A total of 13 tuberculosis infections have been confirmed to date in Déline, N.W.T., located about 540 kilometres northwest of Yellowknife on the southwestern shore of Great Bear Lake.

Four new cases of tuberculosis have been confirmed in Déline, N.W.T., where an outbreak sparked panic shortly before the holidays in 2009.

Northwest Territories health officials say the new infections were caused by a person who had TB during the last outbreak in November, but was not detected.

That person infected three others, bringing the total number of TB cases to 13 in the remote community of about 500.

In light of the new cases, health officials are screening everyone in Déline, then plan to treat everyone who tests positive for TB.

"We have screened about half the community to date for TB," Dr. Kami Kandola, the N.W.T.'s chief medical officer, told CBC News on Tuesday.

"People were lined up for two days to get screened, so there is an active interest to get screened."

Tuberculosis is a contagious airborne respiratory disease caused by the Mycobacterium tuberculosisgerm.

The initial TB outbreak raised concerns in Déline because it began before the Christmas holidays, when people travel and host holiday gatherings, potentially raising the risk of more infections.

In addition to the 13 TB infections, health officials say 47 others in Déline are carriers of the Mycobacterium tuberculosisgerm.

Those 47 cases are latent, meaning those people are not showing any symptoms and they cannot transmit the germ unless it develops into the full-blown disease.

People who do show symptoms of TB are generally hospitalized and quarantined for about two weeks.

Afterwards, they are not considered infectious and they can then be treated at home. Patients must take TB medication, under the supervision of health workers, for up to nine months.