MetroAccess serves people who cannot travel on Metrobus and Metrorail.
The lawsuit indicates the unidentified driver had the disease while transporting MetroAccess riders for several months in 2008. When the problem was discovered, Metro officials sent a notice to all riders who had come in contact with the driver between April and October of that year.
Attorney for the group, David Wasser, says that effort fell short for a group of people who live with a variety of health and social issues.
"Many people didn't get the notices that were supplied by MetroAccess, so part of what we've been doing is contacting people by phone to really let them know to get tested," he says.
Wasser also says so far at least 3 of 700 potential plaintiffs have tested positive for exposure to tuberculosis. Officials from Metro and MV Transportation, contractor for MetroAccess, declined comment on the active litigation.