Making a timely diagnosis of pulmonary tuberculosis

Timely Pulmonary Tuberculosis Diagnosis Based on the Epidemiological Disease Spectrum: Population-Based Prospective Cohort Study in the Republic of Korea

BACKGROUND

Timely pulmonary tuberculosis (PTB) diagnosis is a global health priority for interrupting transmission and optimizing treatment outcomes. The traditional dichotomous time-divided approach for addressing time delays in diagnosis has limited clinical application because the time delay significantly varies depending on each community in question.

OBJECTIVE

We aimed to reevaluate the diagnosis time delay based on the PTB disease spectrum using a novel scoring system that was applied at the national level in the Republic of Korea.

METHODS

The Pulmonary Tuberculosis Spectrum Score (PTBSS) was developed based on previously published proposals related to the disease spectrum, and its validity was assessed by examining both all-cause and PTB-related mortality. In our analysis, we integrated the PTBSS into the Korea Tuberculosis Cohort Registry. We evaluated various time delays, including patient, health care, and overall delays, and their system-associated variables in line with each PTBSS. Furthermore, we reclassified the scores into distinct categories of mild (PTBSS=0-1), moderate (PBTBSS=2-3), and severe (PBTBSS=4-6) using a multivariate regression approach.

RESULTS

Among the 14,031 Korean patients with active PTB whose data were analyzed from 2018 to 2020, 37% (n=5191), 38% (n=5328), and 25% (n=3512) were classified as having a mild, moderate, and severe disease status, respectively, according to the PTBSS. This classification can therefore reflect the disease spectrum of PTB by considering the correlation of the score with mortality. The time delay patterns differed according to the PTBSS. In health care delays according to the PTBSS, greater PTB disease progression was associated with a shorter diagnosis period, since the condition is microbiologically easy to diagnose. However, with respect to patient delays, the change in elapsed time showed a U-shaped pattern as PTB progressed. This means that a remarkable patient delay in the real-world setting might occur at both apical ends of the spectrum (ie, in both mild and severe cases of PTB). Independent risk factors for a severe PTB pattern were age (adjusted odds ratio 1.014) and male sex (adjusted odds ratio 1.422), whereas no significant risk factor was found for mild PTB.

CONCLUSIONS

Timely PTB diagnosis should be accomplished. This can be improved with use of the PTBSS, a simple and intuitive scoring system, which can be more helpful in clinical and public health applications compared to the traditional dichotomous time-only approach.

Updates in pulmonary drug-resistant tuberculosis pharmacotherapy: A focus on BPaL and BPaLM

Drug-resistant tuberculosis (TB) is a major public health concern and contributes to high morbidity and mortality. New evidence supports the use of shorter duration, all-oral regimens, which represent an encouraging treatment strategy for drug-resistant TB. As a result, the landscape of drug-resistant TB pharmacotherapy has drastically evolved regarding treatment principles and preferred agents. This narrative review focuses on the key updates of drug-resistant TB treatment, including the use of short-duration all-oral regimens, while calling attention to current gaps in knowledge that may be addressed in future observational studies.

Engaging frontline providers: an important key to eliminating tuberculosis in Canada, and other high-income countries

The greatest human cost of the rapidly moving pandemic of SARS-CoV-2 may be due to its impact on the response to other diseases. One such other disease is tuberculosis (TB). All indications suggest that COVID-19-related diversions of healthcare resources and disruptions to public health programming will exacerbate the slower moving pandemic of TB. This is expected to set back TB elimination efforts by years. This is a prediction that is especially relevant to Canada, which has repeatedly failed to meet pre-set targets for the elimination of TB even before the COVID-19 pandemic began. A collaborative approach to achieve TB elimination, one that engages all care providers, has recently been emphasized by the STOP-TB Partnership. Among TB elimination strategies, frontline providers (e.g., family physicians, emergency room physicians, and others) are well positioned to identify candidates for the treatment of latent TB infection, and make the diagnosis of infection-spreading cases of TB in a timely manner, thereby interrupting forward-moving chains of transmission. Electronic medical records offer the promise of automating these processes. In this commentary, we promote broader engagement of the workforce across multiple sectors of medicine to reduce TB associated morbidity and mortality, interrupt transmission, and shrink the reservoir of latent TB infection.

Prompt recognition of infectious pulmonary tuberculosis is critical to achieving elimination goals: a retrospective cohort study

INTRODUCTION

All pulmonary tuberculosis (PTB) cases are presumed to be infectious to some degree. This spectrum of infectiousness is independently described by both the acid-fast bacilli smear and radiographic findings. Smear-positive patients with chest radiographic findings that are typical for adult-type PTB are believed to be most infectious.

HYPOTHESIS

Characterisation of the presumed most infectious PTB case is possible by reference to readily available clinical features and laboratory results.

METHODS

Retrospective cohort study of adult, culture-positive PTB cases (151 smear-positive; 162 smear-negative) diagnosed between 1 January 2013 and 30 April 2017 in Canada. We describe cases according to demographic, clinical and laboratory features. We use multivariable multinomial logistic regression to estimate the relative risk ratio (RRR) with 95% CI of features associated with an outcome of smear-positive PTB, characterised by 'typical' chest radiograph findings.

RESULTS

Being Canadian-born, symptomatic, having a subacute duration of symptoms and broad-spectrum antibiotic prescriptions were all more commonly associated with smear-positive than smear-negative disease (36% vs 20%; 95% vs 63%; 88% vs 54%; and 59% vs 28%, respectively). After combining smear status and radiographic features, we show that smear-positive patients with typical chest radiographs were younger, had a longer duration of symptoms (RRR 2.41; 95% CI 1.01 to 5.74 and 2.93; 95% CI 1.20 to 7.11, respectively) and were less likely to be foreign-born, or have a moderate to high-risk factor for reactivation (RRR 0.40; 95% CI 0.17 to 0.92 and 0.18; 95% CI 0.04 to 0.71, respectively) compared with smear-negative patients with atypical chest radiograph findings.

CONCLUSION

A clear picture of the presumed most infectious PTB case emerges from available historical and laboratory information; vigilance for this presentation by front-line providers will support elimination strategies aimed at reducing transmission.

Factors Associated with Health-Seeking Preference Among People Who Were Supposed to Cough for More Than 2 Weeks: A Cross-Sectional Study in Southeast China

BACKGROUND

The health-seeking preference of people with a cough >2 weeks had not been extensively researched in southeast China. The study aimed to explore factors associated with health-seeking preference, which could provide more evidence to improve individuals' appropriate health-seeking behavior.

MATERIALS AND METHODS

From October 2018 to December 2018, this cross-sectional study was conducted in Zhejiang, China. A questionnaire was used to collect information on sociodemographic characteristics, knowledge of tuberculosis (TB), and health-seeking preference. The chi-square test and multivariable logistic regression were performed to evaluate factors associated with health-seeking preference.

RESULTS

Of the 7174 participants, 3321 (46.3%) were men, 6148 (85.7%) were married, and 6013 (83.8%) knew about TB. Appropriate health-seeking preference was reported by 6229 (86.8%) participants. Respondents knowing about TB were more likely to seek appropriate care than those did not (89.6% vs 72.4%, p<0.001). Of the 6013 participants knowing about TB, respondents with higher scores on five key items of TB knowledge were more likely to get appropriate health-seeking preference. About 805 (96.6%) participants with 5 scores on TB knowledge had appropriate care preference. Only 97 (72.4%) participants with a score of 0 reported an appropriate preference. Multivariable logistic regression showed residence, marital status, education level, occupation, and awareness of TB knowledge were predictors of appropriate health-seeking preference. Compared to participants with a score of 0 on five TB key knowledge, participants with a score of 5 were 8.57 times more likely to have appropriate health-seeking preference (95% confidence interval [CI]: 4.97-14.78), followed by a score of 4 (odds ratio [OR]=5.99, 95% CI, 3.23-8.03); 3 (OR=3.74, 95% CI, 2.44-5.74); 2 (OR=1.99, 95% CI, 1.30-3.02) and 1 (OR=1.17, 95% CI, 0.76-1.80).

CONCLUSION

Participants with little knowledge of TB had a low level of appropriate health-seeking preference. Appropriate health-seeking preference of the participants improved with increased key knowledge level of TB.

Risk factors for mortality among inpatients with smear positive pulmonary tuberculosis

Objective

To evaluate risk factors having significant effect on mortality of smear positive Pulmonary Tuberculosis (PTB) inpatients.

Methods

A descriptive cross-sectional study was conducted at Ojha Institute of Chest Diseases, Dow University Hospital Ojha Campus, Karachi. One hundred and seventy (170) inpatients of smear positive PTB confirmed by Acid Fast Bacilli (AFB) smear, aged between 13-80 years were enrolled by using consecutive sampling technique while patients with drug resistant Tuberculosis (TB) and extra pulmonary TB were excluded from the study. Selected patients were interviewed for collecting demographic data and risk factor data by using a standard questionnaire.

Results

Out of 170 PTB inpatients, mortality was observed in 23 (13.5%) patients among which male patients were 12 (52.2%), and female were 11 (47.8%). Mortality was significantly associated with increasing age (p=0.003), socioeconomic status (p=0.019), anemia (p=0.03), Chronic Liver Disease (CLD) (p=0.005), Diabetes Mellitus (DM) (p=0.001), Human Immunodeficiency Virus (HIV) (p=0.007), Hypertension (HTN) (p=0.006), recurrent TB (p=0.001), and smoking (p=0.001).

Conclusion

Increasing age, poverty, smoking history, and presence of comorbidities like DM, CLD, HIV, hypertension, and anemia are associated with higher mortality in smear positive PTB cases.

Determinants of Health Care-Seeking Delay among Tuberculosis Patients in Rural Area of Central China

Background The prevalence of tuberculosis (TB) in low and middle-income countries is a significant public health and social concern. TB is a common infectious disease caused by the Mycobacterium tuberculosis infection, which has a widespread infection rate. Health care-seeking delay maybe one of the most important neglected risk factors for the spread of TB. Objectives The aim of this study was to understand the situation of health care-seeking delay among rural tuberculosis patients in Hubei Province, and explore its risk factors. Methods A total of 1408 rural tuberculosis patients were surveyed using a standard structured questionnaire in three cities of Hubei Province during the past two years. Results For the 1408cases of pulmonary tuberculosis, 39.70% of them were health care-seeking delayed. Logistic regressions indicate that the Han nationality, farming careers, the over 45 min walk to the township’s hospital, and awareness of the national TB free treatment policy, were significantly associated with higher odds of a delay in care seeking. Conclusions The prevalence of health care-seeking delay among tuberculosis patients was high in rural areas. It is essential to take comprehensive targeted interventions to reduce care-seeking delay.

Predicting pulmonary tuberculosis in immigrants: a retrospective cohort study

Our objective was to investigate whether pulmonary tuberculosis (PTB) can be predicted from features of a targeted medical history and basic laboratory investigations in immigrants.

A retrospective cohort of 391 foreign-born adults referred to the Edmonton Tuberculosis Clinic (Edmonton, AB, Canada) was studied using multiple logistic regression analysis to predict PTB. Seven characteristics of disease were used as explanatory variables. Cross-validation assessed performance. Each predictor was tested on two outcomes: “culture-positive” and “smear-positive”. Receiver operating characteristic (ROC) curves were generated and the area under the ROC curve (AUC) was quantified.

Symptoms, subacute duration of symptoms, risk factors for reactivation of latent TB infection and anaemia were all associated with a positive culture (adjusted OR 1.79, 2.24, 1.72 and 2.28, respectively; p<0.05). Symptoms, inappropriate prescription of broad-spectrum antibiotics and a “typical” chest radiograph were associated with smear-positive PTB (adjusted OR 2.91, 1.55 and 12.34, respectively; p<0.05). ROC curve analysis was used to test each model, yielding AUC=0.91 for the outcome “culture-positive” disease and AUC=0.94 for the outcome “smear-positive” disease.

PTB among the foreign-born can be predicted from a targeted medical history and basic laboratory investigations, raising the threshold of suspicion in settings where the disease is relatively rare.

In high-income, low tuberculosis incidence countries, certain clinical characteristics should raise the threshold of suspicion to confirm a timely diagnosishttp://ow.ly/bRDZ30iPurz

Chest Radiographic Patterns and the Transmission of Tuberculosis: Implications for Automated Systems

BACKGROUND

Computer-aided detection to identify and diagnose pulmonary tuberculosis is being explored. While both cavitation on chest radiograph and smear-positivity on microscopy are independent risk factors for the infectiousness of pulmonary tuberculosis it is unknown which radiographic pattern, were it detectable, would provide the greatest public health benefit; i.e. reduced transmission. Herein we provide that evidence.

OBJECTIVES

1) to determine whether pulmonary tuberculosis in a high income, low incidence country is more likely to present with "typical" adult-type pulmonary tuberculosis radiographic features and 2) to determine whether those with "typical" radiographic features are more likely than those without such features to transmit the organism and/or cause secondary cases.

METHODS

Over a three-year period beginning January 1, 2006 consecutive adults with smear-positive pulmonary tuberculosis in the Province of Alberta, Canada, were identified and their pre-treatment radiographs scored by three independent readers as "typical" (having an upper lung zone predominant infiltrate, with or without cavitation but no discernable adenopathy) or "atypical" (all others). Each patient's pre-treatment bacillary burden was carefully documented and, during a 30-month transmission window, each patient's transmission events were recorded. Mycobacteriology, radiology and transmission were compared in those with "typical" versus "atypical" radiographs.

FINDINGS

A total of 97 smear-positive pulmonary tuberculosis cases were identified, 69 (71.1%) with and 28 (28.9%) without "typical" chest radiographs. "Typical" cases were more likely to have high bacillary burdens and cavitation (Odds Ratios and 95% Confidence Intervals: 2.75 [1.04-7.31] and 9.10 [2.51-32.94], respectively). Typical cases were also responsible for most transmission events-78% of tuberculin skin test conversions (p<0.002) and 95% of secondary cases in reported close contacts (p<0.01); 94% of secondary cases in "unreported" contacts (p<0.02).

CONCLUSION

As a group, smear-positive pulmonary tuberculosis patients with typical radiographic features constitute the greatest public health risk. This may have implications for automated detection systems.

Primary care pearls to help eliminate tuberculosis in Canada

Although Canada has a low incidence of tuberculosis (TB), certain populations, including the foreign-born and Canadian-born Indigenous peoples, continue to be disproportionately represented among reported cases. The overall incidence rates of active TB in Canada have not significantly changed in the past decade and work still needs to be done to reach TB elimination goals set by the World Health Organization (WHO). In trying to achieve TB elimination in Canada, primary care clinicians, with the support of public health professionals and TB experts, can help by focusing on 1) targeted screening and treatment of latent TB infection (LTBI) and 2) timely diagnosis and referral of active TB disease. The following article focuses on some key primary care considerations to keep in mind in day-to-day patient care. To help conduct targeted screening and treatment for LTBI, several key populations, including immigrants from high TB burden countries, Indigenous peoples and several other at-risk groups, are outlined. Reactivation of LTBI plays a significant role in TB burden and is likely an area of major potential impact in achieving TB elimination. Advancement in LTBI treatment, including short course therapy, is also described. In addition, to help make a timely diagnosis of active TB, several key risk factors, including several co-morbidities which increase the risk of developing TB disease, can be considered. Being front-line in patient care, keeping in mind some of these key pearls may aid primary care providers to have potential impact on eliminating TB in Canada.