That said, Typhoid Mary is very well-written, even the dull bits. The research is well-documented and complete. And the subject matter is more than a little engrossing. Who was the woman behind the label "Typhoid Mary"?
Leavitt is making the link between typhoid and AIDS, in particular the problem of finding the balance between protecting individual rights and protecting the community. She spends time on this subject towards the end of the book and has some compassionate and reasonable things to say. The strongest part of the book, however, is in the history and in Leavitt's appreciation of Mary Mallon as an individual. The most interesting parts of the book (and where the writing picks up considerably) are the chapters on the public perception of Typhoid Mary throughout the 20th century.
Recommendation: Buy it if it's a subject that already interests you. Otherwise, check it out of the library.