ABSTRACT
Even though some studies have reported the results of serial interferon-gamma release assays (IGRAs) during isoniazid prophylactic treatment, serial results have not been reported after rifampicin prophylaxis. A contact investigation was conducted after a tuberculosis (TB) outbreak in an accommodation facility. The tuberculin skin test (TST) and the QuantiFERON-TB Gold In-Tube (QFT-GIT) test were performed in 214 contacts with normal chest radiographs. Rifampicin prophylaxis was initiated in TST+/QFT-GIT+ subjects, and the QFT-GIT test was repeated upon completion of 4 months of rifampicin treatment. Among the 214 contacts, the TST and QFT-GIT test results were positive in 67.7% and 56.7%, respectively, and the agreement between the two tests was fair-to-good (78.3%, kappa=0.55, p<0.001). The QFT-GIT test was positive in 77% (97/126) of contacts with positive TST results. Rifampicin prophylaxis was completed in 81 subjects with good compliance. Among 74 subjects with valid serial QFT-GIT test results, IFN-gamma levels decreased in 97.3% (72/74) of the subjects and QFT-GIT test reversion (positive to negative) was achieved in 31 subjects (41.9%). Subjects without QFT-GIT test reversion had a significantly higher baseline TST induration sizes (18.3+/-4.8 vs. 14.9+/-3.4mm, p<0.01) and IFN-gamma levels (18.6+/-17.9 vs. 3.2+/-7.5IU/mL, p<0.01) than the subjects with QFT-GIT test reversion. Thus, IGRAs may be useful in evaluating the therapeutic response to rifampicin prophylaxis in TB contacts. However, considering that this was not a controlled study, a prospective controlled study is needed to determine whether rifampicin prophylaxis truly affects QFT-GIT reversion.
Subject(s)
Antitubercular Agents/therapeutic use , Interferon-gamma/immunology , Latent Tuberculosis , Rifampin/therapeutic use , Tuberculosis, Pulmonary , Adolescent , Adult , Aged , Disease Outbreaks , Female , Humans , Latent Tuberculosis/diagnosis , Latent Tuberculosis/drug therapy , Latent Tuberculosis/immunology , Male , Middle Aged , Republic of Korea , Tuberculin Test/methods , Tuberculosis, Pulmonary/diagnosis , Tuberculosis, Pulmonary/drug therapy , Tuberculosis, Pulmonary/immunology , Young AdultABSTRACT
The infection rate of Enterobius vermicularis was investigated in 1,191 preschool children in 25 daycare centers in Seoul, Korea by cellotape anal swab from July to August 1999. Both the directors of the daycare centers and the children's parents were asked to complete questionnaires that inquired about the potential risk factors involved. The overall egg positive rate for E. vermicularis was 9.5%, and the prevalence in the daycare centers ranged from 0 to 31.1%. Children aged 6-7 years showed a significantly higher egg positive rate than younger children, but the infection rate was similar for boys and girls. The socioeconomic status of the family and personal hygiene were not associated with enterobiasis, but anthelmintic medication significantly reduced the infection rate. The daycare centers in residential areas showed significantly lower egg positive rates than those situated near traditional markets. The environment of daycare centers is an important factor in enterobiasis, and the mass screening and treatment of children at high risk is recommended.