About 18 people are being treated for tuberculosis after testing positive for the disease during a scare last month caused by an infected man riding a Loudoun County commuter bus.

None of the new patients are demonstrating symptoms or are thought to have contracted the disease from a fellow rider, Loudoun County Health Director Dr. David Goodfriend said.

“There is no indication any one got sick on the bus,” he said.

Loudoun County offered free tuberculosis testing in August to 180 passengers after a daily commuter was diagnosed with the disease and suspected to have been contagious for three months earlier this year.

This story continues below
Advertisement

About 10 percent of the commuters tested positive, which Goodfriend attributed not to the fellow rider, but to prior exposure in other countries where TB is more common.

“For everybody who had a positive test, we recommend that they go on medication because they have 10 percent chance of getting sick at a later time,” he said.

Although the county reports an average of 16 tuberculosis cases each year, the commuter case is the first one this year in which the county has had such a large pool of people who could have been infected. If everyone in the county was tested, Goodfriend said, “It is likely that hundreds or thousands of people would test positive.”

The group of 180 riders will be invited for further tests in October to see whether any of the commuters who tested negative in August have since demonstrated symptoms, Goodfriend said.

dgenz@dcexaminer.com