Outcomes of contact investigation among homeless persons with infectious tuberculosis

Homelessness is an important risk factor for tuberculosis (TB). Health departments often fail to identify contacts for homeless TB cases, but little else is known about the outcome of contact investigations for these cases.

To describe the outcomes of identification, tuberculin skin testing (TST), clinical evaluation and treatment for contacts of infectious homeless TB cases.

Retrospective multicenter review of data of contact investigations conducted in 1996 by five health departments in the United States.

Twenty-seven (8%) of 349 TB cases were homeless. Failure to identify contacts occurred in six (50%) of 12 cases residing in shelters vs. one (7%) of 15 non-shelter cases. Of 479 contacts identified, 297 (62%) were fully evaluated, 97 (20%) had only initial testing, and 85 (18%) were not evaluated. Of the 394 evaluated contacts, 13 (3%) had a prior positive TST. Of the remaining 381 contacts, six (1.6%) had active TB and 67 (17.6%) were TST-positive. Only 27 (44%) of 61 contacts completed treatment for latent TB infection.

Despite the failure to identify contacts for some cases, contact investigations for homeless TB cases identified large numbers of contacts for whom evaluation and treatment were often not completed. Prospective studies with more complete documentation are needed to improve contact investigations for homeless TB cases.