Those are caused by a viral infection.

由引起。

So about three billion years ago, bacteria evolved a defense mechanism to fight viral infection.

所以大约30亿年前，细菌进化出一种防御机制来对抗。

And pneumonia, often triggered by bacterial or viral infections, attacks the alveoli themselves.

肺——常常由细菌或引发——会攻击肺泡本身。

Fever and muscle aches are common symptoms for a viral infection.

发烧和肌肉疼痛是常见症状。

The veterinarian said a viral infection caused the marmot's abnormal behavior.

兽医说，导致了土拨鼠异常行为。

Broadly speaking, the genes less active in the lonely were those involved in staving off viral infections.

一般来说，孤独人体内活力较低基因是那些帮助人们避开基因。

It's now semi-paralyzed, possibly due to a viral infection the wasp gave it.

瓢虫处于半麻痹状态，可能源自黄蜂造成。

It can be caused by a viral infection or just from yelling too much.

这可能是由引起，或者只是因为大喊大叫得太多了。

And die a slow, agonizing death From a viral infection than work with you.

抑或是上痛苦而挣扎着死掉也不要和你一起工作。

When the cause is identified, it's usually a viral infection, like Coxsackie B virus.

急性心已知因通常是，如柯萨奇B组。

Viral infection is triggered by a common parasite, the Varroa mite, that spreads rapidly in beehives.

传播是由一种常见寄生虫蜂虱引发，这种寄生虫能在蜂巢里很快传播开来。

Another clue is that an individual's response to viral and bacterial infections might be involved.

另外，个体对和细菌反应可能也牵涉其中。

The best way to prevent the spread of a viral infection is to have a vaccine.

预防传播最好方法就是接种疫苗。

Many had a higher than normal body temperature and what seemed like a common viral infection.

许多人体温高于正常体温，这似乎是一种常见。

It is an inflammatory problem that affects the spinal cord and is often started by viral infections.

这是一种影响脊髓症，通常是由引起。

In the early days, antibiotics were heavily overprescribed, including for viral infections they had no effect on.

早期，抗生素处方严重过量，甚至被用在毫无疗效上。

Measles is a viral infection that is serious for small children but is easily preventable by a vaccine.

麻疹是一种性传，这种传对幼儿来说很严重，但却很容易通过疫苗预防。

Hepatitis C is a serious viral infection that can cause liver damage and even liver cancer, if left untreated.

丙肝为性传性疾，若不及时治疗，它将对肝脏造成损坏，甚至引发肝癌。

Other events, like warming oceans and heat waves, spoil seafood and droughts bring bats carrying viral infections to people.

其他事件，如海洋变暖和热浪会使海鲜变质，干旱会把携带传蝙蝠带给人类。

When it happens after a viral infection, such as COVID, research shows symptoms go on for weeks and months.

而如果在新冠等后出现，研究显示症状会持续数周或数月。