Risk factors for latent tuberculosis in children who had close contact to households with pulmonary tuberculosis

ABSTRACT

PURPOSE: Tuberculosis (TB) is a common and possibly fatal infectious disease, and its incidence and prevalence is quite high in Korea compared to other Organization for Economic Co-operation and Development countries. Patients who have active TB can cause latent tuberculosis infection (LTBI) in children, which may progress to reactivated tuberculosis. This study was performed to analyze the risk of adult TB that affects children's LTBI. METHODS: From June 2013 to May 2014, 60 children (32 boys, 28 girls) who came into close contact with adult patients diagnosed with pulmonary TB underwent LTBI tests. The children were divided into the 2 groups: the first group was finally diagnosed to LTBI, and the second group was proven not to have LTBI. We compared the risk of adult patients with pulmonary TB between children with LTBI and those without through a medical record review. RESULTS: The number of adult patients with TB was 36 (father 68%, mother 23%, grandparents 8%). The patients who came into close contact with the LTBI group were older (47.0±12.8 years vs. 41.3±6.6 years) and had higher erythrocyte sedimentation rate (ESR) levels than those of the second group. The rate of negative acid-fast-bacilli smear with positive culture results in patients who came into contact with the LBTI group was higher than in the second group. The cutoff value of ESR for the diagnosis of LTBI was 31 mm/hr with a sensitivity of 0.75 and a specificity of 0.85 (area under curve=0.748). CONCLUSION: Adult pulmonary TB patients who are older and have higher ESR levels may be risk factors for LTBI in children coming into close contact with them.