Survey of Secondary Infections within the Households of Newly Diagnosed Tuberculosis Patients

Abstract

Purpose:The purpose of this study is to investigate secondary infections within the households of newly diagnosed tuberculosis patients. Methods: We collected data on household infections of tuberculosis patients by retrospective review of medical records and telephone surveys. Results: Out of 321 newly diagnosed tuberculosis cases, a total of 253 patients who received telephone surveys were enrolled in this study. Less than 50% of the patients had household contacts screened for tuberculosis infection, and most of the patients were not aware of the necessity of testing. Out of 562 household contacts, there were 8 cases of secondary tuberculosis (1.4%, 8/562) in 7 households. There were 15 cases of latent infection (2.7%, 15/562) in 13 households. Out of 110 child and adolescent household contacts, there were no cases of secondary tuberculosis, and there were 8 cases of latent infection (7.3%) in 7 households, which was 20.5% among child and adolescent contacts screened for tuberculosis infection. In 3 of the cases (13.0%) that had secondary tuberculosis or latent infection in their households, the source of infection was extrapulmonary tuberculosis. There was no correlation between the frequency of household infections and the presence of pulmonary cavities, sputum AFB smear results, and microbiologically confirmed results. Conclusions: For effective investigation of tuberculosis contacts, it is necessary to raise general awareness on the necessity of investigating household contacts, and there should also be a continued assessment on tuberculosis contact investigation since government-supported programs.

The risk of active tuberculosis among individuals living in tuberculosis-affected households in the Republic of Korea, 2015

“…The treatment completion rate was lower than the equivalent in the United States (58%) and much lower than the equivalent in Japan, where reporting of LTBI is mandatory, and where treatment completion is estimated at 71.9% [21,22]. The low rate in our study might be due to low awareness of the importance of TB contact examination and treatment even among contacts that understand they had been exposed to TB [11]. Another possible explanation for these findings might be that the national policy at the time, required examination or treatment only of household contacts that were under-35 years of age or high-risk of TB [14].…”