A thoughtful point. However, with regards to TB, a healthy individual can be exposed to TB, be a carrier but not yet "infected" and, therefore not infect others (the immune system of a healthy person will surround the TB cell preventing it from multiplying until such time that individual's immune system fails). The problem with those who have active TB, is that they can infect many while the American visitor to Mexico, who may be exposed but is healthy, will return and not infect others. However, they have acquired a possible "ticking time bomb"... which may never activate. Unfortunately, there is now a form of TB that is resistant to drugs.
If anything, this article presents an even stronger argument for Bush's proposal... the more that people are documented as they come across our border, the more likely that illnesses or exposure to such will be screened properly.
Remember, this article was written before Bush laid out his proposal. It did not take that into account. The concern was immigrants, legal and not, entering the country without screening. In Bush's proposal, would screening taking place with documented immigrants/workers? I saw no mention of it.
I support a worker's program. My concern is screening. And I wish I had more information about just how valid the concern is. The statistics from both articles are pretty scary.