[Contact Investigation in Active Tuberculosis and Management of Latent TB Infection: 5-year Analysis at a German City Health Authority].

BACKGROUND

As part of the German TB control program, health authorities conduct investigations among contacts of patients with active tuberculosis based on the infection prevention legislation, to identify potential infections among these persons. The aim of this study was to analyze retrospectively procedures of the city health authority Cologne, in cases of newly diagnosed latent TB infection (LTBI) over a 5-year period.

METHODS

Data from the Cologne City Health Authority on contact investigations of TB cases between July 1st 2012 und December 31st 2016 were analyzed. In the absence of signs for active TB and a positive result of the interferon gamma release assay (QFT), LTBI was diagnosed in contact persons. Those with positive test results aged 16 and above and registered in Cologne were included.

RESULTS

Out of 3859 contact persons, 430 met the inclusion criteria: in 174/430 cases chemo-preventive therapy (CPT) was recommended and 65 (35.1 %) actually took the course of CPT; in 117 cases, no records of CPT were found in the files and 22/430 persons with LTBI developed active TB within the observation period.

CONCLUSION

If the full potential of LTBI treatment on the basis of the recommendations of WHO's "End TB-Strategy" is to be realized, the present study reveals the need to continuously improve documentation and management of LTBI in this setting.