禽流感在亚洲持续扩散，引发全球卫生机构关切

While trying to avoid alarmism, global health agencies are steadily ratcheting up concern about bird flu in Asia. Bird viruses that can infect humans — particularly those of the H7N9 strain — continue to spread to new cities there.

在避免危言耸听的同时，全球卫生机构对亚洲禽流感的关切正在逐步加剧。能感染人类的禽流感病毒——尤其是H7N9——继续扩散至该地区的更多城市。

Since October 2016, China has seen a “fifth wave” of H7N9 infections. Nearly 1,600 people have tested positive, almost 40 percent of whom have died.

自2016年10月以来，中国正出现“第五轮”H7N9感染。近1600人检测呈阳性，其中近40%的人死亡。

Most had been exposed to live poultry, but a small number of clusters suggest that the virus could be passing from person to person.

这当中的大部分人曾经接触过活禽。但少数集聚的情况表明，这种病毒可能出现了人际传播。

In September, the Centers for Disease Control and Prevention summarized some disturbing developments. The H7N9 virus had become lethal to birds, which made it potentially more dangerous to people but also easier to spot.

9月，美国疾病控制和预防中心(Centers for Disease Control and Prevention)总结了一些令人不安的事态发展。H7N9病毒对鸟类来说是致命的，这使得它可能对人类更为危险，但也更容易被发现。

And the virus had split into two lineages — called Yangtze and Pearl, after the river deltas in which each was spreading — complicating efforts to make vaccines.

该病毒已经演化出两个分支，分别被称为长江和珠江，以它传播的两个三角洲命名。这给疫苗的制造增加了困难。

In October, the World Health Organization put out an update citing new cases of H7N9 infection as cold weather set in and noting that poultry farmers were vaccinating flocks against both this virus and other strains.

10月，世界卫生组织(World Health Organization)发布了最新报告，称随着天气转冷，出现了新的H7N9病毒感染病例，并指出，家禽饲养者正在给家禽注射这两种毒株以及其他毒株的疫苗。

At about the same time, a well-known virologist at the University of Wisconsin — Madison showed that a Chinese H7N9 strain could both kill ferrets and be transmitted between them.

与此同时，威斯康星大学麦迪逊分校(University of Wisconsin-Madison)的一位著名病毒学家发现，中国的H7N9毒株不仅能导致雪貂死亡，还可以在它们之间传播。

Because ferrets suffer roughly the same effects from flu that humans do, the development was “not good for public health,” said the virologist, Dr. Yoshihiro Kawaoka.

病毒学家河冈义裕博士(Yoshihiro Kawaoka)表示，禽流感对雪貂的影响与对人类的影响大致相同，它的发展“不利于公共卫生”。

Many microbiologists consider influenza to be the virus most likely to start a pandemic that kills millions, as the 1918 Spanish flu did. But the flu is notoriously unpredictable. Public health experts have become wary about raising alarms over new strains because the grave predictions made in 2005 and 2009 turned out to be overblown.

很多微生物学家认为，流感病毒是最可能引发数百万人死亡的流行病病毒，就像1918年的西班牙流感那样。不过，这种流感是出了名的不可预测。公共卫生专家在谨慎提高人们对新病毒类型的警觉，因为结果证明，2005年和2009的实际情况没有预测得那么严重。

In 2005, it was feared that the H5N1 avian flu, which killed or forced the culling of millions of chickens and ducks, would mutate and spread widely among humans.

2005年，人们担心H5N1型禽流感病毒会变异，并在人类中广泛传播。该病毒导致数百万鸡鸭死亡或被扑杀。

It still circulates, primarily in Egypt and Indonesia, but so far has not become a human epidemic. As of last month, only 860 people in 16 countries had tested positive for the infection. Still, more than half of them died.

H5N1仍在传播，主要是在埃及和印度尼西亚，但迄今为止，还没有变成人类流行病。截至上个月，16个国家中只有860人检测出感染阳性，但感染者中仍有半数以上的人死亡。

And in 2009, a new H1N1 flu virus containing genes from both American and Eurasian pigs emerged in Mexico, prompting scary “swine flu” headlines and the declaration of a health emergency.

2009年，一种带有美国和欧亚的猪基因的新型H1N1流感病毒在墨西哥出现，导致媒体开始大肆报道可怕的“猪流感”，并宣布进入卫生紧急状态。

That virus has now become one of the seasonal flu strains circling the world. It has infected millions but has killed relatively few people.

这种病毒现在已成为在世界各地传播的季节性流感病毒之一。已有数百万人感染该病毒，但死亡人数相对较少。

The 2017-2018 flu season in the United States does not yet seem unusually threatening. But Australia, where winter recently ended, just suffered one of its deadliest outbreaks in a decade, and the H3N2 and B Yamagata strains that dominated there are now the most common ones in the United States.

美国的2017年至2018年流感季似乎还不太危险。但是，冬季刚结束的澳大利亚刚刚经历了十年来最致命的一次疫情，该地区最常见的H3N2和B山形菌株现在是美国最常见的菌株。

Flu hospitalizations in this country rarely shoot up before mid-December, and Americans are far more likely than Australians to get flu shots.

在12月中旬之前，美国的流感住院人数很少激增，而且美国人注射流感疫苗的可能性比澳大利亚人大很多。