These Coronavirus Exposures Might Be the Most Dangerous

疫情中我们最应警惕哪些病毒暴露?

纽约时报双语版-疫情中我们最应警惕哪些病毒暴露?

导致Covid-19的病毒的电子显微镜图像。
Image Point Fr – Lpn/BSIP — Universal Images Group, via Getty Images

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Li Wenliang, the doctor in China who raised early awareness of the new coronavirus, died of the virus in February at 34. His death was shocking not only because of his role in publicizing the developing epidemic but also — given that young people do not have a high risk of dying from Covid-19 — because of his age.

2月因新冠病毒去世、卒年34岁的李文亮医生,是中国较早意识到该病毒的人。他的去世令人震惊,不仅是因为他在公开流行病蔓延消息中起的作用,还因为他的年龄——Covid-19在年轻人中的死亡风险并不高。

Is it possible that Dr. Li died because as a doctor who spent a lot of time around severely ill Covid-19 patients, he was infected with such a high dose? After all, though he was one of the first young health care workers to die after being exposed up close and frequently to the virus, he was unfortunately not the last.

李文亮医生是否可能因为经常接触Covid-19重症患者,导致感染高剂量病毒而死亡?毕竟,他虽然是第一批近距离频繁暴露于病毒后去世的年轻医务人员之一,但不幸的是,他并不是最后一个。

The importance of viral dose is being overlooked in discussions of the coronavirus. As with any other poison, viruses are usually more dangerous in larger amounts. Small initial exposures tend to lead to mild or asymptomatic infections, while larger doses can be lethal.

在新冠病毒的讨论中,病毒量的重要性被忽略了。与其他任何有害物一样,病毒通常是量越多越危险。起初的少量病毒暴露会导致轻度或无症状感染,而较大的量可能会致命。

From a policy perspective, we need to consider that not all exposures to the coronavirus may be the same. Stepping into an office building that once had someone with the coronavirus in it is not as dangerous as sitting next to that infected person for an hourlong train commute.

从政策角度来看,我们需要考虑到并非所有新冠病毒的暴露都是一样的。走进曾经有新冠病毒携带者的办公楼,比起邻座坐着同一个感染者的一小时火车路程,前者没有后者那么危险。

This may seem obvious, but many people are not making this distinction. We need to focus more on preventing high-dose infection.

这似乎看起来很明显,但许多人并未对此加以区分。我们需要更多地关注对高剂量感染的预防。

Both small and large amounts of virus can replicate within our cells and cause severe disease in vulnerable individuals such as the immunocompromised. In healthy people, however, immune systems respond as soon as they sense a virus growing inside. Recovery depends on which wins the race: viral spread or immune activation.

少量和大量的病毒都可以在我们的细胞内复制,并在如免疫力低下的易感人群中引发重症。然而,对于健康人,当免疫力系统觉察到病毒在繁殖时就会做出反应。恢复取决于哪一方赢得比赛:病毒传播还是免疫激活。

Virus experts know that viral dose affects illness severity. In the lab, mice receiving a low dose of virus clear it and recover, while the same virus at a higher dose kills them. Dose sensitivity has been observed for every common acute viral infection that has been studied in lab animals, including coronaviruses.

病毒专家知道病毒量会影响疾病的严重程度。在实验室中,接受低量病毒的小鼠会清除病毒并恢复原状,而较高量的相同病毒则会致死。在实验室动物中,每种常见的急性病毒传染病都可观察到剂量敏感性,包括冠状病毒。

Humans also exhibit sensitivity to viral dose. Volunteers have allowed themselves to be exposed to low or high doses of relatively benign viruses causing colds or diarrhea. Those receiving the low doses have rarely developed visible signs of infection, while high doses have typically led to infections and more severe symptoms.

人类也表现出对病毒剂量的敏感性。志愿者让自己暴露在低剂量或高剂量的相对良性的病毒下,这些病毒会引发感冒或腹泻。接收低剂量的人极少出现明显的感染迹象,而高剂量通常会导致感染和更严重的症状。

It would be unethical to experimentally manipulate viral dose in humans for a pathogen as serious as the coronavirus, but there is evidence that dose also matters for the human coronavirus. During the 2003 SARS coronavirus outbreak in Hong Kong, for instance, one patient infected many others living in the same complex of apartment buildings, resulting in 19 dead. The spread of infection is thought to have been caused by airborne viral particles that were blown throughout the complex from the initial patient’s apartment unit. As a result of greater viral exposure, neighbors who lived in the same building were not only more frequently infected but also more likely to die. By contrast, more distant neighbors, even when infected, suffered less.

对于像新冠病毒一样严重的病原体,进行控制病毒量的人类实验是有悖伦理的,但是有证据表明冠状病毒剂量对人类也很重要。例如,在2003年香港爆发SARS冠状病毒期间,一名患者感染了住在同一栋公寓楼内的许多人,导致19人死亡。感染的传播被认为是从最初携带者的公寓通过空气传播至整栋楼导致的。由于暴露在越来越多的病毒中,居住在同一建筑物内的邻居不仅受到感染的频率更高,而且更有可能死亡。相比之下,更远的邻居即使受到感染,遭受的损害也较小。

Low-dose infections can even engender immunity, protecting against high-dose exposures in the future. Before the invention of vaccines, doctors often intentionally infected healthy individuals with fluid from smallpox pustules. The resulting low-dose infections were unpleasant but generally survivable, and they prevented worse incidents of disease when those individuals were later exposed to smallpox in uncontrolled amounts.

低剂量感染甚至可以形成免疫,防止将来受到高剂量感染。在发明疫苗之前,医生经常故意使用天花脓疱的液体感染健康的个体。由此产生的低剂量感染虽然令人不适,但通常是非致命的,当这些人后来暴露于不受控制的天花剂量时,它们可以防止疾病的恶化。

Despite the evidence for the importance of viral dose, many of the epidemiological models being used to inform policy during this pandemic ignore it. This is a mistake.

尽管有证据表明病毒剂量很重要,但在疫情期间被用于指导政策的许多流行病学模型都忽略了它。这是不对的。

People should take particular care against high-dose exposures, which are most likely to occur in close in-person interactions — such as coffee meetings, crowded bars and quiet time in a room with Grandma — and from touching our faces after getting substantial amounts of virus on our hands. In-person interactions are more dangerous in enclosed spaces and at short distances, with dose escalating with exposure time. For transient interactions that violate the rule of maintaining six feet between you and others, such as paying a cashier at the grocery store, keep them brief — aim for “within six feet, only six seconds.”

人们应该格外小心高剂量暴露,这种暴露最有可能发生在面对面的亲密互动中——例如咖啡会议、拥挤的酒吧、与祖母安静地同处一室时——以及手上沾染大量病毒后不要用手摸脸。在封闭空间内和短距离内,面对面的互动会更加危险,并且病毒量会随着暴露时间的延长而增加。对于违反了六英尺距离规则的短暂交互,例如在杂货店付钱给收银员,请尽量迅速——力争“在六英尺内,仅六秒钟”。

Because dose matters, medical personnel face an extreme risk, since they deal with the sickest, highest-viral-load patients. We must prioritize protective gear for them.

由于剂量很重要,医务人员因为要治疗病情最重、病毒载量最高的患者,面临着极大的风险。我们必须让他们优先使用防护装备。

For everyone else, the importance of social distancing, mask-wearing and good hygiene is only greater, since these practices not only decrease infectious spread but also tend to decrease dose and thus the lethalness of infections that do occur. While preventing viral spread is a societal good, avoiding high-dose infections is a personal imperative, even for young healthy people.

对于其他每个人来说,保持社交距离、戴口罩和保持良好卫生才更加重要,因为这些做法不仅会减少传染性传播,而且还会减少病毒量,即使感染发生,也会因此降低感染的致死性。预防病毒传播对社会是好的,即使对于年轻健康的人,避免高剂量感染也是个人的当务之急。

At the same time, we need to avoid a panicked overreaction to low-dose exposures. Clothing and food packaging that have been exposed to someone with the virus seem to present a low risk. Healthy people who are together in the grocery store or workplace experience a tolerable risk — so long as they take precautions like wearing surgical masks and spacing themselves out.

同时,我们需要避免对低病毒量暴露引起惊慌的过度反应。被暴露于病毒携带者的衣物和食品包装似乎风险很低。对于杂货店或工作场所中的健康人来说,只要采取预防措施,如戴上外科口罩以及保持间距,风险是可以接受的。

A complete lockdown of society is the most effective way to stop spread of the virus, but it is costly both economically and psychologically. When society eventually reopens, risk-reduction measures like maintaining personal space and practicing proper hand-washing will be essential to reducing high-dose infections. High-risk sites for high-dose exposure, like stadiums and convention venues, should remain shuttered. Risky but essential services like public transportation should be allowed to operate — but people must follow safety measures such as wearing masks, maintaining physical spacing and never commuting with a fever.

将社会完全封锁是阻止病毒传播的最有效的方法,但无论从经济和心理上来讲,代价都是高昂的。当社会最终重新开放时,降低风险的措施——如保持间距和恰当的洗手——对于减少大剂量感染至关重要。暴露高剂量病毒的高风险场所,例如体育场馆和会议场所,应继续保持关闭状态。基础服务如公共交通,即使有风险,也应该允许运营——但人们必须遵守安全措施,例如戴口罩,保持间距以及不要在发烧期间上班。

Now is the time to stay home. But hopefully this time will be brief. When we do begin to leave our homes again, let’s do it wisely, in light of the importance of viral dose.

现在应该待在家里。但是这种状况有望在短时间内结束。考虑到病毒量的重要性,当我们再次开始走出家门时,请明智而为。