Homeless men in Los Angeles in 2006. (Ted Soqui/Corbis)

Tuberculosis appears to be on the rise among Los Angeles County's vulnerable homeless population, prompting the county health department to seek federal help.

In the last five years, the county health department reported 78 people with the bacterial disease in or around the skid row neighborhood. Sixty of them were known to be homeless.

"It's a well-defined population and a relatively small geographic area with a difficult population to work with, so we're putting a concentrated effort into making sure these individuals who are already vulnerable are getting attention," Dr. Jonathan Fielding, who directs the LA County Department of Public Health, told ABCNews.com.

Fielding's department has called upon the Centers for Disease Control and Prevention and people who work in the homeless shelters to help identify and test people with tuberculosis symptoms, which include a cough that lasts more than three weeks, coughing up blood, weight loss, night sweats, fatigue and fever.

This particular strain of the disease is sensitive to drugs, so treatment is effective if the patient is able to get help and follow up with it, Fielding said. However, eight people who got the disease also had HIV, rendering their immune systems less able to fight it off. Of those, six died.

"It's a very bad combination, especially if it's not being adequately treated," Fielding said.

Fielding said 4,650 people frequent the local homeless shelters from time to time and could, therefore, have been exposed to tuberculosis. The disease is airborne, but not as contagious as the cold or flu. It spreads by "fairly close contact" with infected individuals over an "extended period of time," he said.

"You don't get tuberculosis from being next to someone or walking down the street," he said.