Factors Associated with Loss to Follow-up during Treatment for Multidrug-Resistant Tuberculosis, the Philippines, 2012-2014.

To identify factors associated with loss to follow-up during treatment for multidrug-resistant (MDR) tuberculosis (TB) in the Philippines, we conducted a case-control study of adult patients who began receiving treatment for rifampin-resistant TB during July 1-December 31, 2012. Among 91 case-patients (those lost to follow-up) and 182 control-patients (those who adhered to treatment), independent factors associated with loss to follow-up included patients' higher self-rating of the severity of vomiting as an adverse drug reaction and alcohol abuse. Protective factors included receiving any type of assistance from the TB program, better TB knowledge, and higher levels of trust in and support from physicians and nurses. These results provide insights for designing interventions aimed at reducing patient loss to follow-up during treatment for MDR TB.

Chest radiographic findings in primary pulmonary tuberculosis: observations from high school outbreaks.

OBJECTIVE: To describe the radiographic findings of primary pulmonary tuberculosis (TB) in previously healthy adolescent patients. MATERIALS AND METHODS: The Institutional Review Board approved this retrospective study, with a waiver of informed consent from the patients. TB outbreaks occurred in 15 senior high schools and chest radiographs from 58 students with identical strains of TB were analyzed by restriction fragment length polymorphism analysis by two independent observers. Lesions of nodule(s), consolidation, or cavitation in the upper lung zones were classified as typical TB. Mediastinal lymph node enlargement; lesions of nodule(s), consolidation, or cavitation in lower lung zones; or pleural effusion were classified as atypical TB. Inter-observer agreement for the presence of each radiographic finding was examined by kappa statistics. RESULTS: Of 58 patients, three (5%) had normal chest radiographs. Cavitary lesions were present in 25 (45%) of 55 students. Lesions with upper lung zone predominance were observed in 27 (49%) patients, whereas lower lung zone predominance was noted in 18 (33%) patients. The remaining 10 (18%) patients had lesions in both upper and lower lung zones. Pleural effusion was not observed in any patient, nor was the mediastinal lymph node enlargement. Hilar lymph node enlargement was seen in only one (2%) patient. Overall, 37 (67%) students had the typical form of TB, whereas 18 (33%) had TB lesions of the atypical form. CONCLUSION: The most common radiographic findings in primary pulmonary TB by recent infection in previously healthy adolescents are upper lung lesions, which were thought to be radiographic findings of reactivation pulmonary TB by remote infection.

Serial interferon-gamma release assays after rifampicin prophylaxis in a tuberculosis outbreak.

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.

Spread of nontuberculous mycobacteria from 1993 to 2006 in Koreans.

In Korea, the prevalence of nontuberculous mycobacterial (NTM) pulmonary disease has risen, observed primarily in immunocompetent patients with or without preexisting lung disease. The purpose of this study was to determine the frequency of various species of NTM isolates from respiratory specimens in a single institution over a 14-year period in Korea. All samples referred to our reference laboratory over a 14-year period in Korea were analyzed. From 1993 to 2000 our laboratory used conventional NTM identification methods, and from 2001 we adapted PCR-restriction fragment length polymorphism analysis(PRA). A total of 17,915 isolates were collected from 1993 to 2006. The most frequently isolated organisms were M. avium complex (n=11,705, 65%), M. abscessus (n=2,076, 11.59%), M. fortuitum complex (n=1,279, 7.14%). M. chelonae complex (n=1,134, 6.33%), M. kansasii (n=762, 4.25%), M. szulgai (n=139, 0.78%), M. celatum (n=87, 0.49%), M. scrofulaceum (n=18, 0.10%) and M. marium (n=11, 0.06%).

In vitro antimicrobial susceptibility of Mycobacterium abscessus in Korea.

Mycobacterium abscessus is the second most common etiology of pulmonary disease caused by nontuberculous mycobacteria in Korea. Although antimicrobial susceptibility tests are important for appropriate patient management in M. abscessus lung disease, the tests have never been investigated in Korea. Seventy-four isolates of M. abscessus recovered from patient respiratory samples were tested against eight antimicrobial agents following the guidelines set forth by the National Committee for Clinical Laboratory Standards. Of the parenteral antibiotics, amikacin (99%, 73/74) and cefoxitin (99%, 73/74) were active against most isolates. Imipenem (55%, 36/66) and tobramycin (36%, 27/74) had activity against moderate number of isolates. Of the oral antibiotics, clarithromycin (91%, 67/74) was active against the majority of isolates. Moxifloxacin (73%, 54/74) and ciprofloxacin (57%, 42/74) had activity against a moderate number of isolates. Doxycycline was the least active, inhibiting only 7% (5/74) of isolates. In conclusion, the variations in susceptibility within M. abscessus isolates to currently available antimicrobials suggest that the antimicrobial susceptibilities of any clinically significant M. abscessus isolate be needed individually.

Mycobacterium kansasii pulmonary diseases in Korea.

Mycobacterium kansasii is one of the most common cause of pulmonary diseases due to nontuberculous mycobacteria. We investigated the changing in the number of isolation of M. kansasii and the clinical characteristics of M. kansasii pulmonary disease in Korea. Through searching the database of the Korean Institute of Tuberculosis, we identified the cases of isolated M. kansasii from 1992 to 2002. The number of M. kansasii isolation had increased from once in 1992 to 62 in 2002. Fifteen patients with M. kansasii pulmonary disease were identified during the period January 1997 to December 2002. Twelve patients (80%) were male and fourteen (93%) were from highly industrialized areas. The most common symptom was a cough. Seven patients (47%) had a cavitary lesion and right upper lobe was most commonly involved. Patients responded well to isoniazid and rifampicin based regimens both bacteriologically and radiographically. In conclusion, M. kansasii isolation has increased, especially in highly industrialized areas, as well as other nontuberculous mycobacteria in Korea.

Prevalence of chronic obstructive pulmonary disease in Korea: a population-based spirometry survey.

RATIONALE: Although chronic obstructive pulmonary disease is a leading cause of mortality and morbidity worldwide, there are only limited data on its prevalence, especially in Asia. OBJECTIVES: A population-based epidemiologic survey of chronic obstructive pulmonary disease in a representative national sample was conducted using spirometry. METHODS: A stratified multistage clustered probability design was used to select a nationally representative sample. The survey was performed in conjunction with the second Korean National Health and Nutrition Examination Survey of 9,243 adults over the age of 18 years. The participation rate was 88.8% for questionnaires and 52.1% for spirometry. RESULTS: The prevalence of chronic obstructive pulmonary disease based on Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria (a ratio of FEV1 to FVC of less than 0.7) was 17.2% (men, 25.8%; women, 9.6%) among subjects older than 45 years. Among adults of all ages (age>18 years), the prevalence of airflow obstruction was 7.8% (10.9% in men, 4.9% in women). The majority of these cases were found to be mild in degree, and only a minority of these subjects had received physician diagnosis or treatment. Multivariate analysis revealed that age over 65 years, male sex, smoking more than 20 pack-years, and low income were independent predictors for chronic obstructive pulmonary disease. CONCLUSIONS: Seventeen percent of Korean adults over the age of 45 years have mild chronic obstructive pulmonary disease.

Comparison of drug resistance genotypes between Beijing and non-Beijing family strains of Mycobacterium tuberculosis in Korea.

The frequency of resistance genotypes among Beijing and non-Beijing strains was compared using a reverse blot hybridization assay to detect mutations within genes associated with rifampicin (rpoB) and isoniazid (katG, inhA, and ahpC) resistance. Of the 743 Mycobacterium tuberculosis isolates, 569 (77%) belonged to Beijing family. The proportion of Beijing strains was significantly higher among MDR-TB isolates than among drug-susceptible strains (82% vs. 72%, p<0.01). Genotype analysis of the rpoB gene revealed significantly lower rates of the Ser531Leu mutation rate among Beijing vs. non-Beijing MDR-TB strains (41% vs. 66%, p<0.005). While the mutation for Ser315Thr in the katG gene was more common among Beijing vs. non-Beijing family strains (65% vs. 50%, p<0.01), the mutation rate of promoter region of the inhA gene was lower among Beijing strains compared with non-Beijing strains (14% vs. 25%, p<0.05). Reverse hybridization successfully detected over 80% of isoniazid-resistant strains and over 92% of rifampicin-resistant strains among Korean isolates. Significant differences in mutation rates in the rpoB, katG, and inhA genes between Beijing strains and non-Beijing strains could explain discrepancies in mutation rates of genotypes in different countries. Reverse hybridization was useful for rapid detection of isoniazid and rifampicin resistant strains.