Jul 18, 2002 — Five Canadian workers at the Champlain border crossing, north of Plattsburgh, have been infected with tuberculosis. Officials say the source was a refugee, detained at the border for several days. As Brian Mann reports, dozens of travelers may have been exposed, but north country health officials say there's no cause for alarm. Update: A spokesman for the US Customs service says there've been no recent cases of TB exposure among American border agents. Mike McMullen says infectious diseases are a well-known hazard for workers at the border. Testing and vaccinations are offered regularly. According to McMullen, the recent case won't affect safety procedures at the Champlain crossing.