The authors argue the version of the disease that caused the medieval plague is likely extinct, but suggest that further study could reveal how it may have evolved into a less virulent strain.

作者们称引起中世纪瘟疫的品种可能已经灭绝了，但是他们认为进一步的研究可以揭示它是如何进化到一种没那么致命的类型。

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Fortunately, the strain was far less virulent than originally feared, killing about 19,000 people.

幸运的是，这种菌株的毒性远远小于人们原先所担心的，但也造成了约19,000人死亡。

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