Human activity has led to an increase in mosquito and tick-borne infections over the past decade.

在过去十年里，人类活动导致了蚊子和蜱虫传播感染风险增加。

Lyme disease is contracted from tick bites, and ticks are found outdoors, fitting the patient's history.

莱姆是由蜱叮咬感染，蜱多见于户外，符合患者旅游史。

But it finds its way to humans when infected ticks casually latch on to them in wooded areas.

但是在树木繁区，被感染蜱虫就会找到通往人类路。

The diagnosis: chronic Lyme disease, a tick-borne bacterial infection.

慢性莱姆, 蜱传播细菌感染。

The CDC reported this week that an estimated 300,000 Americans get the tick-borne disease every year.

疾预防控制中心本周报，计每年有 300,000 名美国人感染蜱传疾。

We might not know we have it, like a virus or tick infection or mold we're exposed to.

我们可能不知道自己已经感染了，比如毒、蜱虫感染或霉菌暴露。

Doctors would also check if patients were recently exposed to infected tick areas like forests or urban parks with exuberant vegetation.

医生还会检查患者是否最近接触过被感染蜱虫区域，比如森林或植被盛城市公园。

Better established is Lyme disease, caused by a spirochete that we get from the bite of ticks carried by mice and deer.

比较确定是莱姆，它是由老鼠和鹿携带蜱虫叮咬后感染螺旋体引起。

(bright music) Impalas living in between African woodlands and Savannahs are prone to catching ticks, which can lead to infectious diseases, paralysis, even death.

（明亮音乐）生活在非洲林和大草原之间黑斑羚很容易感染蜱虫，这会导致传染、瘫痪，甚至死亡。

RICHARD OSTFELD: What we found is that the probability that a tick is gonna acquire an infection when it feeds on a white-footed mouse is about 90 percent.

理查德·奥斯费尔德：我们发现，当鹿鼠被蜱虫叮咬时，蜱虫感染概率约为90%。