Public-health officials eventually joined the dots and identified her as a carrier of Salmonella typhi, the bacterium that causes the disease.

最终公共卫生部进行调查，并确定她是伤寒杆菌（一种会引起疾病的细菌）的携带者。

It's caused by the bacteria Salmonella typhi, and most of the time, it's passed from one person to the next through food or water that's been contaminated.

它是由伤寒沙门氏菌引起的，而且绝大多数情况下，它是通过被污染的食物或水从一个人传播到另一个人的。