如何判断自己是复阳还是二次感染?感染过奥密克戎的人群对XBB、BQ.1是否还有保护力?******
近期,有关新冠复阳、二次感染的话题引起网友热议,有些网友对此存在忧虑情绪。上海中医药大学附属龙华医院肺病科主任医师薛鸿浩对相关问题作出回答。
薛鸿浩解释,复阳是指感染者体内残存的病毒延迟性排出,这些病毒来源于第一次病毒感染;而二次感染是第一次感染康复后被另外一个来源的新冠病毒感染,这些病毒来源于外部感染。一般复阳都是发生在康复之后一个月内,通过核酸PCR检出病毒片段。如果已经超过一个月,核酸又呈阳性,则再感染的可能性比较大,二次感染相隔时间比较久,一般要几个月。
据介绍,复阳与二次感染之间症状也存在区别:复阳阶段症状都已经恢复好转,不需要医学上的治疗干预,病毒核酸处于偶尔能检出的状态。因为抗原的灵敏性比核酸低,用抗原检测试剂可能就检不出来。但是二次感染则不同,病毒会经历一个完整的感染周期,包括病毒载量上升、平台维持、下降和消失,因此二次感染病毒浓度会很高,抗原就能连续性被检出,通常会是非常明显的两条杠,也会有不舒服的症状。
薛鸿浩说,如果要简单区别是复阳或是二次感染,可通过使用抗原检测试剂。在彻底康复一周或两周后,如果怀疑二次感染,可用抗原剂连续检测三天。如果检测结果是阳性,则可能是二次感染。复阳一般很难检出残余的病毒片段,就算偶尔被检出,一般也不会是一直连续的阳性结果。
那么什么样的人群容易出现复阳或二次感染呢?薛鸿浩表示,在免疫功能正常的人群里,发生复阳或者二次感染的概率都是很低的。一般免疫功能正常的患者感染康复之后,可以获得3到6个月以上的保护力。在这段时间内发生二次感染的概率也非常低,只有当免疫保护力变低时才可能发生二次感染。如果是新的病毒变异株,变异株可以打破第一次感染形成的免疫保护,就容易发生二次感染。
此外,也有市民关心,不同毒株是否会造成重复感染或是更容易复阳?目前来看在我国还是以BA.5.2、BF.7为主,BQ.1和XBB尚未形成优势传播,但其传播优势会逐渐增加,和BA.5.2和BF.7以及其他50多个输入的亚分支,可能会形成一个共循环。XBB.1.5 的感染者ACE2结合亲和力几乎与 BA.2.75 相当,可能使 XBB.1.5未来像BA.2.75一样获得更多突变,不过XBB.1.5目前免疫压力不大,还不会很快进化。
薛鸿浩介绍,如果遇到这几种毒株,再次感染的概率主要取决于两方面:一方面是再次遇到的毒株与BA.5和BF.7有多少重叠,如果病毒一直变异,交叉保护作用降低了则可能造成感染;另一方面则是看人自身抗体水平,尽管感染新冠后短时间内比如三到四个月内不会感染,但不可否认的是,新毒株流行或缩短二次感染“安全窗口”,接种疫苗仍然是最主要的预防手段。
据了解,对于复阳和二次感染,中医药学说中也有对应理论可供参考。伏邪理论始源于《素问.生气通天论》中“冬伤于寒,春必温病”的论述,是指在冬天伤于寒邪,内有正气不足,在春天发为温病,与新冠二次感染的概念比较相像;《伤寒论中》又有“伤寒感复”的说法,瘥后伏热未尽,复感新邪,其病复作;中医学中也有“劳复”“房劳”“食复”的描述,提示阳康后的患者应当注意饮食作息以防疾病的复发。
薛鸿浩指出,中医药理论中伏邪、感复的理论与复阳、二次感染存在相符合或重叠之处,尤其在发病的认识上一者注重机体免疫力,一者注重人体正气,在提高人体对病毒的抵抗力层面上基本一致。且中医药在治疗及预防新冠上也有独到之处,日常生活锻炼、饮食作息是中医着重的部分,如平时要注意防寒保暖、清淡饮食、作息规律,保持平和心态、不要太过焦虑;要加强运动,可以通过八段锦、六字诀、太极拳等中国传统功法适度锻炼,增强体质,提高免疫力;还可通过中药或食疗调理身体的阴阳平衡,从而提高免疫功能,防治病毒。如体质偏气虚的成年人尤其老年人可适当服用西洋参、黄芪等,脾虚湿重体质者可服用薏米等健脾化湿的中药或食品。(记者 郜阳)
中新网评:处理核污水绝不是日本自家私事******
中新网北京1月19日电(蒋鲤)日本政府近日称,将于2023年春夏期间开始向海洋排放经过处理的福岛第一核电站核污水。日本罔顾国内民众及周边国家的屡屡反对,企图将核污水“一倒了之”,把一件关乎全球海洋生态环境和公众健康的事当成了自家私事。
资料图:日本福岛第一核电站。2011年,福岛核电站事故发生后,大量放射性物质泄漏到大气层和太平洋,对周围环境造成了难以逆转的伤害,数十万人被迫撤离该地区。时至今日,作为日本邻国之一的韩国仍未解除福岛海鲜禁令。
日本以核污水存储能力即将达到上限为由,在2021年4月13日,正式决定将福岛第一核电站核污水排入太平洋。过去一年多,日本政府和东京电力公司一直在持续推进核污水排海计划。
日本政府辩称,这些核污水经多核素处理系统(ALPS)处理后很安全,甚至“可以喝”,这样的表态无疑在愚弄大众。
事实上,经过处理的核污水仍含有多种放射性物质,核污水一旦排放入海就无法回收,长期来看,将会给海洋生态带来难以估量的潜在威胁,最终危害人类健康。
因此,核污水排海计划推出后,遭到日本民众强烈反对。日本《朝日新闻》2022年3月公布的问卷调查显示,福岛县、宫城县和岩手县受访的42个市町村长中,约六成反对东京电力公司福岛第一核电站核污水排放入海。日本全国渔业协会联合会也多次申明立场,反对该计划。
日本政府认为,核污水排海是最便宜、最省事的解决方案,但此举却将周边国家乃至全世界置于核污染风险中。太平洋非日本一家之海,核污水会随着洋流流动,其影响势必会跨越国界,危害周边国家乃至整个国际社会的公共福祉和利益。
《韩国经济新闻》发文称,相关研究认为,福岛核污水如果排放入海,约7个月后将到达济州等韩国海域,该国水产业和旅游业将遭受相当大的损失。
德国南极海洋机构也曾发出警告,若日本将所有核污水排入海中,不到半年,整个太平洋都将面临高度辐射威胁,包括远在大洋另一端的美国。太平洋地区人民更是对日本该计划持反对意见。
日本作为《联合国海洋法公约》缔约国,有义务保护海洋环境。然而,在核污水排海方案的正当性、核污水数据的可靠性、净化装置的有效性、环境影响的不确定性等问题上,日本未能作出科学、可信的说明。
国际原子能机构技术工作组虽已三次赴日实地考察评估,但尚未就日排海方案的安全性给出结论,并且对日本提出诸多澄清要求和整改意见。在此情况下,日本仍执意推进核污水排海工程建设,这是极不负责任的行为。
太平洋不是日本的下水道,日本必须正视各方合理关切,在与周边国家等相关利益方和国际原子能机构充分协商后,制定合理的核污水处理方案。日本也要着眼长远,若只顾眼前,执意将核污水排放入海,不仅其自身,周边国家乃至全世界都将为之买单,其后果必将会危害数代人。
Fukushima water disposal by no means Japan’s own business
By John Lee
(ECNS) -- Japan has announced it will release treated wastewater from the wrecked Fukushima Daiichi Nuclear Power Plant into the Pacific Ocean this year.
Although Fukushima wastewater disposal affects global marine ecological environment protection and public health, Japan has turned a deaf ear to domestic and international opposition to dumping the contaminated water into the sea, treating the "global" matter as its own business.
The Fukushima accident in 2011 had sent large quantities of radiation into the atmosphere and the Pacific Ocean, causing irreversible damage to the surrounding environment, and hundreds of thousands of people were forced to evacuate the area. South Korea still maintains its import ban on Japanese seafood from areas affected by the Fukushima nuclear disaster.
On April 13, 2021, Japan announced it had decided to discharge contaminated radioactive wastewater in Fukushima Prefecture into the sea due to dwindling storage space, with the Japanese government and plant operator Tokyo Electric Power Company Holdings Inc. promoting the release plan over the past year.
The Japanese government argues that the water treated by an advanced liquid processing system, or ALPS, is safe and drinkable, which is undoubtedly fooling the public.
In fact, the treated wastewater still includes a variety of radioactive substances and can’t be recycled once discharged into the sea, which will pose a great threat to marine ecology and ultimately endanger human health in the long run.
Therefore, the discharge plan has been strongly opposed in Japan. According to a questionnaire conducted by The Asahi Shimbun, nearly 60 percent of mayors of 42 municipalities in Iwate, Miyagi and Fukushima prefectures oppose the discharge plan. The National Fisheries Cooperative Federation of Japan has also repeatedly stated its opposition in public.
The Japanese government believes that dumping Fukushima wastewater into the sea is the cheapest and most convenient solution, but neighboring countries and even the whole world will be at risk of nuclear pollution.
The Pacific Ocean doesn’t belong to Japan and the wastewater flow along oceanic currents will surely break boundaries and endanger public welfare and the interests of neighboring countries and even the international community.
The Korea Economic Daily reported that related research concluded that if contaminated water from Fukushima is released into the ocean, it would only take seven months for the contaminated water to reach the shores of Jeju Island, with the country's aquaculture and tourism suffering considerable losses.
According to the calculation of a German marine scientific research institute, radioactive materials will spread to most of the Pacific Ocean within half a year from the date of discharge, and the U.S. and Canada will be affected by nuclear pollution. People in the Pacific region also oppose the discharge plan.
As a participant of the United Nations Convention on the Law of the Sea, Japan has the obligation of protecting the marine environment.
However, it hasn’t offered a full and convincing explanation on issues like the legitimacy of the discharge plan, the reliability of data on the nuclear-contaminated water, the efficacy of the treatment system or the uncertainty of environmental impact.
Though the IAEA has yet to complete a comprehensive review after three investigations in Japan, the Japanese side has been pushing through the approval process for its discharge plan and even started building facilities for the discharge. It is rather irresponsible for Japan to act against public opinion at home and concerns abroad.
The Pacific Ocean is not a private Japanese sewer. The country must seriously heed the voices of the international community and make a reasonable plan for the Fukushima wastewater disposal after full consultation with stakeholders and international agencies.
If it only seeks instant interest and insists on discharging the contaminated water into the sea, not only itself, but also its neighboring countries and the entire world will pay for the decision and several generations will be forced to bear the consequence.
(文图:赵筱尘 巫邓炎) [责编:天天中] 阅读剩余全文() |