZIKV感染病例是男同性恋之间通过肛交进行传播的。 同样是在今年4月份，法国研究人员证实寨卡病毒（ZIKV）能够通过性接触进行传播。他们的分析表明在巴西感染上这种病毒的一名男子体内存在的病毒与从未到ZIKV流行病发生区域旅游但与这名男性发生性关系的一名女性体内存在的ZIKV存在100%的遗传相关性。 此外，在今年3月，研究人员在一项发表在 Lancet 期刊上的研究中，发现更多证据表明寨卡病毒感染还会引起一些病人发生暂时性瘫痪：古兰-巴雷综合征（GBS, Guillain-Barre syndrome）。最近拉丁美洲发生突发性瘫痪的病人出现增加，专家认为这与寨卡病毒爆发有关，而该研究的数据则进一步支持了这一理论。 而在今年6月份，来自美国华盛顿大学和科罗拉多大学等机构的研究人员发现最为严重的西尼罗河病毒（West Nile virus, WNV）感染并不杀死神经元，但会激活小胶质细胞和补体途径，这有助抵抗这种感染但最终会破坏突触，导致突触减少，从而最终导致一些WNV感染者出现记忆丧失和情感障碍等症状，从而为开发出治疗这种蚊子传播疾病的新疗法开辟新的道路。 尽管这些虫媒病毒感染在西半球快速传播令人印象深刻，但是这个月，Peter Hotez在一项研究中报道在欧洲南部出现的同样令人担忧的局面：在那里，最近几年，我们也观察到虫媒病毒感染如登革热病毒、基孔肯雅病毒和西尼罗河病毒感染在增加，除此之外，还观察到利什曼病（由利什曼原虫引起的人畜共患病）和甚至血吸虫病（通过钉螺进行传播）在增加。 确实，尽管通过广泛的药物服用和其他的方法，在预防和治疗疟疾和一些被忽视的热带疾病中取得重大进展，但是整体上，我们还是观察到主要的媒介传播的被忽视热带疾病显著增加。 我们观察到这些热带感染性疾病在增加的原因仍是不清楚的。在另一项今年早些时候发布的研究中，Peter Hotez提出人类活动产生的新力量，包括气候变化、森林砍伐、城市化和贫穷，可能是重要的因素。 因此，从中学到的教训是为了理解复杂的事件，如在拉丁美洲和欧洲发生的媒介传播的被忽视热带疾病增加，我们将需要考虑在对热带感染性疾病感兴趣的生物医学科学家、包括经济学家和人类学家在内的社会科学家和对环境感兴趣的地球科学家之间建立新的跨学科对话。 在早前的一项研究中，Peter Hotez指出一种奇怪的“新常态”可能正在热带感染性疾病中发生。为了弄明白这一点，我们将需要抛弃我们的学术孤岛（academic silos，即学术上相互隔离，不进行合作和沟通）和舒适地带，与新领域的科学家们合作，以便解决这些新的现象。 本着这种精神，美国国家科学基金会（US National Science Foundation）如今发起一项新的传染病生态学与进化（Ecology and Evolution of Infectious Diseases, EEID）计划。 这是一个好的开始！（生物谷 Bioon.com） 参考资料： 【1】 What's with these vector-borne neglected tropical diseases? 【2】Neglected Tropical Diseases in the Anthropocene: The Cases of Zika, Ebola, and Other Infections PLOS Neglected Tropical Diseases , doi: 10.1371/journal.pntd.0004648 【3】Southern Europe's Coming Plagues: Vector-Borne Neglected Tropical Diseases PLOS Neglected Tropical Diseases , doi: 10.1371/journal.pntd.0004243 【4】Zika virus in the Americas: Early epidemiological and genetic findings Science , doi: 10.1126/science.aaf5036 【5】 Nature：揭示西尼罗河病毒感染导致病人记忆丧失机制 【6】 【盘点】不要错过的寨卡病毒研究进展汇总 【7】Evidence of Sexual Transmission of Zika Virus New England Journal of Medicine , doi: 10.1056/NEJMc1604449 【8】Zika Virus as a Cause of Neurologic Disorders New England Journal of Medicine , doi: 10.1056/NEJMp1602708 【9】Why does Zika leave some patients paralyzed? Science , doi: 10.1126/science.aaf4144 http://news.bioon.com/article/6685391.html
海峡两岸学者近日研究发现，地磁倒转速率或可快于预期，并提出地球磁场近150年来已减弱10%到15%，若持续加速减弱，未来或可发生地磁倒转。 该研究成果发表在国际知名期刊 《美国科学院院报》 上。台湾大学周佑民博士、福建省湿润亚热带山地生态重点实验室——省部共建国家重点实验室培育基地的姜修洋教授和南方科技大学刘青松教授为研究论文共同第一作者，台湾大学沈川洲教授和周佑民博士为共同通讯作者。 为了研究历史上地球磁场倒转的速度和过程，研究人员在遵义三星洞采到含有磁铁矿的石笋标本，使用台湾大学地质系高精度的铀钍定年技术和中国科学院地质与地球物理所的低温超导磁力仪分析，经四年测量最后取得180个古地磁数据及70个定年点，成功重建了发生在十万年前、具有数十年际高分辨率、历时一万五千年的地磁纪录。 研究发现，在十万年前地球磁场很弱且非常不稳定，石笋数据显示出不断重复发生、相似性极高的不对称性地磁极南北飘移模式与周期。地磁极从正向仅需一百到几百年就快速倒转到反向，随后马上反弹，先转回到中低纬度区域，然后再历经数百年到数千年才慢慢转回高纬度的原正向位置。 更惊人的是，研究发现在九万八千年前，地磁极仅需一百到两百年之间，即可以从正向快速地完全倒转到反向。 福建省湿润亚热带山地生态重点实验室——省部共建国家重点实验室培育基地，由科技部和福建省依托福建师范大学共同建设。福建省科技厅基础处负责人表示，该研究论文分别受到国家自然科学基金和福建省科技厅资助。（来源：新华社 贺飞） Abstract Polarity reversals of the geomagnetic field have occurred through billions of years of Earth history and were first revealed in the early 20th century. Almost a century later, details of transitional field behavior during geomagnetic reversals and excursions remain poorly known. Here, we present a multidecadally resolved geomagnetic excursion record from a radioisotopically dated Chinese stalagmite at 107–91 thousand years before present with age precision of several decades. The duration of geomagnetic directional oscillations ranged from several centuries at 106–103 thousand years before present to millennia at 98–92 thousand years before present, with one abrupt reversal transition occurring in one to two centuries when the field was weakest. These features indicate prolonged geodynamo instability. Repeated asymmetrical interhemispheric polarity drifts associated with weak dipole fields likely originated in Earth’s deep interior. If such rapid polarity changes occurred in future, they could severely affect satellites and human society. http://www.pnas.org/content/115/36/8913 被称为“地球保护膜”的地磁场在加速减弱，有人怀疑它会发生逆转 研究发现，地球磁场正在加速减弱，这种状态已经持续了近一千年！ 有人怀疑地磁场要发生逆转。地磁场这个名词大家应该都听说过，但是地磁场怎样产生的？它有什么作用呢？ 什么是地磁场 百科里的解释是， 地磁场是指地球内部存在的天然磁性现象。 地球可视为一个磁偶极（magnetic dipole），其中一极位在地理北极附近，另一极位在地理南极附近。 通过这两个磁极的假想直线（磁轴）与地球的自转轴大约成 11.3 度的倾斜。地球的磁场向太空伸出数万公里形成地球磁圈引（magnetosphere）。 地球的磁场向太空绵延约 58,000 千米。地球的地核是可以导电的，就像个巨大的磁铁，它一直在旋转，这时候地球磁场就产生了。 地核的体积巨大，温度压力都很高，这时候地层导电率自然很高，电流像是在没有电阻的通路上传输，永不停歇，地球上磁场最稳定的地方就是南北两极。 什么叫磁场逆转 电子的分布位置并不是固定不变的，并会因许多的因素影响下会发生变化，再加上太阳和月亮的引力作用，地核的自转与地壳和地幔并不同步，这会产生一强大的交变电磁场，地球磁场的南北磁极因而发生一种低速运动，这种运动的积累将造成地球的南北磁极逆转。 地磁场有什么用呢？ 地磁场像是给地球罩上的保护套，像是一个泪珠形状的气泡，保护我们的地球表面免遭连续轰击地球的宇宙射线和带电粒子的伤害。 其实它就像是大气层一样，只不过大气层阻挡的是来自太阳的多余紫外线，让地球生物不至于被晒伤。 地磁场还保护着围绕地球旋转的成千上万颗卫星和其他航空器， 一旦地磁场消失了，外太空高能量辐射就会袭击赤裸裸的航空器，它们的命运便可想而知了。 150年里，地球磁场减弱了近10% 2014 年，科学家就曾做过类似研究，当时他们利用蜂群卫星对地磁场测量了 6 个月，结果发现地磁场在逐年减弱，而且西半球磁场减弱最为明显。 具体到数字就更令人震惊了，因为地磁场 150 年来减弱了将近 10%！此外研究还发现，地球磁场存在很大的地理差异。 在亚洲、太平洋地区磁场变化较小，非洲、欧洲和大西洋的变化非常大，变化最大的地区是非洲南端，在这个地区的磁场极性与正常的极性刚好相反。 大西洋南部磁场特别虚弱 欧空局观测时，惊讶的发现大西洋南部地球磁场异常弱，所以他们管这里叫南大西洋磁场异常区。 早前就有研究之处，这个区域的磁场仅为正常磁场的三分之一。而在最新研究里，科学家们发现这里磁场似乎更弱了。 但是源于什么，至今仍是未解之谜，原因是缺乏实地数据。因为这里的地磁场很弱，所以科学家们的一些研究设备在这里根本无法正常工作，所以才缺乏数据。 但是 科学家们猜测异常可能是因为南大西洋和北冰洋下方的液体金属地核可能出现了巨型涡流，从而影响了其上空的磁场。 由于巨型涡流的力量足以逆转其他涡流的方向，因此极有可能令地磁场南北极就此开始大逆转。 与气候变暖或有关联 2011 年，吉林大学地球探测科学与技术学院杨学祥教授等人曾研究过这个课题，并将成果写成论文发表。 他们认为， 地磁减弱的原因在于两极冰盖融化导致地壳和地幔转动惯量减少自转加快，由此引发核幔差异旋转在数值和方向上的改变。 在磁场减弱和磁极反向过程中，太阳辐射的增强和核幔热能的释放与灾害有一一对应关系。 追溯地球的历史，寒冷时期，地磁场往往较强，而高温时期，地磁场则较弱。所以也有科学家称，地磁场减弱可能在一定程度上影响了气候变暖。 2013 年，日本科学家也做了这项研究，结果与杨教授团队的成果不谋而合，他们发现冰盖大小出现变化后，地球自转速度就会受到影响。 为了调查地球自转速度变化与地球磁场变化的关系，研究小组利用计算机模型推算发现，地球磁场强度会随地球自转速度的变化而变化。即使自转速度只有 2% 的变化，磁场强度的变化会达到 20% 至 30%。 地球磁性曾在78万年以前逆转78万年前 因为地磁场在不断减弱，所以有人怀疑，地磁场是否会再次发生逆转？ 地球磁场在 600 年间确实发生过 3 次逆转，且彼此时间间隔不等。 最近一次发生在 78 万年前 。但是逆转也不是那么容易发生的，发生之前会有明显预兆，比如地磁场会剧烈减弱，甚至会出现零磁场。 但是现在的情况似乎没有那么糟糕，所以科学家们安抚大家不要惊慌，地磁场一时半会还不会逆转 \0 http://www.sohu.com/a/230094486_102883 \0
巴西黄热病毒变异 据新华社里约热内卢5月15日电 （记者赵焱 陈威华）巴西研究人员近日绘制出目前巴西流行的黄热病毒完整基因序列，由此分析出一些基因序列出现了变异。不过研究人员指出，黄热病疫苗对抵御这类变异病毒依然有效。巴西卫生部所属奥斯瓦尔多·克鲁斯基金会的研究人员说，科学界此前还没有记录过这类变异，但黄热病疫苗对抵御这类变异病毒依然有效。参与研究的巴西奥斯瓦尔多·克鲁斯基金会的米尔纳·博纳尔多说：“疫苗肯定还有保护作用，一剂疫苗可以保证到世界任何地方遇到任何种类的黄热病都有效。”从去年12月开始在巴西暴发的黄热病疫情是近几十年来最严重的一次，疫情集中在丛林和农村地区，城市中并未发现疫情。巴西卫生部最近的一次报告说，全国共确诊756例黄热病病例，259人死亡。疫情暴发以来，巴西奥斯瓦尔多·克鲁斯基金会研究人员就开始绘制病毒的基因组序列，首先使用的两份样品来自圣埃斯皮里图州今年2月死于黄热病的猴子。在全面分析后，研究人员发现一些蛋白参与病毒复制，导致病毒基因变异。研究成果刊登在该机构专业医学杂志《奥斯瓦尔多·克鲁斯研究所纪要》上。 http://www.jkb.com.cn/news/overseas/2017/0518/410265.html 中新社圣保罗5月12日电 (记者 莫成雄)当地时间5月12日，巴西卫生部发布新一期通报说，自从去年12月该国爆发黄热病疫情以来至今年5月10日，已确诊756例黄热病病例，其中259人因病死亡。 报告说，巴西卫生部共收到各级卫生部门通报的疑似黄热病病例3175例，已经排除1797例，确诊756例，还有622例待查。目前，巴西全国共有116个市镇发现有黄热病病例。东南部的米纳斯吉拉斯州是黄热病疫情重灾区，已确诊488例。其次是圣埃斯皮里图州，已确诊234例。这两个州死于黄热病的人数是全国最多的。圣保罗州、里约热内卢州和帕拉州也有死亡病例。巴西卫生部表示，目前所有的黄热病确诊病例均发生在农村地区以及部分内陆城镇，特别是森林等植被较密集的地区，大城市还未发现黄热病病例。黄热病是一种由黄热病毒引起的急性传染病，由蚊子叮咬传播，主要在非洲和拉丁美洲热带地区流行。其临床表现包括高热、头痛、黄疸、出血等，严重时可致死亡。黄热病目前尚无特效疗法，但接种疫苗可有效预防感染。(完) http://news.163.com/17/0513/13/CKAQAIG200018AOQ.html 巴西最近的黄热病疫情或与地磁场减弱和宇宙射线增强有关，具体分析见论文： IJCSMB.MS.ID.555636.pdf Weakened geomagnetic field, Cosm ic rays and the Resurgence of Yellow Fever Jiangwen Qu 1 , N.Chandra Wickramasinghe2,3* 1 Department of Infectious Disease Control, Tianjin Centers for Disease Control and Prevention, China ； 2 Buckingham Centre for Astrobiology, University of Buckingham, UK; 3 Sri Lanka Centre for Astrobiology, University of Ruhuna, Sri Lanka *Corresponding: N. Chandra Wickramasinghe, E-Mail: ncwick@gmail.com , Tel: +44 (0)2920752146 / +44 (0)7778389243 Abstract The yellow fever outbreak in Brazil pose a serious public health threat. Research on the environmental factors underlying yellow fever virus outbreak epidemiology may provide useful insights into the occurrence of yellow fever outbreak. This study suggested that the lowering of the geomagnetic field strength and a sudden increase of cosmic rays in Mexico in 2015 were associated with the emergence of the yellow fever outbreak in Brazil. Potential mechanisms by which weakened geomagnetic field and cosmic ray activity may influence yellow fever outbreak in humans are discussed. Current and future surveillance efforts should be supported to construct a comprehensive early warning system involving weakened geomagnetic field and cosmic ray activity for detecting future yellow fever outbreaks as early as possible. Whist Brazil is still recovering from the Zika virus outbreak, the south-east of this country has recently been struck by the largest outbreak of Yellow Fever (YF) in Latin Americain many decades. The outbreak, which began in 2016, has rapidly and alarmingly spread eastward, reaching the most populated regions of Brazil where vaccine coverage is inadequate, so raising public health concern about high rates of urban transmission and the spread of YF beyond Brazil’s national borders. Other viral diseases that appeared to flare up in South America roughly at the same time include the arboviruses dengue and chikungunya. Although climate change, and poor hygiene are cited as causes for this sudden resurgence of viral disease, it is possible that a more fundamental reason exists, and its discovery could have a profound effect in determining public health strategy. It is generally known that the Earth's magnetic field acts like a giant invisible bubble that shields the planet from the various mutagens such as solar particles and cosmic rays. Severe disruption of the magnetic field barrier would permit the ingress of damaging cosmic ray particles and also charged viral sized particles from outside the Earth. In the absence of other plausible causes is to such externally induced processes that we may be forced to turn in order to explain the unusual patterns of viral incidence we have witnessed in recent years. The role of cosmic rays in causing genetic changes is well known. It is also known at times of low sunspot activity the Earth’s magnetic field is less able to protect the Earth from energetic cosmic rays, including galactic cosmic rays. One particularly strong effect that has recently come to light is the decrease in the Earth’s magnetic field in the Southern Hemisphere, straddling land masses in South America and Africa. The geomagnetic map shown in Fig. 1 was obtained in 2015 at a time when many of the new pandemics of viral disease which we have discussed actually started sweeping across South America and Africa. We think this is unlikely to be a coincidence. Fig. 1 Intensity geomagnetic field map at 2015.0. Red represents areas where the magnetic field is stronger, while blues show areas where it is weaker. New data released by the European Space Agency (ESA) reveals that our geomagnetic field is weakening by around 5% a year, which is nearly ten times faster than previous estimates 1 . Furthermore, the field is weakening faster in some places than others. For example, the South Atlantic Anomaly (SAA) is a large depression of the Earth's magnetic field strength characterized by values of geomagnetic field intensity around 30% lower than expected for those latitudes and covers a large area in the South Atlantic Ocean and South America. According to the monitoring data of ESA's Swarm satellite, Earth's magnetic poles may be getting ready to flip, and the South Atlantic Anomaly where the field is particularly weak has moved steadily westward and weakened further by about 2% 2 . Previous studies have suggested that the mosquito is a sensitive animal to the magnetic field, and the weakening of the magnetic field can increase the mosquito's reproductive speed and density 3 . YF is mostly transmitted to humans by bites from infected Aedes spp, especially Aedes aegypti. The rapid weakening of Earth's magnetic field in the SAA probable speeds up the rapid increase of mosquitoes and promotes the rapid spread of the yellow fever virus. A sharp change of the magnetic field in this region (which includes South America and Brazil) allows cosmic rays, and charged particles to reach lower into the atmosphere. At present, solar activity is now at its most inactive stage in recent 100 years.The sunspot cycle (No.24) that peaked in 2014 showed the lowest sunspot number recorded since 1906 with many consecutive days of very low sunspot numbers in 2016/17 4 . Cosmic rays reach amaximum intensity when the earth's magnetic field is weakening dramatically and the sun is least active. According to the World Data Center for Cosmic Rays (WDCCR), there was a sudden increase of cosmic rays in Mexico in January 2015 and continued throughout the year 5 . The sudden increase of cosmic ray intensity in Mexico (North/South American region) is probably the cause of the ZIKV and YF outbreak. A new study revealed that solar radiation and cosmic rays are physical mutagens of natural genetic mutation/recombination, and can lead to the emergence of some emerging viruses like pandemic influenza 6 . Zika virus outbreak may have been linked to a systematic increase in the flux of cosmic rays and a general decline of sunspot activity 7 . Phylogenetic analysis of two yellow fever virus (YFV) samples collected during the current Brazilian epidemic revealed the 2016/17 epidemic virus is a new genetic lineage 8 . The weakened magnetic field and enhanced cosmic rays both contributed to the severe YFV outbreak. Thus, we make the bold suggestion that a surveillance of both magnetic field, sunspot numbers and cosmic ray activity may serve as a potential warning of future pandemics. Together with other epidemiological data such information might prove to be a useful factor for strategic disease control planning of YFV as well as other pandemic-causing viruses. References 1.Christopher F,NilsO,StavrosK,NicolasG,LarsT. Recent geomagnetic secular variation from Swarm and ground observatoriesas estimated in the CHAOS ‑ 6geomagneticfieldmodel. Earth, Planets and Space .2016;68:112 2.Pavón-Carrasco, F. Javier; De Santis, Angelo. The South Atlantic Anomaly: The Key for a Possible Geomagnetic Reversal.Frontiers in Earth Science.2016;4:40. 3.Pan,H, Liu,X. Apparent Biological Effect of Strong Magnetic Field on Mosquito Egg Hatching. Bioelectromagnetics,2004;25:84–91 4.Wickramasinghe NC, Steele E, Wainwright M, Tokoro G, Fernando M, Qu J. Sunspot Cycle Minima and Pandemics: The Casefor Vigilance? Astrobiol Outreach 2017 ； 5: 159. 5.World Data Center for Cosmic Rays (WDCCR) http://center.stelab.nagoya-u.ac.jp/WDCCR/allplot1sta.php?st=MEXICO 6.Qu J. Is sunspot activity a factor in influenza pandemics? Rev Med Virol . 2016;26 (5):309-313. 7.Qu J, Wickramasinghe C. Was the Zika virus Outbreak in 2015 Triggered by Cosmic Events?.VirolCurr Res2017;1:102. 8. Myrna C Bonaldo, MarielaMartínez Gómez, Alexandre AC dos SantosFilipe Vieira Santos de Abreu, Anielly Ferreira-de-Brito, RafaellaMoraes de Miranda, Marcia Gonçalves de Castro, Ricardo Lourenço-de-Oliveira. Genome analysis of yellow fever virus of the ongoing outbreak in Brazil reveals polymorphisms. Memórias do InstitutoOswaldo Cruz. 2017;112(6):447-451 Weakened geomagnetic field, Cosmic rays the Resurgence of Yellow Fever https://juniperpublishers.com/ijcsmb/IJCSMB.MS.ID.555636.php
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