First, this is a very scary first step in the assault on privacy. It is an opening for people to argue that a person who fits a certain search profile should be de-anonymized. After all, wouldn't you want to know if you had cancer? In addition, as it is not about law enforcement but public health, there are a lot fewer limitations on what information the government can access.
Second, after seeing the type of queries, I do not think that this is all that helpful. If a person has unexplained weight loss or yellow skin or eyes, they should always go see their doctor right away. My guess is that most of the specificity of this study comes from those two terms (weight loss combined with yellow skin). Just getting out that message will do a lot more to save people's lives than violating their privacy in this manner.
Second, after seeing the type of queries, I do not think that this is all that helpful. If a person has unexplained weight loss or yellow skin or eyes, they should always go see their doctor right away. My guess is that most of the specificity of this study comes from those two terms (weight loss combined with yellow skin). Just getting out that message will do a lot more to save people's lives than violating their privacy in this manner.