康复后,这些人群要小心二次感染******
目前很多新冠病毒感染者逐渐康复,然而,不少人担心,如果新冠病毒的毒株不同,是否会再次感染。为此,科技日报记者专访了中国工程院院士张伯礼,请他就新冠病毒二次感染的相关问题进行解答。
转阴后3—6个月内发生二次感染概率较低
“再次感染新冠病毒的概率主要与人体免疫水平、病毒株变异以及后期个人防护有关。”张伯礼说,相较于早期变异株,奥密克戎可能引发更多的突破性感染和重复感染。
不过张伯礼表示,大家也不用过于担心,虽然尚未有大样本人群证据显示奥密克戎变异病毒株感染后持续免疫的具体时间,但在新冠病毒感染后,人体免疫系统已在发挥作用。根据当前临床观察,感染后3—6个月内发生新冠病毒二次感染的概率还是比较低的。
与此同时,很多人担心二次感染新冠病毒会加重症状。对此,张伯礼表示,二次感染新冠病毒的症状与是否有基础疾病、病毒感染剂量以及个人身体状况等多种因素相关。但从目前多数报道来看,由于机体已产生免疫力,第二次感染的症状一般会较上次轻。
不过,他强调,也有少数研究报告显示,与仅感染过一次的患者相比,再次感染的患者出现并发症的风险更高,包括肺部、心血管、糖尿病、胃肠道和神经系统等并发症。
建议康复六个月后接种新冠疫苗
“虽然短时间再次感染相同新冠病毒变异株的可能性不大。但免疫力较差的人群容易反复感染,包括老年人、婴幼儿、有基础疾病的人群以及免疫缺陷人群,短期内存在二次感染的风险,特别是面对新的变异株时。”张伯礼介绍,医生、护士等高风险岗位的人群,所处工作环境传播风险高,接触变异毒株多,工作强度大,二次感染的风险较高。
“为了避免新冠病毒变异毒株的再次感染,转阴后也要继续做好个人防护。”张伯礼强调,“阳康”6个月后可以接种新冠疫苗,最好采用序贯策略,注射异种疫苗,以强化免疫屏障。
对于新冠病毒感染康复者而言,预防二次感染最好的办法仍是落实好防护措施,包括戴口罩、注意手卫生、注意休息、勤通风、保持社交距离等,特别是对老年人和儿童“阳转阴”患者,应当注意保暖,尽量少聚集,保证良好的卫生习惯,注意营养饮食,增强免疫力,尽量降低再次感染的风险。
如果出现再次感染,一定要首先分清“复阳”与二次感染。“复阳”发生在转阴后2—3周内,患者一般无明显临床症状,主要是体内残留病毒片段检测出的阳性,一般没有传染性;而二次感染一般发生在首次感染后数月至一年内,相当于一次新的感染,一般有临床症状出现,并且病毒核酸载量较高,具有传染性。
“‘复阳’患者一般无需再治疗,注意休息,合理膳食和营养即可。”张伯礼提醒,二次感染的患者需再次进行规范治疗,并严格做好个人防护,做好自我隔离,降低疫情传播的风险。(记者陈曦)
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() |