Ready steady spit: A community based screening for lung tuberculosis amongst high-risk groups in Aalborg, Denmark

Abstract

Introduction: Spot sputum culture screening for TB amongst high-risk groups has proven a good method to catch infected individual in a less infective stage of the disease increasing the likelihood of achieving infection control. Only few studies investigating the prevalence of TB in high-risk groups have been performed in Denmark.

Aim: To investigate the prevalence of lung tuberculosis amongst high-risk groups in our setting.

Methods: On 4 occasions, from summer 2016 to spring 2019, a team of outreach nurses offered screening for lung tuberculosis to socially vulnerable individuals present at 17 locations in the municipality of Aalborg at the time of each visit. All spot sputum samples were further examined by microscopy, culture with genotyping, and nucleic acid amplification (PCR) at Statens Serum Institut, Denmark.

Results: In 230 individuals offered screening, 316 sputum samples were collected. In total 9 were diagnosed with pulmonary TB. Of those, 7 (77.8 %) were identified by the first spot sputum screening of each participant. This reveals a prevalence of 3043/100000. Of the total 9 TB cases, 4 (44.4 %) were smear-positive, and 100% culture-positive. PCR was performed, and were positive for TB in smear-positive samples. Chest x-ray examination was suggestive of TB in 8 out of 9 patients (88.9 %). All patients identified with TB started treatment, which was reported successful in 8 out of 9 patients, one patient was non-compliant and eventually died.

Conclusion: Prevalence of pulmonary TB was high and similar to comparable, previous studies. Half of the culture positive patients were initially smear-negative, suggestive of a less infective stage.