Is systematic screening and treatment for latent tuberculosis infection in HIV patients useful in a low endemic setting?

OBJECTIVES

A decreasing incidence of tuberculosis (TB) among HIV patients has been documented in high-income settings and screening for tuberculosis is not systematically performed in many clinics (such as ours). Our objectives are to evaluate whether a same decline of incidence was seen in our Belgian tertiary center and to evaluate whether systematic screening and prophylaxis of tuberculosis should remain part of routine practice.

METHODS

Between 2005 and 2012, the annual incidence of tuberculosis among adult HIV patients was measured. The impact of demographic characteristics and CD nadir on the incidence of active TB was evaluated.

RESULTS

Among the 1167 patients who entered the cohort, 42 developed active TB with a significant decrease of annual incidence from 28/1000 patient-years in 2005 to 3/1000 patient-years in 2012. Among the 42 cases, 83% were of sub-Saharan origin. Median CD4 cell count upon HIV diagnosis was significantly lower in TB cases and 60% had a nadir CD4 below 200/μl. Thirty-six percent of incident TB occurred within 14 days after HIV diagnosis.

CONCLUSION

A significant decline of TB incidence in HIV patients was observed. Incident TB occurred mainly in African patients, with low CD4 upon HIV diagnosis. A significant proportion of TB cases were discovered early in follow-up which probably reflects TB already present upon HIV diagnosis. In a low endemic setting, exclusion of active TB upon HIV diagnosis remains a priority and screening for LTBI should focus on HIV patients from high risk groups such as migrants from endemic regions, especially in patients with low CD4 nadir.