Multidrug-resistant pulmonary tuberculosis among young Korean soldiers in a communal setting

Global prevalence of drug-resistant tuberculosis: a systematic review and meta-analysis

BACKGROUND

Tuberculosis is a bacterial infectious disease, which affects different parts of a human body, mainly lungs and can lead to the patient's death. The aim of this study is to investigate the global prevalence of drug-resistant tuberculosis using a systematic review and meta-analysis.

METHODS

In this study, the PubMed, Scopus, Web of Science, Embase, ScienceDirect and Google Scholar repositories were systematically searched to find studies reporting the global prevalence of drug-resistant tuberculosis. The search did not entail a lower time limit, and articles published up until August 2022 were considered. Random effects model was used to perform the analysis. The heterogeneity of the studies was examined with the I² test. Data analysis was conducted within the Comprehensive Meta-Analysis software.

RESULTS

In the review of 148 studies with a sample size of 318,430 people, the I² index showed high heterogeneity (I² = 99.6), and accordingly random effects method was used to analyze the results. Publication bias was also examined using the Begg and Mazumdar correlation test which indicated the existence of publication bias in the studies (P = 0.008). According to our meta-analysis, the global pooled prevalence of multi-drug resistant TB is 11.6% (95% CI: 9.1-14.5%).

CONCLUSIONS

The global prevalence of drug-resistant tuberculosis was found to be very high, thus health authorities should consider ways to control and manage the disease to prevent a wider spread of tuberculosis and potentially subsequent deaths.

Multidrug Resistant Mycobacterium tuberculosis Among Military and Civilian Personnel seen at a Tertiary Military Hospital, Manila, Philippines (2015-2018)

INTRODUCTION

About one third of the world population is estimated to be infected with Mycobacterium tuberculosis (MTB), and this proportion is expected to be higher in countries with a high tuberculosis (TB) burden. The Philippines is both a high tuberculosis burden and a high multidrug resistant tuberculosis (MDR-TB) burden country. Though TB has been extensively described in the civilian population, there is limited data on TB in the military population. The objectives are: (1) To determine MTB/MDR-TB prevalence among military and civilian patients in the Philippines presenting with clinically suspected TB in a tertiary military hospital and (2) To determine performance of direct sputum smear microscopy (DSSM) using Ziehl-Neelsen (ZN) staining compared to Xpert MTB/RIF real-time reverse transcriptase polymerase chain reaction.

MATERIALS AND METHODS

Sputum samples were obtained from patients, clinically suspected with TB, and/or with TB associated signs/symptoms. Sputum specimens were tested using DSSM with ZN staining and Xpert MTB/RIF assay (Cepheid, Sunnyvale, California) and patient demographic and clinical data were collected.

RESULTS

From March 2015 to December 2018, a total of 795 (173 military personnel [164 active duty and 9 retired]; 618 civilians; and 4 with no data on military/civilian status) patients with TB associated symptoms or clinically suspected with TB were tested. Overall, MTB prevalence was 81/795 (10%). MTB prevalence among active duty and retired military personnel were 27/164 (16%) and 4/9 (44%), respectively while MTB prevalence for civilian patients was 50/618 (8%) (p value = 0.0003; OR = 2.48 [95% C.I. 1.5-4]). Among active and retired military personnel who tested positive for MTB, rifampin resistance was 4/27 (15%) and 1/4 (25%), respectively, while rifampin resistance for civilian patients was 9/50 (18%) (p value = 1; OR = 0.88 [95% C.I. 0.26-2.90]). For active duty military personnel, average MTB prevalence (based on Xpert MTB/RIF) covering years 2015-2018 was 21% and ranged from 13% to 35%, while average rifampin resistance among MTB positive active duty military personnel was 15% and ranged from 0% to 25%. Overall sensitivity and specificity of DSSM compared to Xpert MTB/RIF were 70% and 96%, respectively. Positive and negative predictive values of DSSM to accurately categorize MTB in symptomatic cases (with Xpert MTB/RIF as "true positive" reference) were 74% and 95%, respectively. Performance of DSSM varied according to MTB load detected by Xpert MTB/RIF with increasing DSSM sensitivity observed as the MTB load detected by Xpert MTB/RIF increased (p = 0.02).

CONCLUSION

This report describes high MTB and MDR-TB prevalence rates among symptomatic military patients with military personnel having higher odds of MTB infection compared to the civilian patients in the study. Since DSSM (ZN) sensitivity greatly varied depending on MTB load, the Xpert MTB/RIF should be used as a first-line diagnostic tool to identify MTB and detect rifampin resistance among presumptive TB cases instead of DSSM (ZN) microscopy.

The Infectivity of Pulmonary Tuberculosis in Korean Army Units: Evidence from Outbreak Investigations

Background

Tuberculosis (TB) causes substantial health burden to the Korean military. This study aims to assess the impact of infectious TB cases on close and casual contacts in the Korean Army settings based on contact investigation data.

Methods

Six Army units with infectious TB cases from September 2012 to May 2013 were enrolled in the study. We analyzed the clinical data from close and casual contacts screened using the tuberculin skin test (TST) and QuantiFERON-TB Gold In-Tube to identify latent tuberculosis infection (LTBI) cases. For the control group, 286 military conscripts with no reported TB exposure were tested by TST only.

Results

Of the 667 contacts of index cases, LTBI cases identified were as follows: 21.8% of close contacts of smear-positive cases (71/326), 8.5% of casual contacts of smear-positive cases (26/305), and 2.8% of close contacts of smear-negative cases (1/36). In the control group, 16.8% showed positivity in TST. In a multivariate analysis, having stayed in the same room or next room with TB patients was identified as a risk factor of LTBI.

Conclusion

Using the data from TB contact investigations in the Korean Army units, we found an overall LTBI rate of 14.7% among the contacts screened. This study demonstrates that contacts living in the same building, especially the same room or next room, with TB patients are at a high risk of acquiring LTBI, serving as additional evidence for defining close and casual contacts of a TB patient with regard to Army barrack settings.

Army Soldiers' Knowledge of, Attitude Towards, and Preventive Behavior Towards Tuberculosis in Korea

Objectives

The aim of this study was to gather information about Korean Army soldiers’ attitude towards tuberculosis to enable the development of an informed educational program and potential intervention plans.

Methods

There were 500 male soldiers serving in the Korean Army who responded to questionnaires regarding knowledge of, attitudes towards, and preventive behavior towards tuberculosis. The questionnaires were collected between September 10 until October 1, 2014. Participants’ characteristic that influenced differences in knowledge, attitudes, and preventive behavior towards tuberculosis were compared by t test. Variables that influenced preventive behavior were identified by multiple regression analysis.

Results

The mean scores assessing knowledge of, attitude, and preventive behavior towards tuberculosis were 11.64 (± 4.03) out of 20 points, 3.21 (± 0.38) out of 4 points, and 2.88 (± 0.42) out of 4 points, respectively. Non-smokers were more knowledgeable about tuberculosis than smokers. Participants who had family or friends with tuberculosis had better knowledge and a more productive attitude to tuberculosis. Participants who were educated or obtained information about tuberculosis, received better scores in all areas of knowledge, attitude and preventive behavior compared to other participants. Non-smoking, family or friends who have had tuberculosis, obtaining information about tuberculosis, and positive attitudes towards treatment and preventive education had an explanatory power of 24.6% with regard to preventive behavior against tuberculosis.

Conclusion

More relatable, systemized education should be provided regularly to improve soldiers’ knowledge of, attitudes towards, and prevention against tuberculosis in the Republic of Korea Army.

Association between tobacco smoking and drug-resistant tuberculosis

Background

Tobacco smoking is a risk factor for tuberculosis but little is known about the relationship between tobacco smoking and drug-resistant tuberculosis (DR-TB). We undertook a systematic review and meta-analysis to quantitatively assess the association between DR-TB and tobacco smoking.

Methods

We searched for relevant studies in the Ovid MEDLINE, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure, WANFANG, and WEIPU data-bases from inception to September 1, 2017. Results were expressed as odds ratios (ORs) with accompanying 95% CIs, and subgroup analyses were performed by study design, smoking type, DR-TB type, and multivariate analysis.

Results

Thirty-three studies related to tobacco smoking and DR-TB were included. We found substantial evidence that tobacco smoking is associated with an increased risk of DR-TB (OR 1.57, 95% CI 1.33–1.86). Associations were also found in subgroup analyses: for multidrug-resistant tuberculosis (OR 1.49, 95% CI 1.19–1.86) and for any DR-TB (OR 1.70, 95% CI 1.3–2.23); the pooled OR was 1.45 (95% CI 1.11–1.90) for current smoking, 2.25 (95% CI 1.46–3.47) for past smoking, and 1.56 (95% CI 1.22–1.98) for smoking history; and similar ORs were also observed in study design and multivariate analysis subgroup analysis.

Conclusion

This study demonstrated that tobacco smoking is an independent risk factor for DR-TB.

Risk factors associated with multidrug-resistant tuberculosis (MDR-TB) in a tertiary armed force referral and teaching hospital, Ethiopia

Background

Ethiopia is one of the world health organization defined higher tuberculosis (TB) burden countries where the disease remains a massive public health threat. This study aimed to identify the prevalence and associated factors of multidrug-resistant tuberculosis (MDR-TB) using all armed force and civilian TB attendants in a tertiary level armed force hospital, where data for MDR-TB are previously unpublished.

Methods

Cross-sectional study was conducted from September 2014 to August 2015 in a tertiary level Armed Force Referral and Teaching Hospital (AFRTH), Ethiopia. Armed force members (n = 251) and civilians (n = 130) which has been undergone TB diagnosis at AFRTH were included. All the specimens collected were subjected to microscopic smear observation, culture growth and drug susceptibility testing. Data were analyzed using statistical package for social sciences following binary logistic regression and Chi-square. P-values < 0.05 were considered statistically significant.

Results

Among 381 TB patients, 355 (93.2%) new and 26 (6.8%) retreatment cases were identified. Culture and smear positive TB cases were identified in 297 (77.9%) and 252 (66.1%) patients, respectively. The overall prevalence of MDR-TB in AFRTH was found 1.8% (1.3% for armed force members and 0.5% for civilian patients) all of which were previously TB treated cases. The entire treatment success rates were 92.6% achieved highest in the armed force (active and pension) than the civilian patients. The failure and dead cases were also found 2.5 and 4.6%, respectively. Using bivariate analysis, category of attendants and TB contact history were strong predictors of MDR-TB in armed force and civilian patients. Moreover, human immunodeficiency virus (HIV) infection also identified a significant (OR = 14.6; 95% CI = 2.3–92.1; p = 0.004) predicting factor for MDR-TB in armed force members. However, sex, age and body mass index were not associated factor for MDR-TB.

Conclusions

In AFRTH, lower prevalence of MDR-TB was identified in armed force and civilian patients that were significantly associated with category of attendants, HIV infection and TB contact history. Considering armed force society as one segment of population significantly helps to plan a better MDR-TB control management, especially for countries classified as TB high burden country.

Prevalence and risk factors of drug-resistant extrapulmonary tuberculosis

BACKGROUND

Physicians are usually aware of the occurrence of drug-resistant (DR) pulmonary tuberculosis (PTB), but lack concern about DR-extrapulmonary TB (EPTB). Data regarding the prevalence and risk factors of DR-EPTB remain limited.

OBJECTIVES

To determine the prevalence and risk factors of DR-EPTB.

METHODS

A retrospective study was performed in patients who had culture-proven Mycobacterium tuberculosis (MTB) from various specimens between January 2013 and December 2015. Patients were classified into three groups: PTB, EPTB and concomitant PTB and EPTB (PTB + EPTB). Clinical data, chest radiographic extent of disease and patterns of DR were collected.

RESULTS

There were 1014 culture-proven MTB specimens (716 pulmonary specimens and 298 extrapulmonary specimens) from 986 patients (648 PTB, 218 EPTB and 120 PTB + EPTB). The prevalences of isoniazid-, rifampicin- and multidrug-resistant EPTB were 7.8%, .5% and .5%, respectively, which were lower than those of PTB. When PTB and EPTB coexisted, a higher rate of DR-TB was observed than for PTB alone. Of 338 EPTB patients, the extent of radiographic disease was associated with isoniazid-, rifampicin- and multidrug-resistant TB. Previous history of TB and use of steroids/immunosuppressive drugs were also associated with rifampicin- and multidrug-resistant TB in multivariate analysis.

CONCLUSIONS

The prevalence of DR-EPTB was high in patients who had concomitant PTB. Although the prevalences of rifampicin- and multidrug-resistant TB were low in isolated EPTB, the prevalence of isoniazid-resistant TB remained high. Therefore, drug susceptibility testing should be performed in EPTB patients, especially those who carry the aforementioned risk factors.

Risk Factors for Multidrug-Resistant Tuberculosis among Patients with Pulmonary Tuberculosis at the Central Chest Institute of Thailand

There are limited data available on the risk factors for multidrug-resistant tuberculosis (MDR-TB). Therefore, we here conducted a retrospective matched case-control study among adults with pulmonary TB who received treatment at the Central Chest Institute of Thailand (CCIT) between January 2007 and December 2013, in order to determine the risk factors associated with MDR-TB among patients with pulmonary TB. We identified 145 patients with pulmonary MDR-TB (cases) and 145 patients with drug-sensitive pulmonary TB (controls). Multivariate analysis identified the independent risk factors for MDR-TB as follows: (1) ≥ 2 episodes of prior pulmonary TB (odds ratio [OR] 39.72, 95% confidence interval (95% CI) 7.86-200.66), (2) duration of illness > 60 days (OR 3.08, 95% CI 1.52-6.22), (3) sputum acid fast bacilli smear 3+ (OR 13.09, 95% CI 4.64-36.91), (4) presence of lung cavities (OR 3.82, 95% CI 1.89-7.73), and (5) presence of pleural effusion (OR 2.75, 95% CI 1.06-7.16). Prior pulmonary TB management with a non-category I regimen (P = 0.012) and having treatment failure or default as treatment outcomes (P = 0.036) were observed in a higher proportion among patients with MDR-TB. Particular characteristics of lung cavities, including the maximum diameter ≥ 30 mm (P < 0.001), the number of cavities ≥ 3 (P = 0.001), bilateral involvement (P < 0.001), and ≥ 2 lung zones involved (P = 0.001) were more commonly observed in patients with MDR-TB. In conclusion, these clinical factors and chest radiographic findings associated with MDR-TB among patients with pulmonary TB may help physicians to provide proper management of cases for prevention of the development and spread of MDR-TB in future.

Drug-resistance pattern of Mycobacterium tuberculosis strains from patients with pulmonary and extrapulmonary tuberculosis during 2006 to 2013 in a Korean tertiary medical center

BACKGROUND/AIMS

We evaluated the trend in the rates of drug-resistant tuberculosis (TB) over time, as well as the difference in the drug-resistance pattern between pulmonary tuberculosis (PTB) and extrapulmonary tuberculosis (EPTB) at a private referral center in South Korea.

METHODS

All patients with culture-confirmed TB from 2006 to 2013 were included.

RESULTS

In total, 1,745 patients were included: 1,431 (82.0%) were new cases, and 314 (18.0%) were cases treated previously; 1,610 (92.3%) were diagnosed with PTB, and 135 (7.7%) were diagnosed with EPTB. Multidrug-resistant (MDR) and extensively drug-resistant (XDR) TB were detected in 5.8% and 2.0% of new cases and in 20.1% and 8.6% of previously treated cases, respectively. The MDR TB rate during the study period decreased remarkably, whereas the MDR and XDR TB rates decreased significantly in previously treated cases. No difference in the drug-resistance rate was detected between PTB and EPTB.

CONCLUSIONS

The TB drug-resistance rate, particularly that of MDR TB, remained high at a private referral hospital, and the drug-resistance rate did not decrease significantly from 2006 to 2013. This finding underscores the need for a national survey regarding the prevalence of drug-resistant TB to obtain the most accurate and current drug-resistance status in South Korea, including the private sector.

Significant risk and associated factors of active tuberculosis infection in Korean patients with inflammatory bowel disease using anti-TNF agents

AIM: To evaluate the incidence and risk factors of Korean tuberculosis (TB) infection in patients with inflammatory bowel disease (IBD) undergoing anti-TNF treatment.

METHODS: The data of IBD patients treated with anti-TNFs in 13 tertiary referral hospitals located in the southeastern region of Korea were collected retrospectively. They failed to show response or were intolerant to conventional treatments, including steroids or immunomodulators. Screening measures for latent TB infection (LTBI) and the incidence and risk factors of active TB infection after treatment with anti-TNFs were identified.

RESULTS: Overall, 376 IBD patients treated with anti-TNF agents were recruited (male 255, mean age of anti-TNF therapy 32.5 ± 13.0 years); 277 had Crohn’s disease, 99 had ulcerative colitis, 294 used infliximab, and 82 used adalimumab. Before anti-TNF treatment, screening tests for LTBI including an interferon gamma release assay or a tuberculin skin test were performed in 82.2% of patients. Thirty patients (8%) had LTBI. Sixteen cases of active TB infection including one TB-related mortality occurred during 801 person-years (PY) follow-up (1997.4 cases per 100000 PY) after anti-TNF treatment. LTBI (OR = 5.76, 95%CI: 1.57-21.20, P = 0.008) and WBC count < 5000 mm³ (OR = 4.5, 95%CI: 1.51-13.44, P = 0.007) during follow-up were identified as independently associated risk factors.

CONCLUSION: Anti-TNFs significantly increase the risk of TB infection in Korean patients with IBD. The considerable burden of TB and marked immunosuppression might be attributed to this risk.

Treatment outcome and mortality among patients with multidrug-resistant tuberculosis in tuberculosis hospitals of the public sector

This study was conducted to evaluate treatment outcome, mortality, and predictors of both in patients with multidrug-resistant tuberculosis (MDR-TB) at 3 TB referral hospitals in the public sector of Korea. We included MDR-TB patients treated at 3 TB referral hospitals in 2004 and reviewed retrospectively their medical records and mortality data. Of 202 MDR-TB patients, 75 (37.1%) had treatment success and 127 (62.9%) poor outcomes. Default rate was high (37.1%, 75/202), comprising 59.1% of poor outcomes. Male sex (adjusted odds ratio [aOR], 2.91; 95% confidence interval [CI], 1.13-7.49), positive smear at treatment initiation (aOR, 5.50; 95% CI, 1.22-24.90), and extensively drug-resistant TB (aOR, 10.72; 95% CI, 1.23-93.64) were independent predictors of poor outcome. The all-cause mortality rate was 31.2% (63/202) during the 3-4 yr after treatment initiation. In conclusion, the treatment outcomes of patients with MDR-TB at the 3 TB hospitals are poor, which may reflect the current status of MDR-TB in the public sector of Korea. A more comprehensive program against MDR-TB needs to be integrated into the National Tuberculosis Program of Korea.